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It has not been taken from tY}he CCITT Class 2 documentation, which is copyrighted by the CCITT. This information is provided for educational purposesZ} only. To fully understand this information requires a through knowledge of the T.4 fax image and the T.30 fax session p[}rotocol standards. Due to the nature of this information, Supra's engineers and technical support can not and will not pro\}vide any help or support on this information. While a majority of this information is correct, neither Supra nor Rockwel]}l implies or warranties that the SupraFaxModem will work exactly as documented here. This information is based on an earl^}y draft of Class 2, which has undergone further revisions and changes by the CCITT TR29.2 committee. We STRONGLY urge an_}yone attempting to develop fax software to get the required documentation from Global Engineering or the TIA. SHORT HIST`}ORY OF CLASS 1 AND 2 In 1988 the CCITT TR29.2 committee accepted the Class 1 standard for communication between fax softa}ware and fax modems. The committee also voted on, but did not accept for various technical reasons, the Class 2 standardb}. A year later, they had slightly revised the standard but again did not accept it. Software and hardware manufactures dec}cided to unofficially adopt this standard until the TR29.2 committee could develop an acceptable standard. Since so manyd} companies have used the unoffical standard, the TR29.2 committee has designated that when the standard is offically adope}ted it will be known as Class 2.0. Over the last year or so, the TR29.2 committee has voted on several revisions to the f}Class 2 standard. Their last vote was early May '92. A no vote for technical reasons was entered. The TR29.2 committee ig}s now reviewing the technical issues that were raised. At this time, Supra has not heard of a projected date for the nexh}t ballot. WHAT IS THE DIFFERENCE BETWEEN CLASS 1 AND 2 Class 1 fax software handles all of the T.4 fax image and T.30 si}ession protocol information and timming. Thus, the ability to communicate properly with various fax machines is more a fj}unction of the software than the fax modem. Class 2 fax software generates a T.4 fax page image and sends it to the faxk} modem a page at a time. The fax modem then handles the T.30 session protocol information and timming. This relieves thl}e computer's cpu from some work. The ability to communicate properly with various fax machines is more a function of the fm}ax modem than the software. However, to further complicate matters, class 2 fax software can issue Class 1 commands and n}take over some of the duties of the Class 2 fax modem. When customers have a problem communicating correctly with a o}fax machine/modem, it can be very difficult to determine which is at fault, the software or the hardware. Supra has collp}ected numerous Class 1 and 2 fax software for a variety of different computers. When we receive a report of a problem, wq}e use these programs to determine if it is a software or hardware problem. If it is a hardware problem, we notify Rockwer}ll, otherwise we notify the software company. BUG REPORTS Supra is dedicated to making the best product for the best prs}ice. If you feel that you have found a bug, please fax or send a letter to the attention of: SUPRA V32/BIS FAX BUGt} Please fully describe the 'bug' (specific steps to generate it, phone numbers to call, make and model of fax/modem, revu} of our ROM (from I3 command) ), why you believe that it is a bug, what specific section of Class 2 applies to this bug av}nd how you would like the bug to be fixed. Please remember that there are issues that have not been addressed or settledw} by the TR29.2 committee in the Class 2 specifications. (i.e. how the DCD and DTR lines are handled while in fax mode.) x} WHERE TO GET OFFICIAL FAX DOCUMENTATION Telecommunications Industry Association 1722 Eye St. NW Suite 440 Wasy}hington, DC 20006 You need to ask for: Class 1 documentation - EIA/TIA-578 Class 2 documentation - Electronicz} Industries Association and Telecommunications Industry Association TIA Project Number 2388, Asynchronous Facsimile DCE C{}ontrol Standard, Service Class2, TR-29.2 Committee Letter Ballot Global Engineering Documents |}2805 McGaw Ave Irvin, CA 92713 800-854-7179 714-261-1455 714-261-7892 (Fax) You need to ask for: }} EIA/TIA-578 - Class 1 documentation EIA/TIA-592 - Class 2 documentation CCITT v7.3 - T.1 - T.90 standards, includ~}es T.4 & T.30 (The cost for the above docs will run close to $200. But Global will also update you on any changes or ad}ditions to those standards you purchase.) Global Engineering will not have the Class 2 documentation until approx. a m}onth after the TR29.2 committee accepts it. Most of those companies which have developed Class 2 fax software either sit o}n the TR29.2 committee or know someone who does. It may be possible to receive the documentation from the TIA if you pre}sent a credible proposal. Supra has no knowledge of what this proposal should consist of or who you need to talk to. } 7.1 COMMAND SYNTAX AND GUIDELINES 7.1.1 DTE COMMANDS The ISO 646 character set (T.50 International Alphabet 5, Ameri}can Standard Code for Information Interchange) is used for the issuance of commands and responses. Only the low-order 7 }bits of each character are used for commands or parameters; the high order bit is ignored. Upper case characters are equ}ivalent to lower case characters. For Phase C data transmission or reception, all 8 bits are needed. DTE COMMAND LINES } A command line is a string of characters sent from a DTE to the DCE while the DCE is in a command state. Command lines }have a prefix, a body, and a terminator. The prefix consists of the ASCII characters 'AT' (065, 084) or 'at' (097, 116).} The body is a string of commands restricted to printable ASCII characters, (032-126). Space characters (ASCII 032) and} control characters other than CR (013) and BS (010) in the command string are ignored. The default terminator is the ASCI}I character. Characters that precede the AT prefix are ignored. BSIC COMMAND SYNTAX Characters within the comma}nd line are parsed as commands with associated parameter values. The basic commands consist of single ASCII characters, }or single characters preceded by a prefix character (e.g., '&'), followed by a decimal parameter. Missing decimal parame}ters are evaluated as 0. EXTENDED COMMAND SYNTAX The facsimile commands use extended syntax. They are preceded by the } '+F' characters, and they are terminated by the semicolon ';' character (059) or by the that terminated the command }line. AT+FAA=0 ;+FCR 1 This command instructs the DCE to answer automatically a data or fax cal}l and also enables reception. AT+FCLASS=0 for data mode AT+FCLASS=1 for Service Cla}ss 1 Fax AT+FCLASS=2 for Service Class 2 Fax In Class 2, the DCE makes and terminates calls, manages t}he communication session and negotiates (T.30 protocol) and transports the image date to DTE. The T.4 protocol managemen}t of image data, etc. is done by DTE. The response to AT+FCLASS=0 in Data Mode or } AT+FCLASS=2 in Service Class 2 Fax is OK The service class may be set by the DTE fro}m the choices available using the '+FCLASS=' command. GENERAL RULES 1. +Fnnn commands must be entered complet}ely otherwise an ERROR response is sent. 2. All response messages are preceded and followed by . Mult}iple response commands, e.g., +FDIS:+FCSI: and +FDCS, will therefore appear to a have a blank line between them. 3. } Fax Class 2 commands can be separated by the ";" character. The ";" can be omitted if desired. Note that non-data co}mmands cannot be separated by ";" which is allowed as a dial modifier. 4. All class 2 commands are assumed to be th}e final command on a command line. Additional characters will be ignored. 5. An ERROR message will be generated if} any of the following conditions: a. A class 1 command is received while in Class 2. b. A Class 2 c}ommand is received while in Class 1. c. A Class 1 or Class 2 action command is received while in data m}odem mode d. A Class 2 read-only parameter is given the "=" form of a +F command (e.g., AT+FAXERR=5). } e. A class 2 action command is given the inappropriate "=" or "=?" (e.g., AT+FDR=?). 7.1.2 SERIAL POR}T SPEED AND FLOW CONTROL During fax mode, the DTE-DCE port speed is 19200 bps. The DCE provides a speed buffer of 1024 }bytes and provides DC1/DC3 (XON/XOFF) or RTS/CTS method of controlling the data into the buffer. This flow control is co}ntrolled by AT&K3 or AT&K4 command. This method of data flow control is available only for DTE to DCE direction of data.} There is no provision for data flow control from DCE to DTE. DATA STREAM TERMINATION The DCE exchanges streams of d}ata with the DTE while executing data transfer commands. These use data stream termination described in Section 3.2/ISO }2111. The ASCII character (016) is used as a special character to shield special characters. The chara}cter pair (<106><003>) is used to mark the end of a stream. The following patterns are used: any data.... } end of stream any data.... single in data any data.... delete DTE to DCE STREAMS The DCE filters the data stream from the DTE, and removes all character pairs beginning with }. The DCE recognizes as the stream terminator. The DCE recognizes and reinserts a single } in its place. The DTE must filter stream data to the DCE, and insert extra characters ahead of data. DCE TO }DTE STREAMS The DTE must filter the data stream from the DCE, and remove all character pairs beginning with . The }DTE must recognize as the stream terminator. The DTE must recognize and reinsert a single in} its place. The DCE filters stream data to the DTE, and inserts extra characters ahead of data. 7.1.3 AUTO ANS}WER The DCE can answer as a data DCE or as a fax DCE. It can answer the call adaptively, i.e. it can determine whether }call is 'data' or 'fax'. The +FAA parameter controls this feature. AT+FAA=1 ; Auto answer as a facsimile} or a ; data modem depending on call CONNECT xxx ; DCE status response if data call } +FCON ; DCE status response if fax call 7.1.4 IDENTIFICATION OF T.30 OPTIONS Group 3 devices negot}iate session parameters in DIS, DCS and DTC frames. These parameters are defined in table 8.2. 7.1.5 SESSION STATUS RE}PORTING The DCE provides reports to the DTE on the status of a session. The DCE provides following status reports: 1}. Connection and hang up status: +FCON +FHNG:<0-255> 2. Requested DIS session parameters +FDIS: reports remote facsimile capabilities. Syntax:+FDIS:VR, BR, WD, LN, DF, EC, BF, ST 3. +FDCS: reports the negotiated parameters 4. Phase C prompts: XON, XOFF, DC2 5. Phase C base status reports: de}pending upon copy quality and related end-of page status: +FPTS:<1-5> 7.1.6 PROCEDURE INTERRRUPT NEGOTI}ATION CCITT allows a station to request a procedure interruption at the end of a page. This request is passed between s}tations by the PIP, PIN, and PRI-Q messages. TABLE 7-1. FAX CLASS 2 COMMANDS ----------------------------------------}------------------- | Command Function | |------------------------------------------}---------------| | SERVICE CLASS ID | |---------------------------------------------}------------| | +FCLASS= Service Class | |------------------------------------------------}---------| | CLASS 2 ACTION COMMANDS | |---------------------------------------------------}------| | D Originate a call | | A Answer a call } | | +FDT= Data Transmission | | +FET=N Transmit Page Punctuation }| | +FDR Begin or Continue Phase C Receive Data | | +FK Session Termination | }|---------------------------------------------------------| | CLASS 2 DCE RESPONSES | |--}-------------------------------------------------------| | +FCON Facsimile Connection Response | | +F}DCS: Report Current Session | | +FDIS: Report Remote Identification | | +FCFR} Indicate Confirmation to Receive | | +FTSI: Report the Transmit Station ID | | +FCSI: } Report the Called Station ID | | +FPTS: Page Transfer Status | | +FET: } Post Page Message Response | | +FHNG Call Termination with Status | |-----------------}----------------------------------------| | CLASS 2 SESSION PARAMETERS | |--------------------}-------------------------------------| | +FMFR? Identify Manufacturer | | +FMDL? Iden}tify Model | | +FREV? Identify Revision | | +FDCC= DCE Cap}abilities Parameters | | +FDIS= Current Sessions Parameters | | +FDCS= Current Se}ssion Results | | +FLID= Local ID String | | +FCR Capability to} Receive | | +FPTS= Page Transfer Status | | +FAA Adaptive Answer } | | +FBUF? Buffer Size (Read Only) | | +FPHCTO Phase C Time Out } | | +FAXERR Fax Error Value | | +FBOR Phase C Data Bit Order} | |---------------------------------------------------------| 7.2 SERVICE CLASS 2 IDENTIFICATION AND SEL}ECTION The fax class 2 commands are summarized in Table 7-1. Three commands report identification and selection informa}tion. Each of these three commands cause the DCE to send a message to the DTE. Each message is 20 bytes (ASCII encoded)} followed by the terminating character (binary 0). 7.2.1 +FMFR?, REQUEST MANUFACTURER IDENTIFICAITION The +FMFR? comm}and caused the DCE to send a message identifying the DCE product manufacturer. The default message is: ROCKWELL } OK 7.2.2 +FMDL?, IDENTIFY PRODUCT MODEL The +FMDL? command causes the DCE to send a message identifying the DCE pr}oduct model. The default message is: V.32AC OK 7.2.3 +FREV?, IDENTIFY PRODUCT REVISION The +FREV? command c}auses the DCE to send a message identifying the DCE product model revision number. The typical default message is: }V0.200 TR14-JXXX-001 OK 7.3 SERVICE CLASS 2 ACTION COMMANDS These commands transfer data, and punctuate sessions.} They also release specific T.30 messages. All action commands must be the last command on a command line. This is ind}icated by the terminating . All action commands initiate processes. The modem will not accept other commands from t}he DTE until the modem issues a final result code (e.g. OK, CONNECT). The modem will abort the process if it receives any} character before the final result code is issued. 7.3.1 ATD, ORIGINATE A CALL Syntax: ATD... The DCE can }support a DTE command to originate a call using the ATD command (See Table 4-2). If this command is unsuccessful, the DC}E reports an appropriate failure or error type result code such as NO CARRIER, NO DIALTONE or BUSY (see Table 4-7). If} this call is successful, the typical DCE response is: ATDnn.nn (go off-hook, dial, get CED) +FCON } (DCE detects flags) [+FCSI:] +FDCS: OK The DCE dials, detects c}all progress and generates the CNG tone. Then it waits for a DIS frame. On detection of the first Phase B preamble (V.2}1 ch. 2 modulated by 300 bit/s HDLC flags) it reports the "+FCON" message to the DTE. The DCE then switches to 19.2K bps. } The DCE generates a DCS frame based on the received DIS frame and on the previously set +FDIS parameter. A +FDT command} from the DTE releases the DCE to transmit that DCS frame. The DCE reports the initial received T.30 negotiation message}s, including the DIS frame and the optional CSI ID string. The +FDIS: report is followed by the OK final result code. } 7.3.2 ATA, ANSWER A CALL The DCE can support a DTE command to answer an incoming call using the ATA command (see Table} 4-2). The DTE may issue an Answer command in response to an incoming ring. If the Answer command is unsuccessful, the }DCE will report an appropriate failure or error type result code, such as NO CARRIER (see 4-7) MANUAL CALL ANSWER I}f this call is successful, the typical DCE response (answer and receive) is: +FCON [+FTSI:] +F}DCS: OK (DTE should issue +FDR command here) On receipt of an Answer command from the DTE}, the DCE answer and generates the CED tone. The DCE then generates a DIS frame (derived from the +FDIS parameter) and h}unts for the first T.30 negotiation frames. On detection of the first Phase B preamble (V.21 ch 2 modulated by 300 bit/s} HDLC flags), it reports the "+FCON" message to the DTE. The DTE should report the initial received T.30 negotiation messa}ges, including the DCS frame. The +FCS: report will be followed by the OK final result code. AUTOMATIC ANSWER The }modem provides for automatic answering of incoming calls. If configured for automatic answer, the modem answers and incomi}ng call in compliance with T.30 and reports the same messages as described for manual answer. CONNECTIONS AS A DATA MO}DEM If configured to do so by the +FAA parameter, the DCE will adaptively answer as a facsimile DCE or as a data DCE. I}f the DCE answers as a facsimile DCE or as a data DCE. If the DCE answers as a data DCE, it resets the +FCLASS parameter} to 0 and issues the appropriate final result code (e.g. CONNECT or NO CARRIER) to the DTE. 7.3.3 +FDT, DATA TRANSMISSI}ON Syntax: +FDT The +FDT command prefixes Phase C data transmission. When the DCE is ready to accept Phase C dat}a, it issues the negotiation responses and the CONNECT result code to the DTE. In Phase B, the +FDT command releases the} DCE to proceed with negotiation, and releases the DCS message to the remote station. In Phase C, the +FDT command resum}es transmission after the end of a prior transmit data stream. INITIATE PAGE TRANSMISSION Phase B DCE polled response}: [+FCSI:] ; If new CSI received [+FDIS:] ; I}f new DIS received +FDCS: CONNECT ; When read}y for data After placing a call, or after finishing a document exchange, the DTE may command the DCE to re-enter T.30 Ph}ase B to attempt to negotiate a document transmission. CONTINUE A PAGE CONNECT The DTE may issue more} than one +FDT command for a given page, so that different files may be concatenated together. These files must have the } same format. PHASE C DATA FRAMING Phase C data must be presented to the DCE in stream mode. The DCE expects Phase C} data to follow until it detects termination characters. The DCE will filter the stream as described in Section} 7.1.2 The DCE will acknowledge the end of the data by returning the OK result code to the DTE. If there is data un}derrun before the next +FDT or +FET= command, the DCE will zero-fill pad as per T.4 until the Phase C timeout (+FPHCTO) is } reached, or until more data is received. The DCE appends an RTC pattern to the transmit data after an +FET= command is }received from the DTE. PHASE C DATA FORMAT The Phase C data will be of the format specified by the negotiated T.30 DC }S frame. The +FDCS response is defined in section 7.4.2. The subparameter values are described in table 7.2. }The DCE will use the negotiated minimum Scan Time parameter from the DCS frame , and insert sufficient fill bits to pad eac }h line to the minimum scan time. This is reported in the +FDCS:ST subparameter. If the DCE finds more than one consecut }ive EOL in Phase C data (e.g. RTC), it will send only one EOL. Note 1: Phase C data must conform to T.4 specifications } Note 2: The DTE need not include a final RTC, since the DCE will append an RTC in response to an FET= command } Note 3: Some facsimile machines may treat two EOLs as an RTC , ESCAPE FROM TRANSMISSION The DCE may request th }e DTE to halt Phase C transmission, by sending an cancel character (024) to the DTE. In this case, the DTE should }terminate Phase C transmission, issue , and wait for the OK response code from the DCE. Table 7-2 T.30 Session Sub }parameter Codes |-----------------------------------------------------------------| | Label | Function | Value | } Description | |--------|---------------|---------|------------------------------| | VR | Vertical } | 0 | Normal, 98 lpi | | | resolution | 1 | Fine, 196 lpi | |--------|- }--------------|---------|------------------------------| | BR | Bit Rate | 0 | 2400 bit/s V.27 ter | } | | | 1 | 4800 bit/s V.27 ter | | | (See note 1) | 2 | 7200 bit/s V.29 }or v.17 | | | | 3 | 9600 bit/s V.29 or v.17 | | | | **4 | 120 }00 bit/s V.33 or v.17 | | | | **5 | 14400 bit/s V.33 or v.17 | |--------|---------------|-- }-------|------------------------------| | WD | Page Width | 0 | 1728 pixels in 215 mm | | | } | 1 | 2048 pixels in 255 mm | | | | 2 | 2432 pixels in 303 mm | | } | | *3 | 1216 pixels in 151 mm | | | | *4 | 864 pixels in 107 m }m | |--------|---------------|---------|------------------------------| | LN | Page Length | 0 | A4, 297 } mm | | | | *1 | B4, 364 mm | | | | *2 } | unlimited length | |--------|---------------|---------|------------------------------| | DF | Data } | 0 | 1-D modified Huffman | | | Compression | 1 | 2-D modified Read | | } | Format | *2 | 2-D uncompressed mode | | | | *3 | 2-D modified Read } | |--------|---------------|---------|------------------------------| | EC | Error | 0 | Disable ECM } | | | Correction | *1 | Enable ECM,64 bytes/frame | | | (Annex | *2 | } Enable ECM,256 bytes/frame | | | A/T.30) | | | | | (See Note 2 }) | | | |--------|---------------|---------|------------------------------| | BF | } Binary File | 0 | Disable BFT | | | Transfer | *1 | Enable BFT }| | | (See Note 3) | | | |--------|---------------|---------|----------------- }-------------| | ST | Scan Time/ | | VR=normal VR=fine | | | Line | 0 | }0 ms 0 ms | | | | 1 | 5 ms 5 ms | | | | !} 2 | 10 ms 5 ms | | | | 3 | 10 ms 10 ms | | | "} | 4 | 20 ms 10 ms | | | | 5 | 20 ms 20 ms | | #} | | 6 | 40 ms 20 ms | | | | 7 | 40 ms 40 ms $} | |--------|---------------|---------|------------------------------| | NOTES: 1: CCITT T.30 does not provide for %} the answering | | station to specify all speeds exactly using the DIS | | frame. Implementa &}tion of some BR codes (e.g.code 2) | | by an answering DCE is manufacturer specific. | | '} | | | | (} * =Not supported | | ** =RC144AC only )} | | | | 2: ECM has been implemented in Supra's *} version 1.200C. | | ECM transmit works correctly, and ECM receive works, | | but does not tell the +}transmitting machine that the | | fax was received correctly. | | ,} | | 3: BFT has been implemented in Supra's version 1.200C. | | -} BFT transmit works correctly, and BFT receive works, | | but does not tell the transmitting machine that the .} | | file was received correctly. | | /} | |-----------------------------------------------------------------| 7.3.4 +FET=, TRANSMIT PAGE PUNCTUA 0}TION Syntax: +FET=[,,,] DCE response: +FPTS: ; when receive from remote OK This comman 1}d is used to punctuate page and document transmission after one or more +FDT commands. This command generates T.30 Post Pa 2}ge Messages selected by the code (Table 7-3) The +FET= command indicates that the current page is complete; n 3}o more data will be appended to it. The value indicates if there are any additional pages are to be sent and, if so, whe 4}ther there is a change in any of the document parameters. The DTE can command the DCE to generate PRI-Q messages with th 5}e +FET= command using ppm codes 4-6 (see Table 7-3) This command must be sent within the time out specified by +FPH 6}CTO after sending Phase C data, or else the DCE will end the page and document transmission. If the Phase C timeout is r 7}eached, the DCE sends an EOP post page message and terminates the session The remote facsimile station should respond to 8} the post page message with a post page response. The DCE will report this using the +FPTS: response (Table 7-4) 9} END A PAGE The +FET= command causes the DCE to append an ETC (6 EOL) pattern as needed and enter Phase D by sending the :} selected T.30 Post Page message. The +FET=1 (EOM) command signals the remote station that the next document will have a ;} new DCS negotiated; this causes the session to re- enter Phase B. 7.3.5 +FDR, BEGIN OR CONTINUE PHASE C RECEIVE DATA <} Syntax: +FDR Default value: 3 seconds in some places The +FDR command initiates transition to Phase C data rece =}ption. This can occur after answering, dialing, a document is received, or a page is received. The DCE reports the ne >}gotiated T.30 parameters, with the remote ID information if available. When the DCE is ready to commence data transfer, ?}it issues a CONNECT response code. If the DCE cannot resume data transfer because there is no more data, it responds OK. @}When the DTE is ready to accept data, it issues an character (018) to the DCE. If the DTE issues an chara A}cter to the DCE for flow control, the DCE signals the DTE when its buffers are empty by sending a (<016><018>) B} character pair. When the DCE delivers that last byte of a page, the DCE reports the Page Transfer Status via the +FPTS: C} response (Table 7-4). After a Page Transfer Status Report, the DCE reports the post page message from the remote f D}acsimile station via the +FET: response (Table 7-3) which signals the intentions of the remote station. Table 7-3 E}. T.30 Post Page Message Codes |-----------------------------------------------------------------| | ppm | F} | | | Code | Mnemonic | Description | |------- G}--|-----------------|-------------------------------------| | 1 | [PPS]-MPS | Another page next, same document H} | | 2 | [PPS]-EOM | Another page next | | 3 | [PPS]-EOP | no more pages or doc I}uments | | 4 | [PPS-]PRI-MPS | Another page, procedure interrupt | | 5 | [PPS-]PRI-EOM | Another J} doc, procedure interrupt | | 6 | [PPS-]PRI-EOP | All done, procedure interrupt | | 7 | CTC K} | Continue to correct | | 8-15 | EOR- | End of Retransmission (8)+ | | =8+ppm | L} | Post Page Message (ppm code) | |-----------------------------------------------------------------| M} Table 7-4. T.30 Post Page Response Message Codes |-----------------------------------------------------------------| N}| ppr | | | | Code | Mnemonic | Description O} | |---------|-----------------|-------------------------------------| | 0 | PPR | Partial page P} errors | | 1 | MCF | Page Good | | 2 | RTN | Q} Page bad, retrain requested | | 3 | RTP | Page good, retrain requested | | 4 | PIN R} | Page bad, interrupt requested | | 5 | PIP | Page good, interrupt requested | |--- S}--------------------------------------------------------------| The DCE holds the post page response message to the remote T} facsimile station (MCF, etc.), represented in the +FPTS parameter until the next +FDR command. The DTE may modify the + U}FPTS parameter before issuing the +FDR command which releases that message. The DTE must issue a +FDR command to release V} Post Page Messages. INITIATE DOCUMENT RECEPTION The +FDR command may be issued in Phase B after an answer command, or W}in Phase B after a pervious document. The DCE response in stream mode is: +FCR ; when CFR sent [+F X}TSI:] ; if new TSI received +FDCS:] ; if new DCS CONNECT ( nee Y}ded from DTE here) +FPTS:,[,,] +FET: OK (DT Z}E must issue +FDR command to release post page response) CONTINUE DOCUMENT RECEPTION The DTE may issue a +FDR command i [}n Phase D, which releases the post page message, and indicates readiness to receive another page after receipt of a Multi \}page (+FET:0) or PPS-NULL (+FET:3) message. The DCE response will be: CONNECT ( needed from DTE here) < ]}Phase C data stream> +FPTS:,[,,] +FET: OK (DTE must issue +FDR comman ^}d to release post page response. If done receiving: +FHNG: OK Continue page reception PH _}ASE C DATA FRAMING Phase C data may be presented to the DTE in stream mode. The DCE will transfer a stream of data to t `}he DTE, followed by the stream termination characters. The DCE will filter the stream as described in 7.1.2. a} PHASE C DATA FORMAT The received data format is negotiated under T.30 reported by the +FDCS:VR,BR,WD,LN,DF,EC,BF,ST r b}esponse. The DCE will delete the terminating RTC (6 EOLs) patterns. The DCE may strip zero fill bits from the data, to c}minimize storage needs. , ESCAPE FROM RECEPTION From the +FDR command until the end of Phase D Date, the DCE is in d} a data transfer state, and will not respond to DTE command characters. The DCE will respond to three ASCII control char e}acters, (019) flow control characters, and cancel (024). Upon receipt of the character, f} the DCE will terminate the reporting of received data by sending trailing characters to the DTE, and will the q}B%DOS SYSB*)DUP SYSBSFAXCLAS2TXTB,SCSI_FAQATAB8PSUPPLY TXTBPSUPPLY RMEn execute an implied +FK command in order to conduct an orderly disconnection. 7.3.6 +FK, SESSION TERMINATION Syntax r}: +FK The +FK command causes the DCE to terminate the session in an orderly manner. In particular, the DCE will send a s} DCN message at the next opportunity and hang up. At the end of the termination process, the DCE will report the +FHNG r t}esponse with result code (Table 7-5). This operation can be invoked by using the cancel character during Phase C d u}ata reception (see prior section). The DCE will wait until the current page completes, unless the reception is of unlimi v}ted length; in that case, the DCE may halt reception and terminate the session at any time. 7.4 SERVICE CLASS 2 DCE RES w}PONSES The DCE sends information responses to the DTE as a facsimile session proceeds. They indicate the state of the f x}acsimile session and convey need information. These messages are solicited messages generated in execution of DTE action y} commands described in section 7.3. The DCE precedes and follows the following information responses with . T z}he DCE provides the on-line status of several session parameters when they are available during T.30 handshaking. These in {}clude the remote ID string and the DIS/DCS parameters. These responses report the T.30 session parameter frames. The su |}bparameters are described in Table 7-2. 7.4.1 +FCON, FACSIMILE CONNECTION RESPONSE +FCON indicates connection with a f }}ax machine. It is released by detection of HDLC flags in the first received frame +FCON is generated in response to an O ~}riginate or Answer command. 7.4.2 +FDCS:, REPORT CURRENT SESSION CAPABILITIES Syntax: +FDCS:VR,BR,WD,LN,DF,EC,BF,ST } +FDCS: reports the negotiated parameters. Phase C data will be formatted as described by the subparameters. Th }is message may be generated in execution of +FDT or +FDR commands before the CONNECT result code if new DCS frames are ge }nerated of received. (See Table 7- 2.) 7.4.3 +FDIS:, REPORT REMOTE STATION CAPABILITIES Syntax: +FDIS:VR,BR,WD,LN, }DF,EC,BF,ST +FDIS: reports remote facsimile station capabilities and intentions. The parameters are provided in } ASCII notation. (See Table 7-2.) This message is generated in execution of Originate, Answer, +FDT, or +FDR commands }. 7.4.4 +FCFR, INDICATE CONFIRMATION TO RECEIVE Syntax: +FCFR The DCE sends a +FCFR response to the DTE upon recep }tion of an acceptable TCF training burst and a valid DCS signal from the remote machine. This indicates that the DCE wil }l receive Phase C data after the remote station receives the local DCE's CFR message. The +FCFR message is generated in }execution of a +FDR command. 7.4.5 +FTSI:, REPORT THE TRANSMIT STATION ID Syntax: +FTSI:"" Transmit St }ation ID This response reports the received transmit station ID string, if any. This message is generated in execution }of Originate, Answer, +FDT, or +FDR commands. 7.4.6 +FCSI:, REPORT THE CALLED STATION ID Syntax: +FCSI:"" Called Station ID This response reports the received called station ID string, if any. This message is generated } in execution of Originate, Answer, +FDT, or +FDA commands. 7.4.7 +FPTS:, RECEIVE PAGE TRANSFER STATUS Syntax: +FPT }S:,[,,] The +FPTS: is generated by the DCE at the end of Phase C data reception in execution of } a +FDR command. The is generated by the DCE; it depends on the DCE capabilities at T.4 error checking. See Table } 7-4 for values. The receiving DCE will count the lines and may optionally generate bad line counts. These values } are: = line count = bad line count = and write a modified value into the +FPTS parameter. The DCE will hold the corresponding Post Page Response mes }sage until released by a +FDR command from the DTE. 7.4.8 +FET:, POST PAGE MESSAGE RESPONSE Syntax: +FET: Th }e +FET: response is generated by a receiving DCE after DCE after the end of Phase C reception on receipt } of the post-page message from the transmitting station. The +GET: response is generated in execution of a +FDR com }mand. The codes respond to the T.30 pst page messages (Table 7-3) 7.4.9 +FPTS:, TRANSMIT PAGE TRANSFER STATUS } Syntax: +FPTS: The +FPTS: response reports a number representing the copy quality and related post page mes }sage responses received from the remote DCE. The set of valid values are defined in Table 7-4. The +FPTS: re }sponse is generated in execution of a +FET= command. 7.4.10 +FHNG:, CALL TERMINATION WITH STATUS Syntax: +FHNG }: +FHNG indicates that the call has been terminated. The hangup cause is reported and stored in the } +FAXERR parameter for later inspection. The values are described in Table 7-5. +FHNG: is a p }ossible intermediate result code to any DTE action command described in Section 7.3. It is always followed by the OK final } result code. Upon termination of a call, the DCE determines the cause of termination and reports it as part of the FH }NG: response. It also stores this code in the +FAXERR parameter for later inspection. The hangup values are }organized according to the phases of the facsimile transaction as defined by T.30. A COMREC error or RSPREC error indica }tes that one of two events occurred. 1) a DCN (disconnect) signal was received, or 2) an FCS error was detected and the in }coming signal was still present after 3 seconds. The table values are in decimal notation. Leading zero characters are } optional. Table 7-5 Hangup Status Codes |------------------------------------------------------------| | Code } | Cause Description | |----------|-------------------------------------------------| | 0 }-9 | CALL PLACEMENT AND TERMINATION | |----------|-------------------------------------------------| | } 0 | Normal and proper end of connection | | 1 | Ring Detect without successful handshake | | } 2 | Call aborted, from +FK or AN | | 3 | No Loop Current } | |----------|-------------------------------------------------| | 10-19 | TRANSMIT PHASE A & MISCELLANEOUS ERRORS } | |----------|-------------------------------------------------| | 10 | Unspecified Phase A error } | | 11 | No Answer (T.30 T1 timeout) | |----------|--------------------------------------- }----------| | 20-39 | TRANSMIT PHASE B HANGUP CODES | |----------|------------------------------------ }-------------| | 20 | Unspecified Transmit Phase B error | | 21 | Remote cannot receive or send } | | 22 | COMREC error in transmit Phase B | | 23 | COMREC invalid command recei }ved | | 24 | RSPEC error | | 25 | DCS sent three times with }out response | | 26 | DIS/DTC received 3 times; DCS not recognized | | 27 | Failure to train at 24 }00 bps or +FMINSP value | | 28 | RSPREC invalid response received | |----------|--------------------- }----------------------------| | 40-49 | TRANSMIT PHASE C HANGUP CODES | |----------|------------------ }-------------------------------| | 40 | Unspecified Transmit Phase C error | | 43 | DTE to DCE da }ta underflow | |----------|-------------------------------------------------| | 50-69 | TRANSMIT P }HASE D HANGUP CODES | |----------|-------------------------------------------------| | 50 | Unspeci }fied Transmit Phase D error | | 51 | RSPREC error | | 52 | No r }esponse to MPS repeated 3 times | | 53 | Invalid response to MPS | | 54 | N }o response to EOP repeated 3 times | | 55 | Invalid response to EOM | | 56 | } No response to EOM repeated 3 times | | 57 | Invalid response to EOM | | 58 } | Unable to continue after PIN or PIP | |----------|-------------------------------------------------| | 70 }-89 | RECEIVE PHASE B HANGUP CODES | |----------|-------------------------------------------------| | } 70 | Unspecified Receive Phase B error | | 71 | RSPREC error | } | 72 | COMREC error | | 73 | T.30 T2 timeout, expected page not received } | | 74 | T.30 T1 timeout after EOM received | |----------|--------------------------------------------- }----| | 90-99 | RECEIVE PHASE C HANGUP CODES | |----------|------------------------------------------ }-------| | 90 | Unspecified Receive Phase C error | | 91 | Missing EOL after 5 seconds } | | 92 | Unused code | | 93 | DCE to DTE buffer overflow } | | 94 | Bad CRC or frame (ECM or BFT modes) | |----------|--------------------------------- }----------------| | 100-119 | RECEIVE PHASE D HANGUP CODES | |----------|------------------------------ }-------------------| | 100 | Unspecified Receive Phase D errors | | 101 | RSPREC invalid response r }eceived | | 102 | COMREC invalid response received | | 103 | Unable to continue aft }er PIN or PIP | |----------|-------------------------------------------------| | 120-255 | RESERVED CODES } | |------------------------------------------------------------| 7.5 SERVICE CLASS 2 PARAM }ETERS All Service Class 2 parameters can be read, written, and tested for range of legal values by the DCE. The general } syntax is described in Section 7.1. Group 3 FAX devices negotiate session parameters in DIS, DCS, and DTC frames. Th }e following parameters are provided to condition the facsimile DCE for the capabilities it will offer and to report the s }ession settings negotiated. The three primary T.30 session parameters are +FDCC, +FDIS and +FDCS. They are compound par }ameters, using values listed in Table 7-2. Figure 70-1 illustrates their relationships. 7.5.1 +FDCC, DCE CAPABILITIES }PARAMETERS Write Syntax: +FDCC:VR,BR,WD,LN,DF,EC,BF,ST Valid values See Table 7-2 Default values 0,3,0,2,0,0,0 },0 (RC96AC) 0,5,0,2,0,0,0,0 (RC144AC) +FDCC allows the DTE to sense and constrain the capabilities of t }he facsimile DCE from the choices defined in CCITT t.30 Table 2. When +FDCC is modified by the DTE, the DCE copies +FDCC } into +FDIS. 7.5.2 +FDIS, CURRENT SESSIONS CAPABILIIES PARAMETERS Write Syntax: +FDIS:VR,BR,WD,LN,DF,EC,BF,ST Val }id values See Table 7-2 Default values 0,3,0,2,0,0,0,0 (RC96AC) 0,5,0,2,0,0,0,0 (RC144AC) The }+FDIS parameter allows the DTE to sense and constrain the capabilities used for the current session. The DCE uses +FDIS to } generate DIS or DTC messages directly, and uses +FDIS and received DIS messages to generate DCS messages. The DCE ini }tializes the +FDIS parameter from the +FDCC parameter on initialization, when +FDCC is written, and at the end of a session }. 7.5.4 +FLID=, LOCAL ID STRING Write Syntax +FLID="" Valid values: 20 character ASCII string } Default value: Empty If FLID is not a null string, it generates a TSI or CSI frame. Table 3/T.30 includes digits 0- }9, "+" and space. If the DCE supports use of Table 3/t.30 only, the response to a +FLID=? command is "<20)(32, 43, 48-57 })". If the DCE supports printable ASCII <, the response is "(20)(32-127)" The first "(20)" represents string leng }th: the second (character values) field reports supported string values. Notes: 1. The string is saved in RAM. } 2. Non-numeric characters are not filtered out. 7.5.5 +FCR, CAPABILITY TO RECEIVE Write Syntax: +FCR= Va }lid values: 1,0 Default values 0 +FCR=0 indicates that the DCE will not receive message data. This can be sued when } the DTE has insufficient storage. The DCE can send and can be polled for a file. +FCR is sampled in CCITT T.30 Phase A } and Phase D 7.5.6 +FPTS=, PAGE TRANSFER STATUS Write syntax: +FPTS= Valid Values: 1,2,3,4,5 Default va }lue: 0 7.5.7 +FCQ, COPY QUALITY CHECKING Write Syntax: +FCQ= Valid Values: 0 Default Value: 0 This }parameter controls Copy Quality checking by a receiving facsimile DCE. The DCE returns +FCQ=0 which indicates the DCE do }es no quality checking. The DCE will generate Copy Quality OK (MCF) responses to complete pages, and set +FPTS=1. 7.5 }.8 +FPHCTO, DTE PHASE C RESPONSE TIME-OUT Write Syntax: +FPHCTO= Valid Values: 0-255, 100 millisecond units } Default Value: 30 The +FPHCTO command determines how long the DCE will wait for a command after reaching the end of } data when transmitting in Phase C. When this time-out is reached, the DCE assumes there are no more pages and no docume }nts to send. It then sends the T.30 EOP response to the remote device. 7.5.9 +FAXERR, T.30 SESSION ERROR REPORT Rea }d Syntax: +FAXERR=, read only Valid values: 0-255, see table 7-5 for meaning This read-only parameter i }ndicates the cause of the hangup. Table 7-5 shows the valid values for this parameter as well as the meaning of the each } value. +FAXERR is set by the DCE at the conclusion of a fax session. The DCE resets +FAXERR to 0 at the beginning of Pha }se A off- hook time. 7.5.10 +FBOR, DATA BIT ORDER Write Syntax: +FBOR= Valid Values: 0,1 Default value }: 0 This parameter controls the mapping between PSTN facsimile data and the DTE-DCE link. There are two choices: DI }RECT: The first bit transferred to each byte on the DTE-DCE link is the first bit transferred on the PSTN data carrier. } REVERSED: The last bit transferred of each byte on the DTE-DCE link is the first bit transferred on the PSTN data carrier }. There are two data types to control: This command controls Phase C data (T.4 encoded data) transferred during execu }tion of +FDT or +FDR commands. The following two codes are supported. +FBOR=0 selects direct bit order for Phase C d }ata +FBOR=1 selects reversed bit order for Phase C data Note that this parameter does not affect the bit order of }control characters generated by the DCE. 7.5.11 +FAA, ANSWER PARAMETER Write syntax: +FAA= Valid values: } 0,1 Default value 0 +FAA=0 constrains the DCE to answer as set by +FCLASS +FAA=1 indicates that the DC }E can answer and automatically determine whether to answer as a Class 2 facsimile DCE or as a data modem. If the DCE aut }omatically switches, if modifies FCLASS appropriately. Class 2 adaptive answer is implemented as follows: First, a da }ta mode handshake is attempted. If the DCE has been configured for automode detection (using the A command), the DCE may t }ry several protocols be terminating attempts to make a data mode connection. This can take as long as 6-8 seconds. If } the data mode connection attempt fails, a facsimile Class 2 connection is assumed. When a connection is made, a result of } the adaptive answer, the DCE issues the D or FAX result code before the CONNECT or +FCC message to inform the DTE of the } connection type. A making a class 2 connection, the DCE stays on-line rather than going into the command mode as with a } Class 2 connection. 7.5.12 +FBUF?, BUFFER SIZE Read syntax: +FBUF? DCE response syntax ,,, w }here: = total buffer size = XOFF threshold = XON threshold = current buffer byte count } The +FBUF parameter allows the DTE to determine the characteristics of the DCE's data buffer. Data buffers are used fo }r flow control. Use of the reported values allow the DTE to transfer data without provoking XOFF. 7.6 EXAMPLE SESS }IONS Table 7-6 and 7-7 show the typical command and responses for sending and receiving two pages respectively. } Table 7-6 Send two pages, 1-D data, no errors |-------------------------------------------------------------------- }--| | DTE COMMAND | DCE RESPONSE | LOCAL DTE ACTION |REMOTE STATION ACTION | |-------------|--------------|---------------- }--|----------------------| | AT+FCLASS=2 | OK | Set Class 2 | | |-------------|-------- }------|------------------|----------------------| | AT+FLID= | | | | }| | OK | Set local ID | | |-------------|--------------|------------------|-- }--------------------| | AT| | off hook, dial | answer | | | } | send CNG | send [CED], | | | +FCON | detect flags | v.21 flags | | } | +FDIS: | get CSI | CSI | | | +FDIS:| get DIS | DIS } | | | OK | | | |-------------|--------------|--- }---------------|----------------------| | AT+FDT | | send TSI | get TSI | | } | | send DCS | get DCS | | | | send TCF | get TCF } | | | +FDCS:| get CFR | send CFR | | | CONNECT | send ca }rrier | receive carrier | | | | | | | <1st page> | } | send page data | receive page data | | | OK | | } | |-------------|--------------|------------------|----------------------| | AT+FET=0 | | send RTC } | get RTC | | | | get MPS | send MPS | | | +FPT }S:1 | get MCF | send MCF | | | OK | | }| |-------------|--------------|------------------|----------------------| | AT+FDT | CONNECT | send carrier }| receive carrier | | | | | | | <2nd page> | } | send page data | receive page data | | | OK | | | |- }------------|--------------|------------------|----------------------| | AT+FET=2 | | send RTC | get } RTC | | | | send EOP | get EOP | | | +FPTS:1 | } get MCF | send MCF | | | +FHNG:0 | send DCN | get DCN | | } | OK | hangup | hangup | |-------------|--------------|------------------|--------- }-------------| Table 7-7 Receive two pages, 1-D data, no errors |---------------------------------------- }------------------------------| | DTE COMMAND | DCE RESPONSE | LOCAL DTE ACTION |REMOTE STATION ACTION | |-------------|--- }-----------|------------------|----------------------| | AT+FCR=1 | OK | Enable reception | } | |-------------|--------------|------------------|----------------------| | AT+FLID= | | } | | | | OK | Set local ID | | |-------------|-------- }------|------------------|----------------------| | | RING <- | detect ring <- | Dials[, send CNG] | }|-------------|--------------|------------------|----------------------| | ATA | | off hook | } | | | | send CED | get CED | | | } | send CSI | get CSI | | | | send DIS | get DIS | | } | +FCON | detect flags | send v.21 flags | | |[+FTSI:""] [get TSI] | [send }TSI] | | | +FDCS:| get DCS | send DCS | | | OK | be }gin TCF receive| start TCF | |-------------|--------------|------------------|----------------------| | AT+FDR } | | accept TCF | finish TCF | | | +FCFR | send CFR | get CFR } | | |[+FDCS:] | | | | CONNECT | get pag }e carrier | send page carrier | | | | get page data | send page data | | | } | | | | <-| detect RTC <- | send RTC !} | | | +FPTS:1, | | drop carrier | | | +FET:0 <- | get MPS "} <- | send MPS | | | OK | | | |-------------|----- #}---------|------------------|----------------------| | AT+FDR | | send MCF | get MCF $}| | | CONNECT | get page carrier | send page carrier | | | | get page data %}| send page data | | | | | | | <-| detect RTC <- | send RTC | | | +FPTS:1, | | drop carrier | | '} | +FET:2 <- | get EOP <- | send EOP | | | OK | | (} | |-------------|--------------|------------------|----------------------| | AT+FDR | | )} send MCF | get MCF | | | +FHNG:0 <- | get DCN <- | send DCN | | *} | OK | hangup | hangup | |-------------|--------------|------------------|--------- +}-------------| Newsgroups: comp.periphs.scsi,comp.answers,news.answersPath: bloom-beacon.mit.edu!hookup!news.kei.com!wang!newsFrom: garyf@-}wiis.wang.com (Gary Field)Subject: comp.periphs.scsi FAQ part 2 of 2Expires: Sun, 1 May 1994 05:00:03 GMTReply-To: garyf@w.}iis.wang.com (Gary Field)Organization: Wang Labs, Lowell MA, USADate: Mon, 4 Apr 1994 15:21:30 GMTApproved: news-answers-r/}equest@MIT.EduMessage-ID: Followup-To: comp.periphs.scsiSummary: This posting contains a list of Freq0}uently Asked Questions (and their answers) about SCSI. It should be read by anyone who wishes to p1}ost to the comp.periphs.scsi newsgroup.Sender: news@wang.comNntp-Posting-Host: gfield.wiis.wang.comLines: 1092}9Xref: bloom-beacon.mit.edu comp.periphs.scsi:13522 comp.answers:4769 news.answers:17656Archive-name: scsi-faq/part2 3} SCSI FAQ: Frequently Asked Questions for comp.periphs.scsi VOLUME IIVolume II Table of Contents: Wha4}t is the difference between SCSI-1 and SCSI-2? Is SYNCHRONOUS faster than ASYNCHRONOUS? Is the 53C90 Faster than spec5}? What are the jumpers on my Conner drive? What are the jumpers for my Wangtek 5150 drive? What is CAM? What 6}is FPT (Termination)? What is Active Termination? Why Is Active Termination Better? Why is SCSI more expensive th7}an IDE? What is Plug and Play SCSI? Where can I get drivers (ASPI and other) for the WD7000 FASST2 host adapter?===8}=QUESTION: What is the difference between SCSI-1 and SCSI-2?ANSWER From Dal Allen:==== SCSI-1_v9}ersus_SCSI-2In 1985, when the first SCSI standard was being finalized as an AmericanNational Standard, the X3T9.2 Task Gro:}up was approached by a group ofmanufacturers. The group wanted to increase the mandatory requirements ofSCSI and to define;} further features for direct-access devices. Rather thandelay the SCSI standard, X3T9.2 formed an ad hoc group to develop a<} workingpaper that was eventually called the Common Command Set (CCS). Many productswere designed to this working paper.=}In parallel with the development of the CCS working paper, X3T9.2 soughtpermission to begin working on an enhanced SCSI stan>}dard, to be called SCSI-2.SCSI-2 would include the results of the CCS working paper, caching commands,performance enhanceme?}nt features, and whatever else X3T9.2 deemed worthwhile.While SCSI-2 was to go beyond the original SCSI standard (now referr@}ed to asSCSI-1), it was to retain a high degree of compatibility with SCSI-1 devices.How is SCSI-2 different from SCSI-1?A}1. Several options were removed from SCSI-1: a. Single initiator option was removed. b. Non-arbitrating Systems opB}tion was removed. c. Non-extended sense data option was removed. d. Reservation queuing option was removed. e. ThC}e read-only device command set was replaced by the CD-ROM command set. f. The alternative 1 shielded connector wasD} dropped.2. There are several new low-level requirements in SCSI-2: a. Parity must be implemented. b. InitiatorsE} must provide TERMPWR -- Targets may provide TERMPWR. c. The arbitration delay was extended to 2.4 us from 2.2 us. d. F} Message support is now required.3. Many options significantly enhancing SCSI were added: a. Wide SCSI (up to 32 bitG}s wide using a second cable) b. Fast SCSI (synchronous data transfers of up to 10 Mega-transfers per second -- up H}to 40 MegaBytes per second when combined with wide SCSI) c. Command queuing (up to 256 commands per initiator on each logI}ical unit) d. High-density connector alternatives were added for both shielded and non- shielded connectors. eJ}. Improved termination for single-ended buses (Alternative 2) f. Asynchronous event notification g. Extended contingK}ent allegiance h. Terminate I/O Process messaging for time- critical process termination4. New command sets were addedL} to SCSI-2 including: a. CD-ROM (replaces read-only devices) b. Scanner devices c. Optical memory devices (proviM}des for write-once, read-only, and erasable media) d. Medium changer devices e. Communications devices5. AN}ll command sets were enhanced: a. Device Models were added b. Extended sense was expanded to add: + AdditionaO}l sense codes + Additional sense code qualifiers + Field replaceable unit code + Sense key specific byteP}s c. INQUIRY DATA was expanded to add: + An implemented options byte + Vendor identification field Q}+ Product identification field + Product revision level field + Vital product data (more extensive product repoR}rting) d. The MODE SELECT and MODE SENSE commands were paged for all device types e. The following commands were addS}ed for all device types: + CHANGE DEFINITION + LOG SELECT + LOG SENSE + READ BUFFER + WRIT}TE BUFFER f. The COPY command definition was expanded to include information on how to handle inexact block sizesU} and to include an image copy option. g. The direct-access device command set was enhanced as follows: + The FORMV}AT UNIT command provides more control over defect management + Cache management was added: - LOCK/UNLOCK CACW}HE command - PREFETCH command - SYNCHRONIZE CACHE command - Force unit access bit - DX}isable page out bit + Several new commands were added: - READ DEFECT DATA - READ LONG -Y} WRITE LONG - WRITE SAME + The sequential-access device command set was enhanced as follows: - PZ}artitioned media concept was added: * LOCATE command * READ POSITION command - Several mod[}e pages were added - Buffered mode 2 was added - An immediate bit was added to the WRITE FILEMARKS comman\}d + The printer device command set was enhanced as follows: - Several mode pages defined: * Dis]}connect/reconnect * Parallel printer * Serial printer * Printer options + The wri^}te-once (optical) device command set was enhanced by: - Several new commands were added: * MEDIUM SCAN_} * READ UPDATED BLOCK * UPDATE BLOCK - Twelve-byte command descriptor blocks were defined f`}or several commands to accommodate larger transfer lengths.====================================================a}=========================The following article was written by Dal Allan of ENDL in April 1990. It was published nine montb}hs later in the January 1991 issue of "Computer Technology Review". While it appeared in the Tape Storage Technology Sectic}on of CTR, the article is general in nature and tape-specific. In spite of the less than timely publication, most of the ind}formation is still valid.It is reprinted here with the permission of the author. If you copy this article, please include}e this notice giving "Computer Technology Review" credit for first publication.-------------------------------------------f}----------------------------------- What's New in SCSI-2Scuzzy is the pronunciation and SCSI (Sg}mall Computer System Interface) is the acronym, for the best known and most widely used ANSI (American National Standards Ih}nstitute) interface. Despite use of the term "Small" in its name, everyone has to agree that Scuzzy is large - in use, in i}market impact, in influence, and unfortunately, in documentation. The standards effort that began with a 20-page specificatj}ion in 1980 has grown to a 600 page extravaganza of technical information. Even before ANSI (American National Standards Ik}nstitute) published the first run of SCSI as standards document in 1986, ASC (Accredited Standards Committee) X3T9.2 was hal}rd at work on SCSI-2. No technical rationale can be offered as to why SCSI-1 ended and SCSI-2 began, or as to why SCSI-2 em}nded and SCSI-3 began. The justification is much more simple - you have to stop sometime and get a standard printed. Popularn} interfaces never stop evolving, adapting, and expanding to meet more uses than originally envisaged. Interfaces even livo}e far beyond their technological lifespan. SMD (Storage Module Drive) has been called technically obsolete for 5 years but ep}very year there are more megabytes shipped on the SMD interface than the year before. This will probably continue for anothq}er year or so before the high point is reached, and it will at least a decade before SMD is considered to be insignificant.r} If SCSI enhancements are cut off at an arbitrary point, what initiates the decision? Impatience is as good an answer as as}ny. The committee and the market get sick of promises that the revision process will "end soon," and assert pressure to "dot} it now."The SCSI-3 effort is actively under way right now, and the workload of the committee seems to be no less than it u}was a year ago. What is pleasant, is that the political pressures have eased. There is a major difference between the stanv}dards for SCSI in 1986 and SCSI-2 in 1990. The stated goal of compatibility between manufacturers had not been achieved in w}SCSI in 1986 due to a proliferation of undocumented "features." Each implementation was different enough that new softwarex} drivers had to be written for each device. OEMs defined variations in hardware that required custom development programs ay}nd unique microcode. Out of this diversity arose a cry for commonality that turned into CCS (Common Command Set), and becamz}e so popular that it took on an identity of its own. CCS defined the data structures of Mode Select and Mode Sense commands{}, defect management on the Format command and error recovery procedures. CCS succeeded because the goals were limited, the |}objectives clear and the time was right. CCS was the beginning of SCSI-2, but it was only for disks. Tape and optical dis}}ks suffered from diversity, and so it was that the first working group efforts on SCSI-2 were focused on tapes and optical d~}isks. However, opening up a new standards effort is like lifting the lid on Pandora's Box - it's hard to stay focused on a }single task. SCSI-2 went far beyond extending and consolidating CCS for multiple device types. SCSI-2 represents three yea}rs of creative thought by some of the best minds in the business. Many of the new features will be useful only in advanced }systems; a few will find their way into the average user's system. Some may never appear in any useful form and will atrophy}, as did some original SCSI features like Extended Identify.Before beginning coverage of "what's new in SCSI-2," it might }be well to list some of the things that aren't new. The silicon chips designed for SCSI are still usable. No new features w}ere introduced which obsolete chips. The cause of silicon obsolescence has been rapid market shifts in integrating function}s to provide higher performance. Similarly, initiators which were designed properly, according to SCSI in 1986, will succe}ssfully support SCSI-2 peripherals. However, it should be pointed out that not all the initiators sold over the last few yea}rs behaved according to the standard, and they can be "blown away "by SCSI-2 targets. The 1986 standard allows either init}iators or targets to begin negotiation for synchronous transfers, and requires that both initiators and targets properly ha}ndle the sequence. A surprisingly large percentage of SCSI initiators will fail if the target begins negotiation. This has n}ot been as much of a problem to date as it will become in the future, and you know as well as I do, that these non-complian}t initiators are going to blame the SCSI-2 targets for being "incompatible." Quirks in the 1986 standard, like 4 bytes bei}ng transferred on Request Sense, even if the requested length was zero have been corrected in SCSI-2. Initiators which reli}ed on this quirk instead of requesting 4 bytes will get into trouble with a SCSI-2 target. A sincere effort has been made }to ensure that a 1986-compliant initiator does not fail or have problems with a SCSI-2 target. If problems occur, look for }a non-compliant initiator before you blame the SCSI-2 standard. After that little lecture, let us turn to the features you }will find in SCSI-2 which include: o Wide SCSI: SCSI may now transfer data at bus widths of 16 and 32 bits. Commands, st}atus, messages and arbitration are still 8 bits, and the B-Cable has 68 pins for data bits. Cabling was a confusing issue in} the closing days of SCSI-2, because the first project of SCSI-3 was the definition of a 16-bit wide P-Cable which supporte}d 16-bit arbitration as well as 16-bit data transfers. Although SCSI-2 does not contain a definition of the P-Cable, it is }quite possible that within the year, the P-Cable will be most popular non-SCSI-2 feature on SCSI-2 products. The market resp}onds to what it wants, not the the arbitrary cutoffs of standards committees. o Fast SCSI: A 10 MHz transfer rate for SCSI} came out of a joint effort with the IPI (Intelligent Peripheral Interface) committee in ASC X3T9.3. Fast SCSI achieves 10 }Megabytes/second on the A-Cable and with wider data paths of 16- and 32-bits can rise to 20 Megabytes/second and even 40 Me}gabytes/second. However, by the time the market starts demanding 40 Megabytes/second it is likely that the effort to seriali}ze the physical interface for SCSI-3 will attract high-performance SCSI users to the Fiber Channel. A word of caution. At} this time the fast parameters cannot be met by the Single Ended electrical class, and is only suitable for Differential. On}e of the goals in SCSI-3 is to identify the improvements needed to achieve 10 MHz operation with Single Ended components.} o Termination: The Single Ended electrical class depends on very tight termination tolerances, but the passive 132 ohm term}ination defined in 1986 is mismatched with the cable impedance (typically below 100 ohms). Although not a problem at low sp}eeds when only a few devices are connected, reflections can cause errors when transfer rates increase and/or more devices a}re added. In SCSI-2, an active terminator has been defined which lowers termination to 110 ohms and is a major boost to syst}em integrity. o Bus Arbitration, Parity and the Identify Message were options of SCSI, but are required in SCSI-2. All but} the earliest and most primitive SCSI implementations had these features anyway, so SCSI-2 only legitimizes the de facto ma}rket choices. The Identify message has been enhanced to allow the target to execute processes, so that commands can be issue}d to the target and not just the LUNs. o Connectors: The tab and receptacle microconnectors chosen for SCSI-2 are availa}ble from several sources. A smaller connector was seen as essential for the shrinking form factor of disk drives and other p}eripherals. This selection was one of the most argued over and contentious decisions made during SCSI-2 development. o R}otational Position Locking: A rose by any other name, this feature defines synchronized spindles, so than an initiator can m}anage disk targets which have their spindles locked in a known relative position to each other. Synchronized disks do not a}ll have to be at Index, they can be set to an offset in time relative to the master drive. By arraying banks of synchronize}d disks, faster transfer rates can be achieved. o Contingent Allegiance: This existed in SCSI-1, even though it was not d}efined, and is required to prevent the corruption of error sense data. Targets in the Contingent Allegiance state reject all} commands from other initiators until the error status is cleared by the initiator that received the Check Condition when t}he error occurred. Deferred errors were a problem in the original SCSI but were not described. A deferred error occurs in }buffered systems when the target advises Good Status when it accepts written data into a buffer. Some time later, if anythi}ng goes wrong when the buffer contents are being written to the media, you have a deferred error. o Extended Contingent A}llegiance (ECA): This extends the utility of the Contingent Allegiance state for an indefinite period during which the init}iator that received the error can perform advanced recovery algorithms. o Asynchronous Event Notification (AEN): This func}tion compensates for a deficiency in the original SCSI which did not permit a target to advise the initiator of asynchronou}s events such as a cartridge being loaded into a tape drive. o Mandatory Messages: The list of mandated messages has grow}n: +----------------------+--------------------------+-------------------+ | Both | Target } | Initiator | +----------------------+--------------------------+-------------------| | Identify } | Abort | Disconnect | | | | |} | Message Reject | No Operation | Restore Pointer | | | } | | | Message Parity Error | Bus Device Reset | Save Data Pointer | | | } | | | | Initiator Detected Error | | +--}--------------------+--------------------------+-------------------+ o Optional messages have been added to negotiate wide }transfers and Tags to support command queueing. A last-minute inclusion in SCSI-2 was the ability to Terminate I/O and rece}ive the residue information in Check Condition status (so that only the incomplete part of the command need be re-started b}y the initiator). o Command Queueing: In SCSI-1, initiators were limited to one command per LUN e.g. a disk drive. Now up }to 256 commands can be outstanding to one LUN. The target is allowed to re-sequence the order of command execution to optim}ize seek motions. Queued commands require Tag messages which follow the Identify. o Disk Cacheing: Two control bits are u}sed in the CDB (Command Descriptor Block) to control whether the cache is accessed on a Read or Write command, and some com}mands have been added to control pre-fetching and locking of data into the cache. Users do not have to change their software} to take advantage of cacheing, however, as the Mode Select/Mode Sense Cache page allows parameters to be set which optimiz}e the algorithms used in the target to maximize cache performance. Here is another area in which improvements have already }been proposed in SCSI-3, and will turn up in SCSI-2 products shipping later this year. o Sense Keys and Sense Codes have }been formalized and extended. A subscript byte to the Sense Code has been added to provide specifics on the type of error b}eing reported. Although of little value to error recovery, the additional information about error causes is useful to the en}gineer who has to analyze failures in the field, and can be used by host systems as input to prognostic analysis to anticip}ate fault conditions. o Commands: Many old commands have been reworked and several new commands have been added. o Pag}es: Some method had to be found to pass parameters between host and target, and the technique used is known as pages. The co}ncept was introduced in CCS and has been expanded mightily in SCSI-2. A number of new Common Commands have been added, and} the opcode space for 10-byte CDBs has been doubled. o Change Definition allows a SCSI-2 initiator to instruct a SCSI-2 t}arget to stop executing according to the 1986 standard, and provide advanced SCSI-2 features. Most SCSI-2 targets will powe}r on and operate according to the 1986 standard (so that there is no risk of "disturbing" the installed initiators, and wil}l only begin operating in SCSI-2 mode, offering access to the advanced SCSI-2 capabilities, after being instructed to do so }by the initiator using the Change Definition command. o The Mode Select and Mode Sense pages which describe parameters for} operation have been greatly expanded, from practically nothing in 1986 to hundreds of items in SCSI-2. Whenever you hear o}f something being described as powerful and flexible tool, think complicated. Integrators are advised to be judicious in th}eir selection of the pages they decide to support. o the Inquiry command now provides all sorts of interesting data about }the target and its LUNs. Some of this is fixed by the standard, but the main benefit may be in the Vendor Unique data segre}gated into the special designation of Vital Product Data, which can be used by integrators as a tool to manage the system e}nvironment. o Select Log and Sense Log have been added so that the initiator can gather both historical (e.g. all Check Co}nditions) and statistical (e.g. number of soft errors requiring ECC) data from the target. o Diagnostic capabilities have} been extended on the Read/Write Buffer and Read/Write Long commands. The ways in which the target can manage bad blocks in} the user data space have been defined further and regulated to reduce inconsistencies in the 1986 standard. A companion cap}ability to Read Defect Data permits the initiator to use a standard method to be advised of drive defect lists. o A new }group of 12-byte command blocks has been defined for all optical devices to support the large volume sizes and potentially l}arge transfer lengths. The Erase command has been added for rewritable optical disks so that areas on the media can be pre-}erased for subsequent recording. Write Once disks need Media Scan, so that the user can find blank areas on the media. o} New command sets have been added for Scanners, Medium Changers, and CD ROMs. All of this technical detail can get boring,} so how about some "goodies" in SCSI-2 which benefit the common man and help the struggling engineer? First, and probably t}he best feature in SCSI-2 is that the document has been alphabetized. No longer do you have to embark on a hunt for the Read} command because you cannot remember the opcode. In the 1986 standard, everything was in numeric sequence, and the only e}ngineers who could find things easily were the microprogrammers who had memorized all the message and opcode tables. Now, or}dinary people can find the Read command because it is in alphabetic sequence. This reorganization may sound like a small ma}tter but it wasn't, it required a considerable amount of effort on the part of the SCSI-2 editors. It was well worth it. A}nother boon is the introduction for each device class of models which describe the device class characteristics. The tape mo}del was the most needed, because various tape devices use the same acronym but with different meanings or different acronym}s for the same meaning. The SCSI-2 tape model defines the terms used by SCSI-2, and how they correspond to the acronyms of} the different tapes. For example, on a 9-track reel, End of Tape is a warning, and there is sufficient media beyond the re}flective spot to record more data and a trailer. Not so on a 1/4" tape cartridge, End of Tape means out of media and no more} data can be written. This sort of difference in terms causes nightmares for standardization efforts. So there it is, a s}ummary of what is in SCSI-2. It's not scary, although it is daunting to imagine plowing through a 600-page document. Time fo}r a commercial here. The "SCSI Bench Reference" available from ENDL Publications (408-867-6642), is a compaction of the sta}ndard. It takes the 10% of SCSI-2 which is constantly referenced by any implementor, and puts it in an easy-to-use referenc}e format in a small handbook. The author is Jeff Stai, one of the earliest engineers to become involved with SCSI implementa}tion, and a significant contributor to the development of both the 1986 standard and SCSI-2. SCSI-2 is not yet published }as a standard, but it will be available later this year. Until then, the latest revision can be purchased from Global Engin}eering (800-854-7179).BiographyConsultant and analyst I. Dal Allan is the founder of ENDL and publisher of the ENDL Lett}er and the "SCSI Bench Reference." A pioneer and activist in the development and use of standard interfaces, he is Vice Chai}rman of ASC X3T9.2 (SCSI) and Chairman of the SCSI-2 Common Access Method Committee. ====QUESTION: Is SYNCHRONOUS fas}ter than ASYNCHRONOUS?QUESTION: Is the 53C90 Faster than spec?From: kstewart@ncr-mpd.FtCollins.NCR.COM (Ken Stewart)====}I've seen a few comments about our 54C90 being faster than spec. WhileI doubt the author was really complaining (I got twic}e as much as I paid for--sure makes me mad ;) I'd like to explain the situation. Along the way, I'll also show that async}hronous is faster on short cables, while synchronous is faster on long cables. The cross-over point occurs somewhere aroun}d six feet--assuming that you have our 53C90 family devices at both ends of the cable. The reason has to do with the propag}ation delay of the cable; the turn around time of the silicon; and the interlocked natureof the asynchronous handshake.1)} We have measured propagation delays from various cables and found an average of 1.7 nanoseconds per foot, which is rou}ghly 5.25 ns per meter. 2) The turn-around time is the amount of time the SCSI chip takes to change an output in re}sponse to an input. If REQ is an input then ACK is an output. Or if ACK is an input then REQ is an output. Typical } turn-around time for the 53C90 is 40 nanoseconds. 3) The asynchronous transfer uses an interlocked handshake where a de}vice cannot do the next thing until it receives positive acknowledgment that the other device received the last thi}ng. First REQ goes true /* driven by Target */ then ACK is permitted to go true }/* driven by Initiator */ then REQ is permitted to go false then ACK is permitted to go false Thus we have four }"edges" propagating down the cable plus 4 turn-arounddelays. Asynchronous transfer requires 55 ns setup and no hold time (}paragraph in 5.1.5.1 in SCSI-1 or SCSI-2) which gives an upper speed limit around 18 MB/s. A detailed analysis (assuming 53}C90 family) shows thatthe setup time subtracts out. This is mostly because we are running at one-third the max rate, but a}lso because setup for the next byte can begin anytime after ACK is received true or REQ is received false, depending on who}is receiving. You can either take my word for it or draw the waveforms yourself. Thus, the asynchronous transfer reduces t}o:(4 * 1.7 * 1) + (4 * 40ns) = 167 ns /* 1 foot cable */ = 6 MB/s(4 * 5.25 * 6)} + (4 * 40ns) = 286 ns /* 6 meter cable */ = 3.5 MB/s(4 * 5.25 * 25) + (4 * 40ns)} = 685 ns /* 25 meter cable */ = 1.5 MB/s note: cables longer than 6 m}eters require external differential transceivers which add delay and degrade the performance even more than indicated here. }Our simulations say that under very best conditions (fast silicon, low temperature, high voltage, zero length cable) we can } expect more than 8 MB/s asynchronously. In the lab, I routinely measure 5 MB/s on 8 foot cables. So, if you were writing } the data manual for this, how would YOU spec it?The framers of the SCSI spec threw in synchronous mode to boost the perf }ormance on long cables. In synchronous mode, the sending device is permitted to send the next byte without receiving acknow }ledgment that the receiver actually received the last byte. Kind of a ship and pray method. The acknowledgment is require}d to come back sometime, but we just don't have to wait for it (handwave the offset stuff and the ending boundary condition}s). In this mode any external transceivers add a time shift, but not a delay. So if you negotiate for 5 MB/s, you get 5MB/}s regardless how long the cable is and regardless whether you are single-ended or differential. But you can't go faster th}an 5.5 MB/s, except in SCSI-2. Synchronous mode does have a hold time (unlike asynch) but again, setup andhold times subtr}act out. In SCSI-1 synchronous mode, the speed limit comes from the combined ASSERTION PERIOD + NEGATION PERIOD which is 9}0ns + 90ns = 180ns = 5.5 MB/s. Our 53C90 family doesn't quite hit the max,but we do guarentee 5.0 MB/s. In SCSI-2, anythin}g above 5.0 MB/s is considered to be FAST. Here the maximum transfer rate is explicitly limited to 100 ns or 10MB/s; you d}on't have to read between the lines to deduce it.Interesting tid-bit: given a SCSI-2 FAST period of 100 ns and a cable dela}yof 131 ns on a 25 meter cable, you can actually stack 1.31 bytes in the 8-bitcable. In FAST and WIDE SCSI you can stack 5}.24 bytes in this copper FIFO. Hummm...====QUESTION: What are the jumpers on my Conner drive?ANSWER From: ekrieger@qu}asar.hacktic.nl (Eric Krieger)Embellishment from: Henrik Stahl (f92-hst@nada.kth.se)==== QUICK INSTALLATION} GUIDE SCSI Most SCSI host adapters are compatible with Conner drives.Software drivers and i}nstallation instructions are provided withthe host adapter. The drives are shipped with SCSI ID set to 7. To select a}different ID refer to the following:Table A Table BID E-1 E-2 E-3 ID E2 E3 E40} out out out 0 out out out1 in out out 1 in out out2 out in out } 2 out in out3 in in out 3 in in out4 out out in 4 out out in5 in} out in 5 in out in6 out in in 6 out in in7 in in in 7 i}n in inParity is always ENABLED on the CP3200,CP30060,CP30080,CP30100,CP 30200, CP 3500, CP 3360, CP 30540 and CP 3137 }0.For the CP 340, jumper E-1 to disable parity.All other models, jumper E-4 to disable parity. SCSI drive parameter!}s: Model Hds Cyl Sec Table LED CP2020 2 642 32 A "} n/a CP340 4 788 26 B 1 CP3020 2 622 33 A #} 1 CP3040 2 1026 40 A 1 CP3180 6 832 33 A $} 1 CP3100 8 776 33 A 1 CP30060 2 1524 39 A %} 2 CP30080 4 1053 39 A 2 CP30100 4 1522 39 A &} 2 CP30200 4 2119 49 A 2 CP3200 8 1366 38 A '}2 CP3360 8 1806 49 A 2 CP3540 12 1806 49 A 2(} CP 30080E 2 1806 46 AA C/E CP 30170E 4 1806 46 AA C/)}E CP 30540 6 2249 59-89 AA B CP 31370 14 2094 59-95 AA B*}LED 1 LED 2J-4 Pin 1 = + J-1 Pin 3 = + Pin 2 = - Pin 4 = -On the CP 31370, jumper E5 e+}nables termination. Default is termination on.It may be the same jumper for other models.====QUESTION: What are the jum,}pers for my Wangtek 5150 drive?ANSWER From: "Terry Kennedy, Operations Mgr" ==== First, the -}disclaimer: This is not an official representation of Wangtekor of my employer. This is info I've discovered by reading publ.}icly avail-able reference material. When changing jumpers, always observe proper anti-static precautions and be sure you ha/}ve the current configuration writtendown so you have a known starting point. Ok. Here's the complete scoop on Wangtek 5150}0ES drives: The current part number for a "generic" 5150ES is: 33685-201 (black faceplate) 33685-202 (beige faceplate1}) These are referred to as the "ACA version" of the drive. There are _many_ other part numbers for 5150ES drives. If yo2}u have one thatisn't one of the above, it doesn't mean you have an old or an out of rev drive,it just means it's a special 3}version created for a distributor or OEM, or withdifferent default jumper settings. You can order the Wangtek 5150ES OEM 4}Manual from Wangtek. It is part number63045-001 Revision D. There are 5 possible logic boards. Here are the jumper op5}tions for each: Logic assembly #33678 --------------------- (J10) 0 - SCSI unit LSB 1 - SCSI unit 2 - SCSI unit6} MSB K - not documented J32 - Diagnostic test connector, default is not installed E1, F1 - SCSI termination power. E1 7}in = power from drive and to cable, E1 out - power from cable. F1 = terminator power fuse, 1.5A FB. Default is IN. 8}E2 - Chassis ground. E2 in jumpers logic to chassis ground. E2 out isolates through a .33 uFD capacitor. Default is IN9}. E5 - Master oscillator enable. Test only. Must be IN. E20 - Factory test. Must be OUT. RP1, RP2, RP3 - SIP terminator:}s. Default is IN, remove for no termination. Logic assembly #30559 --------------------- HDR1 - Factory testing. Sett;}ing depends on drive. Don't touch. HDR2 - Factory testing. Defaults are pins 15-16, 17-18, 19-20. Don't touch. HDR3 pin 1<} - A-B enables buffered mode. B-C disables. Can be overridden by SCSI Mode Select. HDR3 pin 2, 3 - Default d=}ata format. Set to B-C for a 5150ES. HDR3 pin 4 - parity enable. A-B enables, B-C disables. (J10) 0 - SCSI unit LSB >}1 - SCSI unit 2 - SCSI unit MSB K - not documented E1 - SCSI termination power. E1 in = power from drive and to cable,?} E1 out - power from cable. E2 - Chassis ground. E2 in jumpers logic to chassis ground. E2 out isolates throu@}gh a .33 uFD capacitor. Default is IN. E3 - Master oscillator enable. Test only. Must be IN. E4 - Write test mode. Test oA}nly. Must be OUT. E5 - Write oscillator enable. Test only. Must be IN. E6 - Disable HDR2. Test only. Must be IN. E7 - MB}icrocontroller clock select. In for a 5150ES. E8 - Write precomp select. Set on a per-drive basis. Don't touch. E9 - RAM C}size. Don't touch. E10 - Erase frequency. Don't touch. RP2, RP3 - DIP and SIP terminators. Default is IN, remove for no tD}ermination. Logic assembly #30600 --------------------- HDR1 - Factory testing. Setting depends on drive. Don't touchE}. HDR2 - Write precomp select. Set on a per-drive basis. Don't touch. HDR3 pin 1, 2, 3 - SCSI device address. 1 is LSB, 3F} is MSB. A-B=1, B-C=0 HDR3 pin 4 - Parity enable. IA-B is enabled. HDR3 pin 5, 6 - Default data format. B-C for a 5150ES.G} HDR3 pin 7 - Buffered mode select. A-B is enabled. HDR3 pin 8 - Reserved. Must be OUT. HDR4 - Write frequency select. H}Don't touch. E1 - SCSI termination power. E1 in = power from drive and to cable, E1 out - power from cable. E2 - CI}hassis ground. E2 in jumpers logic to chassis ground. E2 out isolates through a .33 uFD capacitor. Default is IN. E3J} - Hard/soft reset. IN enables hard reset. E4 - Write precomp select. Don't touch. E5 - Clock speed. Don't touch. E6 - K}Tape hole test. Don't touch. Logic assembly #30552 --------------------- HDR1 - Factory testing. Setting depends on dL}rive. Don't touch. HDR2 - Write precomp select. Set on a per-drive basis. Don't touch. HDR3 pin 1, 2, 3 - SCSI device addM}ress. 1 is LSB, 3 is MSB. [Note - HDR3 pins 1-3 are duplicated at another location on the board] HDR3 pin 4 - ParityN} enable. IN is enabled. HDR3 pin 5, 6, 7, 8 - Default data format. 5,5 B-C, 7-8 A-B for a 5150ES. HDR4 - Write frequency O}select. Don't touch. E1 - SCSI termination power. E1 in = power from drive and to cable, E1 out - power from cable.P} E2 - Chassis ground. E2 in jumpers logic to chassis ground. E2 out isolates through a .33 uFD capacitor. Default is Q}IN. E3 - Hard/soft reset. IN enables hard reset. E4 - Write precomp select. Don't touch. E5 - Clock speed. Don't touch.R} E6 - Tape hole test. Don't touch. Logic assembly #30427 --------------------- HDR1 - Factory testing. Setting depeS}nds on drive. Don't touch. HDR2 - Write precomp select. Set on a per-drive basis. Don't touch. HDR3 pin 1, 2, 3 - SCSI deT}vice address. 1 is LSB, 3 is MSB. A-B=1, B-C=0 HDR3 pin 4 - Parity enable. IA-B is enabled. HDR3 pin 5, 6, 7, 8 - DefaultU} data format. 5,5 B-C, 7-8 A-B for a 5150ES. E1, E3 - Factory test. Must be IN. E2 - SCSI termination power. E2 in = poweV}r from drive and to cable, E2 out - power from cable. E4 - Chassis ground. E4 in jumpers logic to chassis ground. E4W} out isolates through a .33 uFD capacitor. Default is IN. Firmware - There are many flavors of firmware. I have seeX}n the followingparts: 24115-xxx 24144-xxx 21158-xxx the -xxx suffix changes as the firmware is updated. According Y}to the folksI spoke to at Wangtek, the standard firmware is the 21158. The latest versionas of this writing is 21158-007. AZ}ll of these will work with the Adaptec andGTAK. The firmware options (as returned by a SCSI Identify) are on the end of t[}heproduct string, which is "WANGTEK 5150ES SCSI ES41C560 AFD QFA STD" for the21158-007 firmware. The 3-letter codes have th\}e following meaning: AFD - Automatic Format Detection - the drive will recognize the format (suchas QIC-24, QIC-120, or ]}QIC-150) that the tape was written in. QFA - Quick File Access - the ability to rapidly locate a tape block, andto imple^}ment the "position to block" and "report block" SCSI commands.This is compatible with the Tandberg implementation. STD -_} Standard feature set.====QUESTION: What is CAM?ANSWER From: ctjones@bnr.ca (Clifton Jones)====Common Access Method.`}It is a proposed ANSI standard to make it easier to program SCSI applicationsby encapsulating the SCSI functions into a sta}andardized calling convention.ANSWER From: landis@sugs.tware.com (Hale Landis)====You may be able to get the CAM spec(s)b} from the SCSI BBS====QUESTION: What is FPT (Termination)?ANSWER From: jvincent@bnr.ca (John Vincent)====FPT is acc}tually really simple, I wish I had thought of it. What it does is use diode clamps to eliminate over and undershoot. The "trd}ick" isthat instead of clamping to +5 and GND they clamp to the output of two regulated voltages. This allows the clamping e}diodes to turn on earlierand is therefore better at eliminating overshoot and undershoot. The blockdiagram for a FPTed signf}al is below. The resistor value is probably in the 120 to 130 ohm range. The actual output voltages of the regulators may nog}tbe exaclty as I have shown them but ideally they are matched to the diode characteristics so that conduction occurs when th}he signal voltage is greater than 3.0 V or less than 0.5 V. +--------------- TERMPWR | ____|_i}___ | | | Vreg 1 |-------*-------------------------*--------------- 3.? V |________| | j} | | | | | k} | \ +------------* / pullup resistor | l} | \ | | / | ____|___ m} | | | | | | | Vreg 2 |----------*----------|--------------- n}3.0 V | |________| | | | --+-- | | o} / \ | +-----------+ /___\ | | | p} | | | | terminated | *-------q}---*------------- signal | | | | |r} --+-- | / \ | /___\ | s} | ___|____ | | | | t} | Vreg 3 |----------*------------------------- 1.0 V (?) |________|====QUESTION: What is Active Teu}rmination?ANSWER From: eric@telebit.com (Eric Smith) and brent@auspex.com (Brent R. Largent)====An active termiv}nator actually has one or more voltage regulators to producethe termination voltage, rather than using resistor voltage diviw}ders.This is a passive terminator:TERMPWR ------/\/\/\/------+------/\/\/\/----- GND x} | | SCSI signalNotice that the termination voltage is varies y}with the voltage on theTERMPWR line. One voltage divider (two resistors) is used for each SCSIsignal.An active terminatz}or looks more like this (supply filter caps omitted): +-----------+TERMPWR -----| in out |------+------{}/\/\/\/-------SCSI signal | gnd | | +-----------+ | | |} +------/\/\/\/-------SCSI signal | |GND ---------------+ | }} +------/\/\/\/-------SCSI signal | et~}c.Assuming that the TERMPWR voltage doesn't drop below the desired terminationvoltage (plus the regulator's minimum drop),} the SCSI signals will alwaysbe terminated to the correct voltage level.Several vendors have started making SCSI active te}rminator chips,which contain the regulator and the resistors including DallasSemiconductor, Unitrode Integrated Circuits an}d Motorola====QUESTION: Why Is Active Termination Better?ANSWER brent@auspex.com (Brent R. Largent)====Typical pas}ive terminators (resistors) fluctuate directly in relation to the TERM Power Voltage. Usually terminating resistors will suf}fice over short distances,like 2-3 feet, but for longer distances active termination is a real advantage. Itreduces noise.} Active Termination provide numerous advantages:- A logic bit can disconnect the termination- Provides Negative Clamping o}n all signal lines- Regulated termination voltage- SCSI-2 spec recommends active termination on both ends of the scsi cable}.- Improved Resistance tolerences (from 1% to about 3%)====QUESTION: Why is SCSI more expensive than IDE?ANSWER From:} landis@sugs.tware.com (Hale Landis)====In a typical single drive PC system, ATA (you call it IDE, theproper name is ATA)} is faster than any SCSI. This is because ofthe 1 to 2 millisecond command overhead of a SCSI host adaptervs. the 100 to 3}00 microsecond command overhead of an ATA drive.Also, ATA transfers data 16-bits at a time from the drivedirectly to/from t}he system bus. Compare this to SCSI whichtransfers data 8-bits at a time between the host adapter and thedrive. The host }adapter may be able to transfer data 16-bits ata time to the system bus.Of course you could go to Fast SCSI or Wide SCSI b}ut that costsa whole bunch more!But then you asked about cost.The real reason SCSI costs more has to do with production }volume.There are about 120,000 drives made per day on this planet. 85%of those drives are ATA. The remainder are SCSI, IPI}, SMD and afew other strange interfaces. The actual percent that are SCSIis falling at a very very slow rate. Without the} productionvolume, componet prices are higher, therefor drive prices arehigher.And then you must add in the host adapter }cost. Compare $15 forATA vs. $50 for a simple SCSI host adapter. But you probablywant a higher quality SCSI host adapter} so plan on spending $100to $500 for one.You figure out how to get people to buy more SCSI drives, say50,000 per day, and} maybe the prices will come down to ATA pricelevels. Plus you could probably get a very good marketing job atany of the di}sk drive companies! Of course, each day more andmore people are discovering the performance advantage of ATA soyour job ma}y not be as easy as you would like.====QUESTION: What is Plug and Play SCSI?ANSWER: leefi@microsoft.com (Lee Fisher) (Up}dated Dec 7 1993)====Plug and Play is the name of a technology that lets PC hardware andattached devices work together au}tomatically. A user can simply attach anew device ("plug it in") and begin working ("begin playing"). This shouldbe possibl}e even while the computer is running, without restarting it.Plug and Play technology is implemented in hardware, in operatin}g systemssuch as Microsoft Windows, and in supporting software such as drivers andBIOS.With Plug and Play technology, use}rs can easily add new capabilities totheir PCs, such as sound or fax, without having to concern themselves withtechnical de}tails or encountering problems. For users of mobile PCs (whoare frequently changing their configurations with docking statio}ns,intermittent network connections, etc.) Plug and Play technology willeasily manage their changing hardware configuration}. For all users, Plugand Play will reduce the time wasted on technical problems and increasetheir productivity and satisfa}ction with PCs.The Plug and Play technology is defined in a series of specificationscovering the major component pieces. T}here are specifications for BIOS,ISA cards, PCI, SCSI, IDE CD-ROM, PCMCIA, drivers, and Microchannel. In anutshell, each ha}rdware device must be able to be uniquely identified, itmust state the services it provides and the resources which it requi}res,it must identify the driver which supports it, and finally it must allowsoftware to configure it.The first Plug and P}lay compliant products are available now, as aredevelopment kits for drivers and hardware. Twenty different Plug and Playpr}oducts were shown at Comdex in November 1993.Specifications:The Plug and Play specifications are now available via anonym}ous ftp at ftp.microsoft.com in the \drg\plug-and-play subdirectory. The files are compressed in .zip format, and are in Mi}crosoft Word format.) Plug and Play ISA files (.\pnpisa\*) errata.zip Clarifications and corrections to pnpisa.doc} isolat.zip MS-DOS testing tool to isloate ISA PnP hardware pnpdos.zip Plug and Play device driver interface speci}fication pnpisa.zip Hardware spec for PnP ISA enhancement vhdlzi.zip Hardware spec for PnP ISA enhancement Plu}g and Play SCSI files (.\scsi_ide\*): pnpscsi.zip Plug and Play SCSI specification proposal scam.zip SCAM (SCSI} Comnfigured Auto-Magically) specification Plug and Play BIOS files (.\bios\*): apmv11.zip Advanced Power managemen}t spec v.1 vios.zip Plug and Play BIOS spec escd1.zip Spec for optional method of storing config info for PnP }BIOSPlayList@Microsoft.COM alias:There is an alias, PlayList@Microsoft.COM, which you can email and get ona Microsoft ma}iling list related to Plug and Play, where the HardwareVendor Relations Group (HVRG) will mail out new specifications,annou}ncements, information on workshops, Windows Hardwware EngineeringConference (WinHEC), etc...Compuserve PlugPlay forum:Th}ere is a forum on Compuserve, GO PLUGPLAY. This forum is the method forsupport, discussions and dialogs about Plug and Play.} In addition, theforum's library contains all of the current specification.Intel Plug and Play kits:If you are intereste}d in Intel's two Plug and Play kits, either "Plug andPlay Kit for MS-DOS and Windows" or "Plug and Play BIOS Enhancements Ki}t",FAX your name and company information to Intel at 1.503.696.1307, andIntel will send you the information.====QUESTIO}N: Where can I get drivers (ASPI and other) for the WD7000 FASST2 host adapter?ANSWER From: Gary Field (garyf@wiis.wang.c}om)====Western Digital stopped producing WD7000 FASST2 cards some time in1990. Future Domain bought the rights to produc}e them and as of early 1994they still do. Columbia Data Products Inc. of Altamonte Springs, Florida stillprovides driver su}pport for the card.Their SST IV driver package provides support for many types of SCSI devicesincluding disks, tapes, and C}DROM. Also included in this package is an ASPImanager driver (equivalent to the Adaptec ASPI4DOS.SYS). I have personallytes}ted this ASPI manager and it works with GNU tar w/ASPI and the Corel CDROMdriver, so most other ASPI stuff should work too. }Versions of SSTASPI.SYSprior to Oct 1993 do NOT work with the above mentioned programs so be sureto check the file date. Th}ere are other useful programs in the package as well.For instance I find the TAPEUTIL program very handy for duplicating tap}es.The price of this package is $99 or $85 as an upgrade of a previous version.A pre-requisite to run this software is that} the adapter card must have aBIOS ROM version of 3.36 or newer. I don't think cards manufactured before1989 or so are compa}tible.Columbia Data Products Inc.1070 B Rainer DrAltamonte Springs, FL 32714 (407) 869-6700====End.====----/* } Gary A. Field - WA1GRC, Wang Labs M/S 019-72B, 1 Industrial Ave Lowell, MA 01851-5161, (508) 967-2514, email: gary}f@wiis.wang.com, EST5EDT A waist is a terrible thing to mind! */ WREPLACEMENT XL/XE POWER SUPPLYby D.F.NeffTHE PROJECTSome time ago, I wrote an article describing how to troubleshoot and} repairyour Atari power supply. At the time that article was written, Atari wasusing a two-tone (coffee and cream) power s}upply which was easily disassembledby removing four screws. As soon as the article was published, Atari switchedto a black}, sealed power supply which was not repairable. To make matterseven worse, this new power supply has a higher failure rate }than the oldtwo-tone power supply. This article provides you with the information youneed to build a new power supply for }your XL or XE. Figure 1 shows theschematic circuit of the new power supply.figure oneTHE ADVANTAGESThe power supply y}ou are going to build will be better than your original fromAtari. First, it's easily repaired if a problem develops. Seco}nd, it'sheavily filtered to help eliminate interference on your monitor screen.Third, it has self contained surge protectio}n to prevent damaging voltagespikes. Fourth, and of special interest to SysOps, the power supply canprovide back-up power }through very short power loses (the type that make yourhouse lights flicker but not go out). Fifth, if someone expresses an} interestin it, I can show you how to modify the circuit to provide battery back-uppower through a lengthy power outage.C}ONSTRUCTIONResist the temptation to use a printed circuit board, and instead, usepoint-to-point wiring on the mounting lug}s to construct this circuit. Beginby marking and drilling all the holes for the mounting screws, cords, andswitches. Next,} mount the transformer at the rear of the box with two 4-40x1/4machine screws and nuts. Install the lug tie strips in conve}nient locationsin the remaining space by using one 4-40x1/4 machine screw and nut for eachstrip. VR1 must be attached to t}he side of the box using a 4-40x1/4 machinescrew and nut. Gently bend the legs of VR1 away from the metal of the box toavo}id the possibility of shorts. Now, construct the circuit as shown inFigure 1. Pay special attention to the polarity of cap}acitors C1, C3, diodesCR1, CR2, ZR1 and the leg numbering sequence of VR1 (see Figure 2). C2 shouldbe attached directly to} legs 2 and 3 of VR1. The leads of C2 should be asshort as possible.Figure twoIf you are replacing an existing Atari pow}er supply, you should cut the twopower cords off of it for use on this new power supply. Otherwise, you mustbuy the plug a}nd cords shown in the parts list. The plug in the list is afive pin plug which is similar to the Atari seven pin plug shown} in Figure 3.Unfortunately, this five pin plug is identical to the Atari video plug foryour monitor signal. If you acciden}tally put the power supply plug in thevideo jack, you will almost certainly damage your computer when you switch thepower o}n. Therefore, you should label both of these plugs at this time toavoid getting them confused with one another later.Cut }the AC plug off of one the Radio Shack two-wire line cords and replace itwith the five-pin plug. Connect one wire to the tw}o pins on one side of theplug and the other wire to the two pins on the opposite side. No connection ismade to the fifth pi}n at the bottom.Figure 3 shows the reassembled plug as if you are looking at the pins and thewire is extending away in fro}nt of you. The wire connected to the pins onyour Left should be connected to SW2 at the point identified with a "+" inFigu}re 1. The wire connected to the pins on the right of Figure 3, should beconnected to the junction of L2 and C5. Do not con}nect this wire to the caseor to a ground. Doing so will disable the interference filter.Figure ThreeTHE CIRCUITM1 is }a Metal Oxide Varistor (MOV) which provides the surge protection. Itworks by providing a short circuit to excessive voltage}s (such as surges). Anextended period of high voltage will cause the MOV to fail and become apermanent short circuit to pr}otect your computer. This, in turn, will blowfuse F1 to protect your house wiring. If, in the future, you find that F1 has}failed and all replacement fuses also fail quickly, you should suspect that M1is bad and replace it. N1 is a neon pilot li}ght which also contributesslightly to the surge protection.CR1, CR2 and C1 rectify the AC to DC. Your voltmeter should in}dicateapproximately nine volts DC across C1.VR1 is a five-volt regulator. VR1 will get hot and must be attached to theme}tal case to provide a heat sink.ZR1 is a Zener diode which provides over-voltage protection in case VR1 fails.Remember tha}t zener diodes are mounted in reverse polarity compared tostandard diodes. If your voltmeter shows less than three volts ac}ross C3, youprobably have ZR1 installed wrong.C3 is a five-volt storage capacitor which acts like a battery. C1 and C3 wi}llkeep your computer running through those momentary power outages we mentionedearlier. SysOps may want to extend this pow}er back-up capability by addingmore C1's and C3's. Just add the additional capacitors in parallel to theones shown in Figu}re 1. The more you add, the longer your computer will runwithout power. But, keep in mind that for the price of several ex}tracapacitors you could install battery back-up instead.C4, C5, L1, and L2 provide filtering to reduce electrical noise. }SW2 is anoptional momentary switch to provide cold reboots without wear and tear onyour console switch.Reassemble the pow}er supply case, making sure there are no loose wirestouching the case metal. Use your voltmeter to check for five volts DC }acrossthe plug, with polarity as shown in Figure 3. If everything checks out ok,you can plug this new power supply into yo}ur computer and become an Atarianagain.NOTE FROM THE AUTHORThis article and many of my other Atari service/construction }articles are inthe public domain. Any user group may reproduce my articles for free. Iwould appreciate receiving a compli}mentary copy of your newsletter containingmy article. I also welcome your comments and suggestions concerning my Atariarti}cles. You may contact me by writing to: Don Neff, Michigan AtariComputer Enthusiasts, P.O. Box 2785, Southfield, Michigan}, 48037. PARTS LISTItem Description Radio Shack#C1 4700uF Cap. 272-1022C2 0.1uF Tant. 272-1432C}3 0.1F Cap. 276-1440C4,5 47pF Cap. 272-121CR1,2 3 Amp Rect. 276-1141F1 1 Amp Fuse 270-1250L1,2 }100uH Choke 273-102M1 MOV 276-568N1 Neon Pilot 272-712SW1 AC Switch 276-602SW2 Momentary} Sw. 275-619T1 Transformer 273-1511VR1 5 Volt Reg. 276-1770ZR1 Zener Diode 276-561 MISCELLANEOUS}-- 5 Lug Strips 274-688-- Case 270-253-- Console Plug 274-003-- Fuse Holder 270-362-- Li}ne Cords 278-1255-- Machine Nuts 64-3018-- Machine Screws 64-3011-- Strain Relief 278-1636nThe files contained in this ARChive give you the information necessary tobuild a better XL/XE power supply. The article or}iginally appeared in theDecember 1987 issue of Michigan Atari Magazine (MAM). Unfortunately,the figures which accompanied }the article in print are available only inhardcopy format at this time (our kingdom for a Scanner!). If you're luckyenough} to have an Atari user group nearby which has been receiving MAM, youcan get the diagrams from them. If not and you wish to} get copies, pleasesend a SASE to: Unicorn Publications Michigan Atari Magazine 3487 Braeburn Cir}cle Ann Arbor, MI 48108Indicate that you want copies of the Power Supply diagrams and we'll sendthem out to you.} Thanks and enjoy!/