þþ·èX;SAVE #D2:DUPSIO.M65òAREV A SIO PATCHAü4X; **** SIO INTERRUPT SERVICE ROUTINES ****X;X;9X; EQUATES FOR INTERRUPT ROUTINES MOVED FROM SIO$X;.X; ZERO PAGE8X;B1†BUFRLO2;;POINTER TO BYTE TO SEND OR RECEIVEL †BUFRHI3V2†BFENLO4;;POINTER TO BYTE AFTER END OF BUFFER` †BFENHI5j/†CHKSUM1;;LOC TO STORE DATA FRAME CHECKSUMt+†CHKSNT;;;CHECKSUM SENT FLAG- =FF SENT~8†NOCKSM<;;FLAG NO CHECK SUM TO BE RECEIVED-NOT ZEROˆ/†STATUS0;;HOLD FOR STATUS TO BE PUT IN DCB’0†BUFRFL8;;FLAG-IF FF RECEIVE BUFFER IS FULLœ7†RECVDN9;;FLAG RECEIVE NOT DONE. USED BY WAIT LOOP¦4†POKMSK;;POKEY INTERRUPT MASK SHADOW FOR IRQEN°X;º=X; HARDWARE REGISTERS USED IN SIO INTERRUPT ROUTINESÄX;Î0…SKRES Ò;;SERIAL PORT STATUS RESET ON POKEYØ&†SEROUT Ò;;SERIAL OUTPUT REGISTERâ1…SERIN†SEROUT;;SERIAL PORT INPUT REG ON POKEYì,…IRQENÒ;;IRQ INTERRUPT ENABLE ON POKEYö/†SKSTATÒ;;SERIAL PORT STATUS REG ON POKEYX; 'X; ERROR CODES RETURNED BY SIOX;%†FRMERRŒ;;FRAMING ERROR ON INPUT(3†OVRRUNŽ;;DATA FRAME OVER RUN-BIT D5 IN SKSTAT2(†CHKERR;;DATA FRAME CHECKSUM ERROR<FHX; **** INTERRUPT SERVICE ROUTINE TO OUTPUT DATA NEEDED ****PX;ZX;dX;n@X; IT UPDATES THE BYTE TO PUT ON SERIAL I/O BUS POINTERxGX; UNTIL END OF BUFFER. AFTER EACH UPDATE OF THE PTR ADDS THE‚IX; VALUE OF THE BYTE TO THE CHECKSUM. OUTPUTS THE CHECKSUM WHENŒKX; PTR EQUALS THE END OF BUFFER PTR (POINTS TO BYTE AFTER BUFFER).–JX; RETURNS TO THIS ROUTINE AFTER CHECKSUM PASSED AND RESETS POKEY IX; INTERRUPT REG TO HAVE THE TRANSMIT DONE ROUTINE CALLED TO ENDª(X; WAIT LOOP (SEE SIO LISTING).´X;¾X; K.B. 6/10/80ÈX;Ò †ISRODNC;;SAVE Y REG ON STACKÜ5æX;ð#†BUFRLOú'H†NOWRP0;;INCREMENT PTR TO NEXT BYTE#†BUFRHI;;TO SENDX;,X; PATCH TO ROUTINE - CHANGED CHECK"X;,1†NOWRP0Q†BUFRLO;;CHECK IF PTR IS WITHIN BUFFER6+R†BFENLO;;DO A DOUBLE PRECISION SUBTRACT@Q†BUFRHIJS†BFENHIT3D†NOTEND;;BRANCH IF (BUFR) < (BFEN)-MORE TO SEND^X;h*Q†CHKSNT;;TEST IF CHECKSUM ALREADY SENTr#H†RELONE;;BRANCH IF ALREADY SENT|X;†&X; SEND CHECKSUM AND SET FLAGX;šQ†CHKSUM¤+P†SEROUT;;PUT CHECKSUM IN SERIAL OUT REG®"†CHKSNT;;SET FLAG TO FF HEX¸H†CHKDON;;RETURNÂX;ÌJX; AFTER CHECKSUM SENT AND CAUSE NEXT INTERRUPT THEN CHANGE POKEYÖKX; MASK TO ENABLE TRANSMIT DONE INTERRUPT AND TERMINATE WAIT LOOP.àX;ê"†RELONEQ†POKMSK;;GET POKEY MASKôL>;;OR IN ENABLEþP†POKMSK!P…IRQEN;;ENABLE THE INTERRUPTSX;#X; RESTORE REGS AND RETURN&X;0†CHKDON7:?;;RESTORE Y REGD57;;RESTORE A REG SAVED IN OS IRQ INTERRUPT HANDLERN9XX;b=X; MORE TO SEND. SEND NEXT BYTE POINTED AT BY BUFR.lX;v†NOTEND%>€Q@†BUFRLO7;;GET NEXT BYTEŠ"P†SEROUT;;PUT IN SERIAL OUT REG”X;ž,¨!O†CHKSUM;;ADD BYTE TO CHECKSUM²O>¼P†CHKSUMÆX;Ð-!†CHKDON;;GO RETURN AND WAIT FOR NEXT BYTEÚX;ä9X; ******** END OF OUT SERVICE ROUTINE ********îøDX; **** SERIAL INPUT READY INTERRUPT SERVICE ROUTINE ****X;X;X; FX; AFTER SERIAL RECEIVE IS ENABLED ROUTINE IS USED TO COLLECT*CX; BYTES FROM THE SERIAL INPUT REG AND PUT THEM IN BUFFER.4EX; WILL STOP WHEN BUFFER IS FULL. IF A CHECKSUM IS EXPECTED>EX; ROUTINE WILL MARK BUFFER FULL AND CONTINUE. WHEN CHECKSUMHBX; RECEIVED IT WILL CHECK IF = TO CHECKSUM IT WAS MAKING.R7X; WILL STORE ERRORS FOUND IN STATUS LOCATION.\X;fLX; THE IRQ INTERRUPT HANDLER IN THE OS PUSHES THE USER'S A REGISTERp7X; ONTO THE STACK BEFORE CALLING THIS ROUTINE.zX;„X; K.B. 6/11/80ŽX;˜ †ISRSIRC;;SAVE Y REG ON STACK¢5¬X;¶0X; GET STATUS FROM POKEY THEN RESET IT.ÀX;ÊQ†SKSTATÔ'P…SKRES;;IGNORES VALUE- JUST STROBEDÞX;èX; CHECK FOR ERRORSòX;ü*G†NTFRAM;;BIT 8 SET IF NO FRAMING ERROR %>†FRMERR #'†STATUS;;SET FRAME ERROR STATUS X;$ 2†NTFRAMM> ;;IF BIT 5 CLEAR THEN FRAME OVER RUN. "H†NTOVRN;;BRANCH IF NO OVER RUN8 %>†OVRRUNB *'†STATUS;;ELSE SET OVERRUN ERROR STATUSL X;V HX; CHECK IF BUFFER FULL AND THIS IS A CHECKSUM. IF IT IS, THEN` )X; CHECK IF DATA SENT WAS VALID.j X;t 3†NTOVRNQ†BUFRFL;;TEST FOR BUFFER FULL (NOT ZERO)~ 0F†NOTYET;;IF ZERO THEN NOT YET, THIS IS DATA.ˆ !Q…SERIN;;ELSE THIS IS CHECKSUM’ R†CHKSUM;;ARE THEY EQUAL?œ F†SRETRN;;YES,THEN RETURN¦ -%>†CHKERR;;ELSE SET CHECK SUM ERROR STATUS° '†STATUSº X;Ä -X; SET RECEIVE DONE TO END WAIT LOOPÎ X;Ø †SRETRNQ>ÿ;;DONE VALUEâ P†RECVDNì X;ö #X; RESTORE REGS AND RETURN X; †SUSUAL7 ?;;RESTORE Y REG 7;;RESTORE A REG( 92 X;< LX; IF BYTE IS DATA, THEN GET HERE. PUT BYTE IN BUFFER AND CHECK IFF X; AT END OF BUFFER.P X;Z †NOTYETQ…SERIN;;GET DATA BYTEd %>n %P@†BUFRLO7;;STORE IT IN THE BUFFERx X;‚ ,Œ &O†CHKSUM;;ADD DATA BYTE TO CHECKSUM– O> P†CHKSUMª X;´ *#†BUFRLO;;INCREMENT POINTER TO LOCATION¾ H†NTWRP1;;FOR NEXT BYTE INPUTÈ #†BUFRHIÒ X;Ü 9X; THE PATCH CHANGED THE TEST FOR END OF BUFFERæ X;ð 0†NTWRP1Q†BUFRLO;;DO DOUBLE PRECISION SUBTRACTú R†BFENLOQ†BUFRHI"S†BFENHI;;CARRY CLEAR IF BORROW:D†SUSUAL;;BRANCH IF (BUFR) < (BFEN)-WITHIN BUFFER LIMIT"X;,7X; DONE WITH DATA. SEE IF CHECKSUM TO BE SENT6X;@&Q†NOCKSM;;IF = ZERO THEN A CHECKSUMJF„GOON;;WILL FOLLOW THE DATATX;^#Q>;;ELSE NO CHECKSUM TO FOLLOWh#P†NOCKSM;;CLEAR NO CHECKSUM FLAGr/F†SRETRN;;RETURN AFTER SET RECEIVE DONE FLAG|X;†4X; SET BUFFER FULL AND THEN GO GET CHECKSUMX;š,„GOON"†BUFRFL;;SET BUFFER FULL FLAG TO FF¤H†SUSUAL;;GO RETURN®X;¸KX; ******** END OF RECEIVE SERIAL INPUT INTERRUPT ROUTINE ********Â…MDEND êô/ …MDEND;;SET END ADDR IN FMS PAST RES DUP SOþ>X; ;BUFFERS DON'T CLOBBER IT.„STAK