1000     .TITLE "CX85 NUMERIC KEYPAD HANDLER - Mac65 version"
1010     .PAGE "Dissasembled by Rich Andrews, Lockport, Il."
1020 ;
1030 ;There was no copyright notice in the original
1040 ; code but one must assume it is public domain
1050 ;and was probably written by Atari Inc.
1060 ;(no one else would have bothered!)
1070 ;once called by Basic do not call again
1080 ;Call thru basic with a X=USR(32512)
1090 ;
1100     .PAGE "CX-85 EQUATES"
1110 ;******************************
1120 ;System equates used
1130 ;******************************
1140 ATRACT = $4D
1150 VVBLKD = $0224
1160 STRIG0 = $0284
1170 STRIG1 = $0285
1180 CH  =   $02FC
1190 ALLPOT = $D208
1200 PORTA = $D300
1210 SETVBV = $E45C
1220 XITVBV = $E462
1230 ;
1240 ;*****************************
1250 ;End of system equates
1260 ;*****************************
1270 ;The following is the keycode
1280 ;equates which are from CH. As
1290 ;per the Atari hardware manual.
1300 ;*****************************
1310 ;
1320 ;
1330 ESC =   $1C
1340 SPC =   $21
1350 DEL =   $34
1360 Y   =   $2B
1370 ZERO =  $32
1380 ONE =   $1F
1390 TWO =   $1E
1400 THREE = $1A
1410 FOUR =  $18
1420 FIVE =  $1D
1430 SIX =   $1B
1440 SEVEN = $33
1450 EIGHT = $35
1460 NINE =  $30
1470 PERIOD = $22
1480 MINUS = $0E
1490 CR  =   $0C
1500 ;
1510     .PAGE "CX-85 HANDLER INSTALLATION ROUTINE"
1520 ;******************************
1530 ;This is the start of the installation routine
1540 ;******************************
1550 ;
1560 ;
1570     .ORG $7F00  ;Start code just below GR.0 screen.
1580     PLA         ;This routine is to be called by basic hence the PLA
1590 ;Remove the PLA instruction for a stand alone file
1600     LDA VVBLKD  ;Call with X=USR(32512)
1610 ;The installation routine could also be a M/L string with the rest
1620 ;of the code previously loaded in via DOS.
1630     STA EXIT+1
1640     LDA VVBLKD+1
1650     STA EXIT+2
1660     LDY # <VBICODE
1670     LDX # >VBICODE
1680     LDA #$07    ;Command to reset vbi pointers.
1690     JSR SETVBV  ;Install vbi routine into interrupt chain.
1700     RTS         ;Return to caller.
1710     .PAGE "CX85 HANDLER LOOKUP TABLE"
1720 ;******************************
1730 LOOKUP ;        This is the lookup table.  This portion can be located
1740 ;in a different area in memory than the Main routine or the
1750 ;installation routine.
1760 ;******************************
1770     .BYTE $0C,ESC
1780     .BYTE $14,SPC,$10,DEL,$18,Y
1790     .BYTE $1C,ZERO,$19,ONE,$1A,TWO
1800     .BYTE $1B,THREE,$11,FOUR,$12
1810     .BYTE FIVE,$13,SIX,$15,SEVEN
1820     .BYTE $16,EIGHT,$17,NINE,$1D
1830     .BYTE PERIOD,$1F,MINUS,$1E
1840     .BYTE CR
1850     BRK         ;End of table delimiter
1860 ;*****************************
1870 ;By changing the table one could define
1880 ;the keys on the CX85 to mean anything!
1890 ;How about some new functions to be accessed
1900 ;through a wedge of some sort?  Terminal
1910 ;program phone dialer?  Maybe a bookkeeping
1920 ;program? As long as it is a printable
1930 ;character it will work. Rich A.
1940     .PAGE "CX-85 HANDLER MAIN VBI ROUTINE"
1950 ;*****************************
1960 ;The vbi routine starts here.
1970 ;*****************************
1980 ;This portion can be located anywhere in memory.
1990 ;*****************************
2000 VBICODE
2010     LDA STRIG1  ;trigger pressed?
2020     BNE SET2BYE ;no-go clr buffer #2+exit.
2030     LDA #$00
2040     STA ATRACT  ;kill attract mode
2050     LDA PORTA   ;lets get some bits
2060     LSR A       ;divide by 2
2070     LSR A       ;divide it again
2080     LSR A       ;ditto
2090     LSR A       ;one more time (Sam?)
2100     STA BUFR1   ;now stuff it in buffer 1
2110     LDA ALLPOT  ;read all the pot lines
2120     AND #$08    ;if it is >=8,then make it 0
2130     EOR #$08    ;if it is <8 then make it 8
2140     ASL A       ;times 2
2150     ORA BUFR1
2160     LDY #$00
2170 ;*******************************
2180 FINDIT
2190     CMP LOOKUP,Y
2200     BEQ FOUND   ;found the code
2210     INY 
2220     INY 
2230     LDX LOOKUP,Y
2240     BEQ EXIT
2250     BNE FINDIT
2260 ;******************************
2270 FOUND
2280     TAX 
2290     INY 
2300     LDA LOOKUP,Y
2310     CMP BUFR2
2320     BEQ PUTCHR
2330     STA BUFR2
2340     STA CH
2350     LDA #$30
2360     STA BUFR3
2370     BNE EXIT    ;always exit
2380 ;******************************
2390 SET2BYE
2400     LDA #$C0    ;when trig1 is not pressed
2410     STA BUFR2   ;read will come back with $C0
2420     BNE EXIT    ;always exit
2430 ;******************************
2440 PUTCHR
2450     LDX BUFR3
2460     DEX 
2470     BNE SET3BYE
2480     STA CH
2490     LDA #$06
2500     STA BUFR3
2510     BNE EXIT
2520 ;*********************
2530 SET3BYE
2540     STX BUFR3
2550 ;*********************
2560 EXIT
2570     JMP XITVBV  ;see you next vbi
2580 ;*********************
2590 BUFR1
2600     .DS 1       ;reserve 1 byte
2610 ;*********************
2620 BUFR2
2630     .DS 1       ;reserve 1 byte
2640 ;*********************
2650 BUFR3
2660     .DS 1       ;reserve 1 byte
2670 ;*********************
2680     .END 
2690 ;The original key layout is as
2700 ;follows
2710 ;-----------------------
2720 ; esc                  |
2730 ;       7 8 9    -     |
2740 ;  N    4 5 6    r     |
2750 ;<del>  1 2 3    e     |
2760 ;  Y     0  .    t     |
2770 ;                      |
2780 ;-----------------------
2790 ; <eof>