1000 SYS999
1010 ;
1020 ;POWER ASSEMBLER (BUDDY)
1030 ;
1040 *= $C800
1050 ;
1060 .MEM
1070 ;
1080 ;------------ FAR-SYS ------------
1090 ;
1100 ;SYSTEM ROUTINES
1110 ;
1120 CHRGET = $0073
1130 CHR(null)T = $0079
1140 CHKCOM = $AEFD
1150 FRMNUM = $AD8A
1160 GETADR = $B7F7
1170 ONEBYT = $B79E
1180 ;
1190 ;---------------------------------
1200 ;
1210 FARSYS  JMP SETUP
1220 FARJSR  JMP RELAY
1230 ;
1240 BANK   .BYTE 0 ;POKE 0-5 HERE
1250 CNFG   .BYTE 0 ;CURRENT CONFIG
1260 MASK   .BYTE 0 ;NEW CONFIG
1270 ;
1280 JUMPER  JMP ($0014)
1290 ;
1300 ;TABLE OF VALUES TO 'AND WITH 6510 PORT
1310 ;
1320 MSKTBL =*
1330 .BYTE 255 ;BANK 0 - NO CHANGE
1340 .BYTE 246 ;BANK 1 - BAS. OUT, KERN & I/O IN
1350 .BYTE 242 ;BANK 2 - BAS. OUT, KERN & CHR. IN
1360 .BYTE 245 ;BANK 3 - BAS. & KERN OUT, I/O IN
1370 .BYTE 241 ;BANK 4 - BAS. & KERN OUT, CHR. IN
1380 .BYTE 244 ;BANK 5 - ALL RAM
1390 ;
1400 ;
1410 SETUP   JSR TWOBYT   ;READ ADDRESS FROM BASIC TEXT
1420 :       LDX BANK
1430 :       CPX #$06
1440 :       BCC OK
1450 BAD     JMP $A8E3    ;DISPLAY 'UNDEF STATEMENT' IF BANK>5
1460 OK      LDA $01
1470 :       STA CNFG
1480 :       AND MSKTBL,X ;MASK BITS APPROPO.
1490 :       STA MASK
1500 ;
1510 :       JSR GETARGS
1520 ;
1530 LONG    JSR ROMSOUT
1540 :       LDA $030F    ;GET SRREG
1550 :       ORA #$04     ;ENSURE NO IRQ WHEN PLP
1560 :       PHA
1570 :       LDA $030C
1580 :       LDX $030D
1590 :       LDY $030E
1600 :       PLP          ;AS PER ABOVE
1610 :       JSR JUMPER   ;GOTO TARGET
1620 ;
1630 ROMSIN  PHP          ;BACK HERE
1640 :       PHA          ;SAVE FLAGS & ACC.
1650 :       LDA CNFG
1660 :       STA $01      ;ROMS IN
1670 :       PLA
1680 :       PLP
1690 :       CLI
1700 :       RTS
1710 ;
1720 ;ROUTINE TO ALLOW 'HIDDEN' CODE TO CALL ROM ROUTINES.
1730 ;ASSUMES ADDRESS IN $14/15, A, X, Y AND SR IN $030C - $030F.
1740 ;ALSO ASSUMES 'CNFG' RESTORES ROMS AND 'MASK' IS VALID
1750 ;
1760 RELAY   LDA CNFG
1770 :       STA $01   ;RESTORE ROM(S)
1780 :       JSR $E136 ;PART OF "SYS". LOADS REGS, JMP ($0014)
1790 :       JSR $E147 ;STORES REGS.
1800 ;
1810 ROMSOUT SEI
1820 :       LDA MASK
1830 :       STA $01
1840 :       RTS
1850 ;
1860 ;LOOK FOR COMMA, GET EXPRESSION 0 - 65535 FROM BASIC TEXT
1870 ;
1880 TWOBYT  JSR CHKCOM
1890 :       JSR FRMNUM ;EVAL EXPRESSION
1900 :       JMP GETADR ;TWO BYTES IN $14/15
1910 ;
1920 ;THIS ROUTINE RETURNS WITH CARRY CLEAR IF END OF STATEMENT OR COMMA
1930 ;FOLLOWED BY COMMA, CARRY SET AND ONE BYTE IN X IF NUM. EXPRESSION.
1940 ;
1950 ;
1960 COMBYT  JSR CHR(null)T  ;CURRENT CHR.
1970 :       BEQ COMEXIT ;END OF STATEMENT
1980 :       JSR CHKCOM  ;LOOK FOR COMMA AND NEXT CHR.
1990 :       CMP #$2C    ;ANOTHER COMMA"?
2000 :       BEQ COMEXIT ;YEAH
2010 :       JSR [145]EBYT  ;NO. [161] [197]UE
2020 :       SEC
2030 :       RTS
2040 COMEXIT CLC
2050 :       RTS
2060 ;
2070 ;ROUTINE [164] [135] A, X, Y, [175] SR
2080 ;[197]UES FROM BASIC TEXT.
2090 ;
2100 [161]ARGS JSR COMBYT ;FIRST PARAM (.A)
2110 :       BCC X[161]   ;JUST A COMMA. [161] [130]
2120 :       STX $030C  ;SAREG
2130 X[161]    JSR COMBYT ;[130] PARAM (.X)
2140 :       BCC Y[161]
2150 :       STX $030D  ;SXREG
2160 Y[161]    JSR COMBYT ;[161] .Y
2170 :       BCC S[161]   ;A[168]HER COMMA"?
2180 :       STX $030E  ;SYREG
2190 SGET    JSR COMBYT ;GET .SR
2200 :       BCC EXREG
2210 :       STX $030F  ;SRREG
2220 EXREG   RTS
2230 ;