goapple2/source/applesoft/S.E597
2014-05-09 17:59:16 -07:00

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1010 *--------------------------------
1020 * CONCATENATE TWO STRINGS
1030 *--------------------------------
1040 CAT LDA FAC+4 SAVE ADDRESS OF FIRST DESCRIPTOR
1050 PHA
1060 LDA FAC+3
1070 PHA
1080 JSR FRM.ELEMENT GET SECOND STRING ELEMENT
1090 JSR CHKSTR MUST BE A STRING
1100 PLA RECOVER ADDRES OF 1ST DESCRIPTOR
1110 STA STRNG1
1120 PLA
1130 STA STRNG1+1
1140 LDY #0
1150 LDA (STRNG1),Y ADD LENGTHS, GET CONCATENATED SIZE
1160 CLC
1170 ADC (FAC+3),Y
1180 BCC .1 OK IF < $100
1190 LDX #ERR.STRLONG
1200 JMP ERROR
1210 .1 JSR STRINI GET SPACE FOR CONCATENATED STRINGS
1220 JSR MOVINS MOVE 1ST STRING
1230 LDA DSCPTR
1240 LDY DSCPTR+1
1250 JSR FRETMP
1260 JSR MOVSTR.1 MOVE 2ND STRING
1270 LDA STRNG1
1280 LDY STRNG1+1
1290 JSR FRETMP
1300 JSR PUTNEW SET UP DESCRIPTOR
1310 JMP FRMEVL.2 FINISH EXPRESSION
1320 *--------------------------------
1330 * GET STRING DESCRIPTOR POINTED AT BY (STRNG1)
1340 * AND MOVE DESCRIBED STRING TO (FRESPC)
1350 *--------------------------------
1360 MOVINS LDY #0
1370 LDA (STRNG1),Y
1380 PHA LENGTH
1390 INY
1400 LDA (STRNG1),Y
1410 TAX PUT STRING POINTER IN X,Y
1420 INY
1430 LDA (STRNG1),Y
1440 TAY
1450 PLA RETRIEVE LENGTH
1460 *--------------------------------
1470 * MOVE STRING AT (Y,X) WITH LENGTH (A)
1480 * TO DESTINATION WHOSE ADDRESS IS IN FRESPC,FRESPC+1
1490 *--------------------------------
1500 MOVSTR STX INDEX PUT POINTER IN INDEX
1510 STY INDEX+1
1520 MOVSTR.1
1530 TAY LENGTH TO Y-REG
1540 BEQ .2 IF LENGTH IS ZERO, FINISHED
1550 PHA SAVE LENGTH ON STACK
1560 .1 DEY MOVE BYTES FROM (INDEX) TO (FRESPC)
1570 LDA (INDEX),Y
1580 STA (FRESPC),Y
1590 TYA TEST IF ANY LEFT TO MOVE
1600 BNE .1 YES, KEEP MOVING
1610 PLA NO, FINISHED. GET LENGTH
1620 .2 CLC AND ADD TO FRESPC, SO
1630 ADC FRESPC FRESPC POINTS TO NEXT HIGHER
1640 STA FRESPC BYTE. (USED BY CONCATENATION)
1650 BCC .3
1660 INC FRESPC+1
1670 .3 RTS
1680 *--------------------------------
1690 * IF (FAC) IS A TEMPORARY STRING, RELEASE DESCRIPTOR
1700 *--------------------------------
1710 FRESTR JSR CHKSTR LAST RESULT A STRING?
1720 *--------------------------------
1730 * IF STRING DESCRIPTOR POINTED TO BY FAC+3,4 IS
1740 * A TEMPORARY STRING, RELEASE IT.
1750 *--------------------------------
1760 FREFAC LDA FAC+3 GET DESCRIPTOR POINTER
1770 LDY FAC+4
1780 *--------------------------------
1790 * IF STRING DESCRIPTOR WHOSE ADDRESS IS IN Y,A IS
1800 * A TEMPORARY STRING, RELEASE IT.
1810 *--------------------------------
1820 FRETMP STA INDEX SAVE THE ADDRESS OF THE DESCRIPTOR
1830 STY INDEX+1
1840 JSR FRETMS FREE DESCRIPTOR IF IT IS TEMPORARY
1850 PHP REMEMBER IF TEMP
1860 LDY #0 POINT AT LENGTH OF STRING
1870 LDA (INDEX),Y
1880 PHA SAVE LENGTH ON STACK
1890 INY
1900 LDA (INDEX),Y
1910 TAX GET ADDRESS OF STRING IN Y,X
1920 INY
1930 LDA (INDEX),Y
1940 TAY
1950 PLA LENGTH IN A
1960 PLP RETRIEVE STATUS, Z=1 IF TEMP
1970 BNE .2 NOT A TEMPORARY STRING
1980 CPY FRETOP+1 IS IT THE LOWEST STRING?
1990 BNE .2 NO
2000 CPX FRETOP
2010 BNE .2 NO
2020 PHA YES, PUSH LENGTH AGAIN
2030 CLC RECOVER THE SPACE USED BY
2040 ADC FRETOP THE STRING
2050 STA FRETOP
2060 BCC .1
2070 INC FRETOP+1
2080 .1 PLA RETRIEVE LENGTH AGAIN
2090 .2 STX INDEX ADDRESS OF STRING IN Y,X
2100 STY INDEX+1 LENGTH OF STRING IN A-REG
2110 RTS
2120 *--------------------------------
2130 * RELEASE TEMPORARY DESCRIPTOR IF Y,A = LASTPT
2140 *--------------------------------
2150 FRETMS CPY LASTPT+1 COMPARE Y,A TO LATEST TEMP
2160 BNE .1 NOT SAME ONE, CANNOT RELEASE
2170 CMP LASTPT
2180 BNE .1 NOT SAME ONE, CANNOT RELEASE
2190 STA TEMPPT UPDATE TEMPT FOR NEXT TEMP
2200 SBC #3 BACK OFF LASTPT
2210 STA LASTPT
2220 LDY #0 NOW Y,A POINTS TO TOP TEMP
2230 .1 RTS Z=0 IF NOT TEMP, Z=1 IF TEMP
2240 *--------------------------------
2250 * "CHR$" FUNCTION
2260 *--------------------------------
2270 CHRSTR JSR CONINT CONVERT ARGUMENT TO BYTE IN X
2280 TXA
2290 PHA SAVE IT
2300 LDA #1 GET SPACE FOR STRING OF LENGTH 1
2310 JSR STRSPA
2320 PLA RECALL THE CHARACTER
2330 LDY #0 PUT IN STRING
2340 STA (FAC+1),Y
2350 PLA POP RETURN ADDRESS
2360 PLA
2370 JMP PUTNEW MAKE IT A TEMPORARY STRING
2380 *--------------------------------
2390 * "LEFT$" FUNCTION
2400 *--------------------------------
2410 LEFTSTR
2420 JSR SUBSTRING.SETUP
2430 CMP (DSCPTR),Y COMPARE 1ST PARAMETER TO LENGTH
2440 TYA Y=A=0
2450 SUBSTRING.1
2460 BCC .1 1ST PARAMETER SMALLER, USE IT
2470 LDA (DSCPTR),Y 1ST IS LONGER, USE STRING LENGTH
2480 TAX IN X-REG
2490 TYA Y=A=0 AGAIN
2500 .1 PHA PUSH LEFT END OF SUBSTRING
2510 SUBSTRING.2
2520 TXA
2530 SUBSTRING.3
2540 PHA PUSH LENGTH OF SUBSTRING
2550 JSR STRSPA MAKE ROOM FOR STRING OF (A) BYTES
2560 LDA DSCPTR RELEASE PARAMETER STRING IF TEMP
2570 LDY DSCPTR+1
2580 JSR FRETMP
2590 PLA GET LENGTH OF SUBSTRING
2600 TAY IN Y-REG
2610 PLA GET LEFT END OF SUBSTRING
2620 CLC ADD TO POINTER TO STRING
2630 ADC INDEX
2640 STA INDEX
2650 BCC .1
2660 INC INDEX+1
2670 .1 TYA LENGTH
2680 JSR MOVSTR.1 COPY STRING INTO SPACE
2690 JMP PUTNEW ADD TO TEMPS
2700 *--------------------------------
2710 * "RIGHT$" FUNCTION
2720 *--------------------------------
2730 RIGHTSTR
2740 JSR SUBSTRING.SETUP
2750 CLC COMPUTE LENGTH-WIDTH OF SUBSTRING
2760 SBC (DSCPTR),Y TO GET STARTING POINT IN STRING
2770 EOR #$FF
2780 JMP SUBSTRING.1 JOIN LEFT$
2790 *--------------------------------
2800 * "MID$" FUNCTION
2810 *--------------------------------
2820 MIDSTR LDA #$FF FLAG WHETHER 2ND PARAMETER
2830 STA FAC+4
2840 JSR CHRGOT SEE IF ")" YET
2850 CMP #')'
2860 BEQ .1 YES, NO 2ND PARAMETER
2870 JSR CHKCOM NO, MUST HAVE COMMA
2880 JSR GETBYT GET 2ND PARAM IN X-REG
2890 .1 JSR SUBSTRING.SETUP
2900 DEX 1ST PARAMETER - 1
2910 TXA
2920 PHA
2930 CLC
2940 LDX #0
2950 SBC (DSCPTR),Y
2960 BCS SUBSTRING.2
2970 EOR #$FF
2980 CMP FAC+4 USE SMALLER OF TWO
2990 BCC SUBSTRING.3
3000 LDA FAC+4
3010 BCS SUBSTRING.3 ...ALWAYS
3020 *--------------------------------
3030 * COMMON SETUP ROUTINE FOR LEFT$, RIGHT$, MID$:
3040 * REQUIRE ")"; POP RETURN ADRS, GET DESCRIPTOR
3050 * ADDRESS, GET 1ST PARAMETER OF COMMAND
3060 *--------------------------------
3070 SUBSTRING.SETUP
3080 JSR CHKCLS REQUIRE ")"
3090 PLA SAVE RETURN ADDRESS
3100 TAY IN Y-REG AND LENGTH
3110 PLA
3120 STA LENGTH
3130 PLA POP PREVIOUS RETURN ADDRESS
3140 PLA (FROM GOROUT).
3150 PLA RETRIEVE 1ST PARAMETER
3160 TAX
3170 PLA GET ADDRESS OF STRING DESCRIPTOR
3180 STA DSCPTR
3190 PLA
3200 STA DSCPTR+1
3210 LDA LENGTH RESTORE RETURN ADDRESS
3220 PHA
3230 TYA
3240 PHA
3250 LDY #0
3260 TXA GET 1ST PARAMETER IN A-REG
3270 BEQ GOIQ ERROR IF 0
3280 RTS
3290 *--------------------------------
3300 * "LEN" FUNCTION
3310 *--------------------------------
3320 LEN JSR GETSTR GET LENTGH IN Y-REG, MAKE FAC NUMERIC
3330 JMP SNGFLT FLOAT Y-REG INTO FAC
3340 *--------------------------------
3350 * IF LAST RESULT IS A TEMPORARY STRING, FREE IT
3360 * MAKE VALTYP NUMERIC, RETURN LENGTH IN Y-REG
3370 *--------------------------------
3380 GETSTR JSR FRESTR IF LAST RESULT IS A STRING, FREE IT
3390 LDX #0 MAKE VALTYP NUMERIC
3400 STX VALTYP
3410 TAY LENGTH OF STRING TO Y-REG
3420 RTS
3430 *--------------------------------
3440 * "ASC" FUNCTION
3450 *--------------------------------
3460 ASC JSR GETSTR GET STRING, GET LENGTH IN Y-REG
3470 BEQ GOIQ ERROR IF LENGTH 0
3480 LDY #0
3490 LDA (INDEX),Y GET 1ST CHAR OF STRING
3500 TAY
3510 JMP SNGFLT FLOAT Y-REG INTO FAC
3520 *--------------------------------
3530 GOIQ JMP IQERR ILLEGAL QUANTITY ERROR
3540 *--------------------------------
3550 * SCAN TO NEXT CHARACTER AND CONVERT EXPRESSION
3560 * TO SINGLE BYTE IN X-REG
3570 *--------------------------------
3580 GTBYTC JSR CHRGET
3590 *--------------------------------
3600 * EVALUATE EXPRESSION AT TXTPTR, AND
3610 * CONVERT IT TO SINGLE BYTE IN X-REG
3620 *--------------------------------
3630 GETBYT JSR FRMNUM
3640 *--------------------------------
3650 * CONVERT (FAC) TO SINGLE BYTE INTEGER IN X-REG
3660 *--------------------------------
3670 CONINT JSR MKINT CONVERT IF IN RANGE -32767 TO +32767
3680 LDX FAC+3 HI-BYTE MUST BE ZERO
3690 BNE GOIQ VALUE > 255, ERROR
3700 LDX FAC+4 VALUE IN X-REG
3710 JMP CHRGOT GET NEXT CHAR IN A-REG
3720 *--------------------------------
3730 * "VAL" FUNCTION
3740 *--------------------------------
3750 VAL JSR GETSTR GET POINTER TO STRING IN INDEX
3760 BNE .1 LENGTH NON-ZERO
3770 JMP ZERO.FAC RETURN 0 IF LENGTH=0
3780 .1 LDX TXTPTR SAVE CURRENT TXTPTR
3790 LDY TXTPTR+1
3800 STX STRNG2
3810 STY STRNG2+1
3820 LDX INDEX
3830 STX TXTPTR POINT TXTPTR TO START OF STRING
3840 CLC
3850 ADC INDEX ADD LENGTH
3860 STA DEST POINT DEST TO END OF STRING + 1
3870 LDX INDEX+1
3880 STX TXTPTR+1
3890 BCC .2
3900 INX
3910 .2 STX DEST+1
3920 LDY #0 SAVE BYTE THAT FOLLOWS STRING
3930 LDA (DEST),Y ON STACK
3940 PHA
3950 LDA #0 AND STORE $00 IN ITS PLACE
3960 STA (DEST),Y
3970 * <<< THAT CAUSES A BUG IF HIMEM = $BFFF, >>>
3980 * <<< BECAUSE STORING $00 AT $C000 IS NO >>>
3990 * <<< USE; $C000 WILL ALWAYS BE LAST CHAR >>>
4000 * <<< TYPED, SO FIN WON'T TERMINATE UNTIL >>>
4010 * <<< IT SEES A ZERO AT $C010! >>>
4020 JSR CHRGOT PRIME THE PUMP
4030 JSR FIN EVALUATE STRING
4040 PLA GET BYTE THAT SHOULD FOLLOW STRING
4050 LDY #0 AND PUT IT BACK
4060 STA (DEST),Y
4070 * RESTORE TXTPTR
4080 *--------------------------------
4090 * COPY STRNG2 INTO TXTPTR
4100 *--------------------------------
4110 POINT LDX STRNG2
4120 LDY STRNG2+1
4130 STX TXTPTR
4140 STY TXTPTR+1
4150 RTS
4160 *--------------------------------
4170 * EVALUATE "EXP1,EXP2"
4180 *
4190 * CONVERT EXP1 TO 16-BIT NUMBER IN LINNUM
4200 * CONVERT EXP2 TO 8-BIT NUMBER IN X-REG
4210 *--------------------------------
4220 GTNUM JSR FRMNUM
4230 JSR GETADR
4240 *--------------------------------
4250 * EVALUATE ",EXPRESSION"
4260 * CONVERT EXPRESSION TO SINGLE BYTE IN X-REG
4270 *--------------------------------
4280 COMBYTE
4290 JSR CHKCOM MUST HAVE COMMA FIRST
4300 JMP GETBYT CONVERT EXPRESSION TO BYTE IN X-REG
4310 *--------------------------------
4320 * CONVERT (FAC) TO A 16-BIT VALUE IN LINNUM
4330 *--------------------------------
4340 GETADR LDA FAC FAC < 2^16?
4350 CMP #$91
4360 BCS GOIQ NO, ILLEGAL QUANTITY
4370 JSR QINT CONVERT TO INTEGER
4380 LDA FAC+3 COPY IT INTO LINNUM
4390 LDY FAC+4
4400 STY LINNUM TO LINNUM
4410 STA LINNUM+1
4420 RTS
4430 *--------------------------------
4440 * "PEEK" FUNCTION
4450 *--------------------------------
4460 PEEK LDA LINNUM SAVE (LINNUM) ON STACK DURING PEEK
4470 PHA
4480 LDA LINNUM+1
4490 PHA
4500 JSR GETADR GET ADDRESS PEEKING AT
4510 LDY #0
4520 LDA (LINNUM),Y TAKE A QUICK LOOK
4530 TAY VALUE IN Y-REG
4540 PLA RESTORE LINNUM FROM STACK
4550 STA LINNUM+1
4560 PLA
4570 STA LINNUM
4580 JMP SNGFLT FLOAT Y-REG INTO FAC
4590 *--------------------------------
4600 * "POKE" STATEMENT
4610 *--------------------------------
4620 POKE JSR GTNUM GET THE ADDRESS AND VALUE
4630 TXA VALUE IN A,
4640 LDY #0
4650 STA (LINNUM),Y STORE IT AWAY,
4660 RTS AND THAT'S ALL FOR TODAY
4670 *--------------------------------
4680 * "WAIT" STATEMENT
4690 *--------------------------------
4700 WAIT JSR GTNUM GET ADDRESS IN LINNUM, MASK IN X
4710 STX FORPNT SAVE MASK
4720 LDX #0
4730 JSR CHRGOT ANOTHER PARAMETER?
4740 BEQ .1 NO, USE $00 FOR EXCLUSIVE-OR
4750 JSR COMBYTE GET XOR-MASK
4760 .1 STX FORPNT+1 SAVE XOR-MASK HERE
4770 LDY #0
4780 .2 LDA (LINNUM),Y GET BYTE AT ADDRESS
4790 EOR FORPNT+1 INVERT SPECIFIED BITS
4800 AND FORPNT SELECT SPECIFIED BITS
4810 BEQ .2 LOOP TILL NOT 0
4820 RTS.10 RTS