S-C DocuMentor — Applesoft
SAVE S.DEF9
1010 *--------------------------------
1020 * "SCRN(" FUNCTION
1030 *--------------------------------
DEF9- 20 B1 00 1040 SCREEN JSR CHRGET
DEFC- 20 EC F1 1050 JSR PLOTFNS GET COLUMN AND ROW
DEFF- 8A 1060 TXA ROW
DF00- A4 F0 1070 LDY FIRST COLUMN
DF02- 20 71 F8 1080 JSR MON.SCRN GET 4-BIT COLOR THERE
DF05- A8 1090 TAY
DF06- 20 01 E3 1100 JSR SNGFLT CONVERT (Y) TO REAL IN FAC
DF09- 4C B8 DE 1110 JMP CHKCLS REQUIRE ")"
1120 *--------------------------------
1130 * PROCESS UNARY OPERATORS (FUNCTIONS)
1140 *--------------------------------
DF0C- C9 D7 1150 UNARY CMP #TOKEN.SCRN NOT UNARY, DO SPECIAL
DF0E- F0 E9 1160 BEQ SCREEN
DF10- 0A 1170 ASL DOUBLE TOKEN TO GET INDEX
DF11- 48 1180 PHA
DF12- AA 1190 TAX
DF13- 20 B1 00 1200 JSR CHRGET
DF16- E0 CF 1210 CPX #TOKEN.LEFTSTR*2-1 LEFT$, RIGHT$, AND MID$
DF18- 90 20 1220 BCC .1 NOT ONE OF THE STRING FUNCTIONS
DF1A- 20 BB DE 1230 JSR CHKOPN STRING FUNCTION, NEED "("
DF1D- 20 7B DD 1240 JSR FRMEVL EVALUATE EXPRESSION FOR STRING
DF20- 20 BE DE 1250 JSR CHKCOM REQUIRE A COMMA
DF23- 20 6C DD 1260 JSR CHKSTR MAKE SURE EXPRESSION IS A STRING
DF26- 68 1270 PLA
DF27- AA 1280 TAX RETRIEVE ROUTINE POINTER
DF28- A5 A1 1290 LDA VPNT+1 STACK ADDRESS OF STRING
DF2A- 48 1300 PHA
DF2B- A5 A0 1310 LDA VPNT
DF2D- 48 1320 PHA
DF2E- 8A 1330 TXA
DF2F- 48 1340 PHA STACK DOUBLED TOKEN
DF30- 20 F8 E6 1350 JSR GETBYT CONVERT NEXT EXPRESSION TO BYTE IN X-REG
DF33- 68 1360 PLA GET DOUBLED TOKEN OFF STACK
DF34- A8 1370 TAY USE AS INDEX TO BRANCH
DF35- 8A 1380 TXA VALUE OF SECOND PARAMETER
DF36- 48 1390 PHA PUSH 2ND PARAM
DF37- 4C 3F DF 1400 JMP .2 JOIN UNARY FUNCTIONS
DF3A- 20 B2 DE 1410 .1 JSR PARCHK REQUIRE "(EXPRESSION)"
DF3D- 68 1420 PLA
DF3E- A8 1430 TAY INDEX INTO FUNCTION ADDRESS TABLE
DF3F- B9 DC CF 1440 .2 LDA UNFNC-TOKEN.SGN-TOKEN.SGN+$100,Y
DF42- 85 91 1450 STA JMPADRS+1 PREPARE TO JSR TO ADDRESS
DF44- B9 DD CF 1460 LDA UNFNC-TOKEN.SGN-TOKEN.SGN+$101,Y
DF47- 85 92 1470 STA JMPADRS+2
DF49- 20 90 00 1480 JSR JMPADRS DOES NOT RETURN FOR
1490 * CHR$, LEFT$, RIGHT$, OR MID$
DF4C- 4C 6A DD 1500 JMP CHKNUM REQUIRE NUMERIC RESULT
1510 *--------------------------------
DF4F- A5 A5 1520 OR LDA ARG "OR" OPERATOR
DF51- 05 9D 1530 ORA FAC IF RESULT NONZERO, IT IS TRUE
DF53- D0 0B 1540 BNE TRUE
1550 *--------------------------------
DF55- A5 A5 1560 AND LDA ARG "AND" OPERATOR
DF57- F0 04 1570 BEQ FALSE IF EITHER IS ZERO, RESULT IS FALSE
DF59- A5 9D 1580 LDA FAC
DF5B- D0 03 1590 BNE TRUE
1600 *--------------------------------
DF5D- A0 00 1610 FALSE LDY #0 RETURN FAC=0
DF5F- 2C 1620 .HS 2C TRICK
1630 *--------------------------------
DF60- A0 01 1640 TRUE LDY #1 RETURN FAC=1
DF62- 4C 01 E3 1650 JMP SNGFLT
1660 *--------------------------------
1670 * PERFORM RELATIONAL OPERATIONS
1680 *--------------------------------
DF65- 20 6D DD 1690 RELOPS JSR CHKVAL MAKE SURE FAC IS CORRECT TYPE
DF68- B0 13 1700 BCS STRCMP TYPE MATCHES, BRANCH IF STRINGS
DF6A- A5 AA 1710 LDA ARG.SIGN NUMERIC COMPARISON
DF6C- 09 7F 1720 ORA #$7F RE-PACK VALUE IN ARG FOR FCOMP
DF6E- 25 A6 1730 AND ARG+1
DF70- 85 A6 1740 STA ARG+1
DF72- A9 A5 1750 LDA #ARG
DF74- A0 00 1760 LDY /ARG
DF76- 20 B2 EB 1770 JSR FCOMP RETURN A-REG = -1,0,1
DF79- AA 1780 TAX AS ARG <,=,> FAC
DF7A- 4C B0 DF 1790 JMP NUMCMP
1800 *--------------------------------
1810 * STRING COMPARISON
1820 *--------------------------------
DF7D- A9 00 1830 STRCMP LDA #0 SET RESULT TYPE TO NUMERIC
DF7F- 85 11 1840 STA VALTYP
DF81- C6 89 1850 DEC CPRTYP MAKE CPRTYP 0000<=>0
DF83- 20 00 E6 1860 JSR FREFAC
DF86- 85 9D 1870 STA FAC STRING LENGTH
DF88- 86 9E 1880 STX FAC+1
DF8A- 84 9F 1890 STY FAC+2
DF8C- A5 A8 1900 LDA ARG+3
DF8E- A4 A9 1910 LDY ARG+4
DF90- 20 04 E6 1920 JSR FRETMP
DF93- 86 A8 1930 STX ARG+3
DF95- 84 A9 1940 STY ARG+4
DF97- AA 1950 TAX LEN (ARG) STRING
DF98- 38 1960 SEC
DF99- E5 9D 1970 SBC FAC SET X TO SMALLER LEN
DF9B- F0 08 1980 BEQ .1
DF9D- A9 01 1990 LDA #1
DF9F- 90 04 2000 BCC .1
DFA1- A6 9D 2010 LDX FAC
DFA3- A9 FF 2020 LDA #$FF
DFA5- 85 A2 2030 .1 STA FAC.SIGN FLAG WHICH SHORTER
DFA7- A0 FF 2040 LDY #$FF
DFA9- E8 2050 INX
2060 STRCMP.1
DFAA- C8 2070 INY
DFAB- CA 2080 DEX
DFAC- D0 07 2090 BNE STRCMP.2 MORE CHARS IN BOTH STRINGS
DFAE- A6 A2 2100 LDX FAC.SIGN IF = SO FAR, DECIDE BY LENGTH
2110 *--------------------------------
DFB0- 30 0F 2120 NUMCMP BMI CMPDONE
DFB2- 18 2130 CLC
DFB3- 90 0C 2140 BCC CMPDONE ...ALWAYS
2150 *--------------------------------
2160 STRCMP.2
DFB5- B1 A8 2170 LDA (ARG+3),Y
DFB7- D1 9E 2180 CMP (FAC+1),Y
DFB9- F0 EF 2190 BEQ STRCMP.1 SAME, KEEP COMPARING
DFBB- A2 FF 2200 LDX #$FF IN CASE ARG GREATER
DFBD- B0 02 2210 BCS CMPDONE IT IS
DFBF- A2 01 2220 LDX #1 FAC GREATER
2230 *--------------------------------
2240 CMPDONE
DFC1- E8 2250 INX CONVERT FF,0,1 TO 0,1,2
DFC2- 8A 2260 TXA
DFC3- 2A 2270 ROL AND TO 0,2,4 IF C=0, ELSE 1,2,5
DFC4- 25 16 2280 AND CPRMASK 00000<=>
DFC6- F0 02 2290 BEQ .1 IF NO MATCH: FALSE
DFC8- A9 01 2300 LDA #1 AT LEAST ONE MATCH: TRUE
DFCA- 4C 93 EB 2310 .1 JMP FLOAT
2320 *--------------------------------
2330 * "PDL" FUNCTION
2340 * <<< NOTE: ARG<4 IS NOT CHECKED >>>
2350 *--------------------------------
DFCD- 20 FB E6 2360 PDL JSR CONINT GET # IN X
DFD0- 20 1E FB 2370 JSR MON.PREAD READ PADDLE
DFD3- 4C 01 E3 2380 JMP SNGFLT FLOAT RESULT
2390 *--------------------------------
2400 * "DIM" STATEMENT
2410 *--------------------------------
DFD6- 20 BE DE 2420 NXDIM JSR CHKCOM SEPARATED BY COMMAS
DFD9- AA 2430 DIM TAX NON-ZERO, FLAGS PTRGET DIM CALLED
DFDA- 20 E8 DF 2440 JSR PTRGET2 ALLOCATE THE ARRAY
DFDD- 20 B7 00 2450 JSR CHRGOT NEXT CHAR
DFE0- D0 F4 2460 BNE NXDIM NOT END OF STATEMENT
DFE2- 60 2470 RTS
S.DD7B
