O.MATHS

   10PROCheader("+")
   20add%=P%
   30FORo%=0TO3STEP3
   40P%=add%
   50[:OPTo%
   60CPX#stkbot%-2
   70BCSunderflow
   80CLC
   90INX:INX
  100LDAstk%-1,X
  110ADCstk%+1,X
  120STAstk%+1,X
  130LDAstk%,X
  140ADCstk%+2,X
  150STAstk%+2,X
  160RTS
  170.underflow
  180LDA#estku%
  190JMP(svct%)
  200]:NEXTo%
  210PROCheader("d+")
  220dadd%=P%
  230FORo%=0TO3STEP3
  240P%=dadd%
  250[:OPTo%
  260CPX#stkbot%-6
  270BCSunderflow
  280CLC
  290LDAstk%+3,X
  300ADCstk%+7,X
  310STAstk%+7,X
  320LDAstk%+4,X
  330ADCstk%+8,X
  340STAstk%+8,X
  350LDAstk%+1,X
  360ADCstk%+5,X
  370STAstk%+5,X
  380LDAstk%+2,X
  390ADCstk%+6,X
  400STAstk%+6,X
  410INX:INX:INX:INX
  420RTS
  430.underflow
  440LDA#estku%
  450JMP(svct%)
  460]:NEXTo%
  470PROCheader("u*")
  480umul%=P%
  490FORo%=0TO3STEP3
  500P%=umul%
  510[:OPTo%
  520CPX#stkbot%-2
  530BCSunderflow
  540LDAstk%+3,X:STAsc%
  550LDAstk%+4,X:STAsc%+1
  560LDA#&00
  570STAstk%+3,X:STAstk%+4,X
  580LDY#&10
  590.rotate
  600ASLstk%+3,X
  610ROLstk%+4,X
  620ROLstk%+1,X
  630ROLstk%+2,X
  640BCCmodify
  650CLC
  660LDAsc%
  670ADCstk%+3,X
  680STAstk%+3,X
  690LDAsc%+1
  700ADCstk%+4,X
  710STAstk%+4,X
  720BCCmodify
  730INCstk%+1,X
  740BNEmodify
  750INCstk%+2,X
  760.modify
  770DEY
  780BNErotate
  790RTS
  800.underflow
  810LDA#estku%
  820JMP(svct%)
  830]:NEXTo%
  840PROCheader("u/")
  850udiv%=P%
  860FORo%=0TO3STEP3
  870P%=udiv%
  880[:OPTo%
  890CPX#stkbot%-4
  900BCSunderflow
  910LDAstk%+1,X
  920BNEnonzero
  930LDAstk%+2,X
  940BEQdivzero
  950.nonzero
  960LDAstk%+5,X
  970LDYstk%+3,X
  980STYstk%+5,X
  990ASLA
 1000STAstk%+3,X
 1010LDAstk%+6,X
 1020LDYstk%+4,X
 1030STYstk%+6,X
 1040ROLA
 1050STAstk%+4,X
 1060LDA#&10
 1070STAsc%
 1080.rotate
 1090ROLstk%+5,X 
 1100ROLstk%+6,X
 1110SEC
 1120LDAstk%+5,X
 1130SBCstk%+1,X
 1140TAY
 1150LDAstk%+6,X
 1160SBCstk%+2,X
 1170BCCmodify
 1180STYstk%+5,X
 1190STAstk%+6,X
 1200.modify
 1210ROLstk%+3,X
 1220ROLstk%+4,X
 1230DECsc%
 1240BNErotate
 1250INX:INX
 1260RTS
 1270.underflow
 1280LDA#estku%
 1290JMP(svct%)
 1300.divzero
 1310LDA#edzero%
 1320JMP(svct%)
 1330]:NEXTo%
 1340PROCheader("minus")
 1350minus%=P%
 1360FORo%=0TO3STEP3
 1370P%=minus%
 1380[:OPTo%
 1390CPX#stkbot%
 1400BEQunderflow
 1410CLC
 1420LDAstk%+1,X
 1430EOR#&FF
 1440ADC#&01
 1450STAstk%+1,X
 1460LDAstk%+2,X
 1470EOR#&FF
 1480ADC#&00
 1490STAstk%+2,X
 1500RTS
 1510.underflow
 1520LDA#estku%
 1530JMP(svct%)
 1540]:NEXTo%
 1550PROCheader("dminus")
 1560dminus%=P%
 1570FORo%=0TO3STEP3
 1580P%=dminus%
 1590[:OPTo%
 1600CPX#stkbot%-2
 1610BCSunderflow
 1620CLC
 1630LDAstk%+3,X
 1640EOR#&FF
 1650ADC#&01
 1660STAstk%+3,X
 1670LDAstk%+4,X
 1680EOR#&FF
 1690ADC#&00
 1700STAstk%+4,X
 1710LDAstk%+1,X
 1720EOR#&FF
 1730ADC#&00
 1740STAstk%+1,X
 1750LDAstk%+2,X
 1760EOR#&FF
 1770ADC#&00
 1780STAstk%+2,X
 1790RTS
 1800.underflow
 1810LDA#estku%
 1820JMP(svct%)
 1830]:NEXTo%
 1840PROCheader("1+")
 1850oneplus%=P%
 1860FORo%=0TO3STEP3
 1870P%=oneplus%
 1880[:OPTo%
 1890CPX#stkbot%
 1900BEQunderflow
 1910INCstk%+1,X
 1920BNEnooverflow
 1930INCstk%+2,X
 1940.nooverflow
 1950RTS
 1960.underflow
 1970LDA#estku%
 1980JMP(svct%)
 1990]:NEXTo%
 2000PROCheader("1-")
 2010oneminus%=P%
 2020FORo%=0TO3STEP3
 2030P%=oneminus%
 2040[:OPTo%
 2050CPX#stkbot%
 2060BEQunderflow
 2070LDAstk%+1,X
 2080BNEnooverflow
 2090DECstk%+2,X
 2100.nooverflow
 2110DECstk%+1,X
 2120RTS
 2130LDA#estku%
 2140JMP(svct%)
 2150]:NEXTo%
 2160PROCheader("2+")
 2170twoplus%=P%
 2180FORo%=0TO3STEP3
 2190P%=twoplus%
 2200[:OPTo%
 2210CPX#stkbot%
 2220BEQunderflow
 2230CLC
 2240LDAstk%+1,X
 2250ADC#&02
 2260STAstk%+1,X
 2270BCCtwoplusend
 2280INCstk%+2,X
 2290.twoplusend 
 2300RTS
 2310.underflow
 2320LDA#estku%
 2330JMP(svct%)
 2340]:NEXTo%
 2350PROCheader("2-")
 2360twominus%=P%
 2370FORo%=0TO3STEP3
 2380P%=twominus%
 2390[:OPTo%
 2400CPX#stkbot%
 2410BEQunderflow
 2420SEC
 2430LDAstk%+1,X
 2440SBC#&02
 2450STAstk%+1,X
 2460BCStwominusend
 2470DECstk%+2,X
 2480.twominusend
 2490RTS
 2500.underflow
 2510LDA#estku%
 2520JMP(svct%)
 2530]:NEXTo%
 2540PROCheader("min")
 2550min%=P%
 2560FORo%=0TO3STEP3
 2570P%=min%
 2580[:OPTo%
 2590CPX#stkbot%-2
 2600BCSunderflow
 2610SEC
 2620LDAstk%+1,X
 2630SBCstk%+3,X
 2640LDAstk%+2,X
 2650SBCstk%+4,X
 2660BPLminend
 2670LDAstk%+1,X
 2680STAstk%+3,X
 2690LDAstk%+2,X
 2700STAstk%+4,X
 2710.minend
 2720INX:INX
 2730RTS
 2740.underflow
 2750LDA#estku%
 2760JMP(svct%)
 2770]:NEXTo%
 2780PROCheader("max")
 2790max%=P%
 2800FORo%=0TO3STEP3
 2810P%=max%
 2820[:OPTo%
 2830CPX#stkbot%-2
 2840BCSunderflow
 2850SEC
 2860LDAstk%+3,X
 2870SBCstk%+1,X
 2880LDAstk%+4,X
 2890SBCstk%+2,X
 2900BPLmaxend
 2910LDAstk%+1,X
 2920STAstk%+3,X
 2930LDAstk%+2,X
 2940STAstk%+4,X
 2950.maxend
 2960INX:INX
 2970RTS
 2980.underflow
 2990LDA#estku%
 3000JMP(svct%)
 3010]:NEXTo%
 3020PROCheader("+-")
 3030plusminus%=P%
 3040FORo%=0TO3STEP3
 3050P%=plusminus%
 3060[:OPTo%
 3070CPX#stkbot%-2
 3080BCSunderflow
 3090LDAstk%+2,X
 3100ASLA
 3110BCCpmend
 3120CLC
 3130LDAstk%+3,X
 3140EOR#&FF
 3150ADC#&01
 3160STAstk%+3,X
 3170LDAstk%+4,X
 3180EOR#&FF
 3190ADC#&00
 3200STAstk%+4,X
 3210.pmend
 3220INX:INX
 3230RTS
 3240.underflow
 3250LDA#estku%
 3260JMP(svct%)
 3270]:NEXTo%
 3280PROCheader("d+-")
 3290dplusminus%=P%
 3300FORo%=0TO3STEP3
 3310P%=dplusminus%
 3320[:OPTo%
 3330CPX#stkbot%-4
 3340BCSunderflow
 3350LDAstk%+2,X
 3360ASLA
 3370BCCdpmend
 3380CLC
 3390LDAstk%+5,X
 3400EOR#&FF
 3410ADC#&01
 3420STAstk%+5,X
 3430LDAstk%+6,X
 3440EOR#&FF
 3450ADC#&00
 3460STAstk%+6,X
 3470LDAstk%+3,X
 3480EOR#&FF
 3490ADC#&00
 3500STAstk%+3,X
 3510LDAstk%+4,X
 3520EOR#&FF
 3530ADC#&00
 3540STAstk%+4,X
 3550.dpmend
 3560INX:INX
 3570RTS
 3580.underflow
 3590LDA#estku%
 3600JMP(svct%)
 3610]:NEXTo%
 3620PROCheader("s->d")
 3630stod%=P%
 3640FORo%=0TO3STEP3
 3650P%=stod%
 3660[:OPTo%
 3670CPX#stkbot%
 3680BEQunderflow
 3690CPX#stktop%
 3700BEQoverflow
 3710DEX:DEX
 3720LDAstk%+4,X
 3730ASLA
 3740BCCpositive
 3750LDA#&FF
 3760STAstk%+1,X
 3770STAstk%+2,X
 3780RTS
 3790.positive
 3800LDA#&00
 3810STAstk%+1,X
 3820STAstk%+2,X
 3830RTS
 3840.underflow
 3850LDA#estku%
 3860JMP(svct%)
 3870.overflow
 3880LDA#estko%
 3890JMP(svct%)
 3900]:NEXTo%
 3910OSCLI("EXEC E.MATHS")
 3920END
 3930DEFPROCheader(name$)
 3940PRINT:PRINT
 3950PRINT"  *** ";~P%;" nfa '";name$;"'"
 3960LETxhere%=P%
 3970LETspan%=LEN(name$)
 3980?P%=span%
 3990PROCsetbit(7,P%)
 4000LETP%=P%+1
 4010IFspan% > length%THENspan%=length%
 4020FORi%=1TOspan%
 4030?P%=ASC(MID$(name$,i%,1))
 4040LETP%=P%+1
 4050NEXTi%
 4060PRINT"  *** ";~P%;" lfa (";~last%;")"
 4070PROCsetbit(7,P%-1)
 4080PROCpoke(last%,P%)
 4090LETP%=P%+2
 4100LETlast%=xhere%
 4110LETlabel%=label%+1
 4120PRINT:PRINT
 4130ENDPROC
 4140DEFPROCsetbit(bit%,addr%)
 4150?addr%=?addr%OR(2^bit%)
 4160ENDPROC
 4170DEFPROCpoke(val%,addr%)
 4180?addr%=val%MOD256
 4190?(addr%+1)=val%DIV256
 4200ENDPROC
 4210DEFFNliteral(value%):[:OPTo%:JSRlit%:]:PROCpoke(value%,P%):P%=P%+2:=o%