; Number conversions routines. ; ; Written by Irmen de Jong (irmen@razorvine.net) - license: GNU GPL 3.0 conv { ; ----- number conversions to decimal strings ---- asmsub ubyte2decimal (ubyte value @A) -> ubyte @Y, ubyte @A, ubyte @X { ; ---- A to decimal string in Y/A/X (100s in Y, 10s in A, 1s in X) %asm {{ ldy #uword2decimal.ASCII_0_OFFSET bne uword2decimal.hex_try200 rts }} } asmsub uword2decimal (uword value @AY) -> ubyte @Y, ubyte @A, ubyte @X { ; ---- convert 16 bit uword in A/Y to decimal ; output in uword2decimal.decTenThousands, decThousands, decHundreds, decTens, decOnes ; (these are terminated by a zero byte so they can be easily printed) ; also returns Y = 100's, A = 10's, X = 1's %asm {{ ;Convert 16 bit Hex to Decimal (0-65535) Rev 2 ;By Omegamatrix Further optimizations by tepples ; routine from http://forums.nesdev.com/viewtopic.php?f=2&t=11341&start=15 ;HexToDec99 ; start in A ; end with A = 10's, decOnes (also in X) ;HexToDec255 ; start in A ; end with Y = 100's, A = 10's, decOnes (also in X) ;HexToDec999 ; start with A = high byte, Y = low byte ; end with Y = 100's, A = 10's, decOnes (also in X) ; requires 1 extra temp register on top of decOnes, could combine ; these two if HexToDec65535 was eliminated... ;HexToDec65535 ; start with A/Y (low/high) as 16 bit value ; end with decTenThousand, decThousand, Y = 100's, A = 10's, decOnes (also in X) ; (irmen: I store Y and A in decHundreds and decTens too, so all of it can be easily printed) ASCII_0_OFFSET = $30 temp = P8ZP_SCRATCH_B1 ; byte in zeropage hexHigh = P8ZP_SCRATCH_W1 ; byte in zeropage hexLow = P8ZP_SCRATCH_W1+1 ; byte in zeropage HexToDec65535; SUBROUTINE sty hexHigh ;3 @9 sta hexLow ;3 @12 tya tax ;2 @14 lsr a ;2 @16 lsr a ;2 @18 integer divide 1024 (result 0-63) cpx #$A7 ;2 @20 account for overflow of multiplying 24 from 43,000 ($A7F8) onward, adc #1 ;2 @22 we can just round it to $A700, and the divide by 1024 is fine... ;at this point we have a number 1-65 that we have to times by 24, ;add to original sum, and Mod 1024 to get a remainder 0-999 sta temp ;3 @25 asl a ;2 @27 adc temp ;3 @30 x3 tay ;2 @32 lsr a ;2 @34 lsr a ;2 @36 lsr a ;2 @38 lsr a ;2 @40 lsr a ;2 @42 tax ;2 @44 tya ;2 @46 asl a ;2 @48 asl a ;2 @50 asl a ;2 @52 clc ;2 @54 adc hexLow ;3 @57 sta hexLow ;3 @60 txa ;2 @62 adc hexHigh ;3 @65 sta hexHigh ;3 @68 ror a ;2 @70 lsr a ;2 @72 tay ;2 @74 integer divide 1,000 (result 0-65) lsr a ;2 @76 split the 1,000 and 10,000 digit tax ;2 @78 lda ShiftedBcdTab,x ;4 @82 tax ;2 @84 rol a ;2 @86 and #$0F ;2 @88 ora #ASCII_0_OFFSET sta decThousands ;3 @91 txa ;2 @93 lsr a ;2 @95 lsr a ;2 @97 lsr a ;2 @99 ora #ASCII_0_OFFSET sta decTenThousands ;3 @102 lda hexLow ;3 @105 cpy temp ;3 @108 bmi _doSubtract ;2³ @110/111 beq _useZero ;2³ @112/113 adc #23 + 24 ;2 @114 _doSubtract sbc #23 ;2 @116 sta hexLow ;3 @119 _useZero lda hexHigh ;3 @122 sbc #0 ;2 @124 Start100s and #$03 ;2 @126 tax ;2 @128 0,1,2,3 cmp #2 ;2 @130 rol a ;2 @132 0,2,5,7 ora #ASCII_0_OFFSET tay ;2 @134 Y = Hundreds digit lda hexLow ;3 @137 adc Mod100Tab,x ;4 @141 adding remainder of 256, 512, and 256+512 (all mod 100) bcs hex_doSub200 ;2³ @143/144 hex_try200 cmp #200 ;2 @145 bcc hex_try100 ;2³ @147/148 hex_doSub200 iny ;2 @149 iny ;2 @151 sbc #200 ;2 @153 hex_try100 cmp #100 ;2 @155 bcc HexToDec99 ;2³ @157/158 iny ;2 @159 sbc #100 ;2 @161 HexToDec99; SUBROUTINE lsr a ;2 @163 tax ;2 @165 lda ShiftedBcdTab,x ;4 @169 tax ;2 @171 rol a ;2 @173 and #$0F ;2 @175 ora #ASCII_0_OFFSET sta decOnes ;3 @178 txa ;2 @180 lsr a ;2 @182 lsr a ;2 @184 lsr a ;2 @186 ora #ASCII_0_OFFSET ; irmen: load X with ones, and store Y and A too, for easy printing afterwards sty decHundreds sta decTens ldx decOnes rts ;6 @192 Y=hundreds, A = tens digit, X=ones digit HexToDec999; SUBROUTINE sty hexLow ;3 @9 jmp Start100s ;3 @12 Mod100Tab .byte 0,56,12,56+12 ShiftedBcdTab .byte $00,$01,$02,$03,$04,$08,$09,$0A,$0B,$0C .byte $10,$11,$12,$13,$14,$18,$19,$1A,$1B,$1C .byte $20,$21,$22,$23,$24,$28,$29,$2A,$2B,$2C .byte $30,$31,$32,$33,$34,$38,$39,$3A,$3B,$3C .byte $40,$41,$42,$43,$44,$48,$49,$4A,$4B,$4C decTenThousands .byte 0 decThousands .byte 0 decHundreds .byte 0 decTens .byte 0 decOnes .byte 0 .byte 0 ; zero-terminate the decimal output string }} } asmsub byte2decimal (byte value @A) -> ubyte @Y, ubyte @A, ubyte @X { ; ---- A (signed byte) to decimal string in Y/A/X (100s in Y, 10s in A, 1s in X) ; note: if the number is negative, you have to deal with the '-' yourself! %asm {{ cmp #0 bpl + eor #255 clc adc #1 + jmp ubyte2decimal }} } asmsub ubyte2hex (ubyte value @A) -> ubyte @A, ubyte @Y { ; ---- A to hex petscii string in AY (first hex char in A, second hex char in Y) %asm {{ stx P8ZP_SCRATCH_REG pha and #$0f tax ldy _hex_digits,x pla lsr a lsr a lsr a lsr a tax lda _hex_digits,x ldx P8ZP_SCRATCH_REG rts _hex_digits .text "0123456789abcdef" ; can probably be reused for other stuff as well }} } asmsub uword2hex (uword value @AY) clobbers(A,Y) { ; ---- convert 16 bit uword in A/Y into 4-character hexadecimal string 'uword2hex.output' (0-terminated) %asm {{ sta P8ZP_SCRATCH_REG tya jsr ubyte2hex sta output sty output+1 lda P8ZP_SCRATCH_REG jsr ubyte2hex sta output+2 sty output+3 rts output .text "0000", $00 ; 0-terminated output buffer (to make printing easier) }} } ; ---- string conversion to numbers ----- asmsub any2uword(str string @AY) clobbers(Y) -> ubyte @A { ; -- parses a string into a 16 bit unsigned number. String may be in decimal, hex or binary format. ; (the latter two require a $ or % prefix to be recognised) ; (any non-digit character will terminate the number string that is parsed) ; returns amount of processed characters in A, and the parsed number will be in cx16.r15. ; if the string was invalid, 0 will be returned in A. %asm {{ pha sta P8ZP_SCRATCH_W1 sty P8ZP_SCRATCH_W1+1 ldy #0 lda (P8ZP_SCRATCH_W1),y ldy P8ZP_SCRATCH_W1+1 cmp #'$' beq _hex cmp #'%' beq _bin pla jsr str2uword jmp _result _hex pla jsr hex2uword jmp _result _bin pla jsr bin2uword _result pha lda cx16.r15 sta P8ZP_SCRATCH_B1 ; result value pla sta cx16.r15 sty cx16.r15+1 lda P8ZP_SCRATCH_B1 rts }} } inline asmsub str2ubyte(str string @AY) clobbers(Y) -> ubyte @A { ; -- returns in A the unsigned byte value of the string number argument in AY ; the number may NOT be preceded by a + sign and may NOT contain spaces ; (any non-digit character will terminate the number string that is parsed) ; result in A, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ jsr conv.str2uword }} } inline asmsub str2byte(str string @AY) clobbers(Y) -> ubyte @A { ; -- returns in A the signed byte value of the string number argument in AY ; the number may be preceded by a + or - sign but may NOT contain spaces ; (any non-digit character will terminate the number string that is parsed) ; result in A, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ jsr conv.str2word }} } asmsub str2uword(str string @AY) -> uword @AY { ; -- returns the unsigned word value of the string number argument in AY ; the number may NOT be preceded by a + sign and may NOT contain spaces ; (any non-digit character will terminate the number string that is parsed) ; result in AY, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ _result = P8ZP_SCRATCH_W1 sta P8ZP_SCRATCH_W2 sty P8ZP_SCRATCH_W2+1 ldy #0 sty _result sty _result+1 sty cx16.r15+1 _loop lda (P8ZP_SCRATCH_W2),y sec sbc #48 bpl _digit _done sty cx16.r15 lda _result ldy _result+1 rts _digit cmp #10 bcs _done ; add digit to result pha jsr _result_times_10 pla clc adc _result sta _result bcc + inc _result+1 + iny bne _loop ; never reached _result_times_10 ; (W*4 + W)*2 lda _result+1 sta P8ZP_SCRATCH_REG lda _result asl a rol P8ZP_SCRATCH_REG asl a rol P8ZP_SCRATCH_REG clc adc _result sta _result lda P8ZP_SCRATCH_REG adc _result+1 asl _result rol a sta _result+1 rts }} } asmsub str2word(str string @AY) -> word @AY { ; -- returns the signed word value of the string number argument in AY ; the number may be preceded by a + or - sign but may NOT contain spaces ; (any non-digit character will terminate the number string that is parsed) ; result in AY, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ _result = P8ZP_SCRATCH_W1 sta P8ZP_SCRATCH_W2 sty P8ZP_SCRATCH_W2+1 ldy #0 sty _result sty _result+1 sty _negative sty cx16.r15+1 lda (P8ZP_SCRATCH_W2),y cmp #'+' bne + iny + cmp #'-' bne _parse inc _negative iny _parse lda (P8ZP_SCRATCH_W2),y sec sbc #48 bpl _digit _done sty cx16.r15 lda _negative beq + sec lda #0 sbc _result sta _result lda #0 sbc _result+1 sta _result+1 + lda _result ldy _result+1 rts _digit cmp #10 bcs _done ; add digit to result pha jsr str2uword._result_times_10 pla clc adc _result sta _result bcc + inc _result+1 + iny bne _parse ; never reached _negative .byte 0 }} } asmsub hex2uword(str string @AY) -> uword @AY { ; -- hexadecimal string (with or without '$') to uword. ; string may be in petscii or c64-screencode encoding. ; stops parsing at the first character that's not a hex digit (except leading $) ; result in AY, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ sta P8ZP_SCRATCH_W2 sty P8ZP_SCRATCH_W2+1 ldy #0 sty P8ZP_SCRATCH_W1 sty P8ZP_SCRATCH_W1+1 sty cx16.r15+1 lda (P8ZP_SCRATCH_W2),y beq _stop cmp #'$' bne _loop iny _loop lda #0 sta P8ZP_SCRATCH_B1 lda (P8ZP_SCRATCH_W2),y beq _stop cmp #7 ; screencode letters A-F are 1-6 bcc _add_letter cmp #'g' bcs _stop cmp #'a' bcs _add_letter cmp #'0' bcc _stop cmp #'9'+1 bcs _stop _calc asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 and #$0f clc adc P8ZP_SCRATCH_B1 ora P8ZP_SCRATCH_W1 sta P8ZP_SCRATCH_W1 iny bne _loop _stop sty cx16.r15 lda P8ZP_SCRATCH_W1 ldy P8ZP_SCRATCH_W1+1 rts _add_letter pha lda #9 sta P8ZP_SCRATCH_B1 pla jmp _calc }} } asmsub bin2uword(str string @AY) -> uword @AY { ; -- binary string (with or without '%') to uword. ; stops parsing at the first character that's not a 0 or 1. (except leading %) ; result in AY, number of characters processed also remains in cx16.r15 if you want to use it!! (0 = error) %asm {{ sta P8ZP_SCRATCH_W2 sty P8ZP_SCRATCH_W2+1 ldy #0 sty P8ZP_SCRATCH_W1 sty P8ZP_SCRATCH_W1+1 sty cx16.r15+1 lda (P8ZP_SCRATCH_W2),y beq _stop cmp #'%' bne _loop iny _loop lda (P8ZP_SCRATCH_W2),y cmp #'0' bcc _stop cmp #'2' bcs _stop _first asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 and #1 ora P8ZP_SCRATCH_W1 sta P8ZP_SCRATCH_W1 iny bne _loop _stop sty cx16.r15 lda P8ZP_SCRATCH_W1 ldy P8ZP_SCRATCH_W1+1 rts }} } }