; ---- builtin functions func_any_b_stack .proc jsr func_any_b_into_A sta P8ESTACK_LO,x dex rts .pend func_all_b_stack .proc jsr func_all_b_into_A sta P8ESTACK_LO,x dex rts .pend func_any_b_into_A .proc ; -- any(array), array in P8ZP_SCRATCH_W1, num bytes in A sta _cmp_mod+1 ; self-modifying code ldy #0 - lda (P8ZP_SCRATCH_W1),y bne _got_any iny _cmp_mod cpy #255 ; modified bne - lda #0 rts _got_any lda #1 rts .pend func_all_b_into_A .proc ; -- all(array), array in P8ZP_SCRATCH_W1, num bytes in A sta _cmp_mod+1 ; self-modifying code ldy #0 - lda (P8ZP_SCRATCH_W1),y beq _got_not_all iny _cmp_mod cpy #255 ; modified bne - lda #1 _got_not_all rts .pend func_any_w_into_A .proc asl a jmp func_any_b_into_A .pend func_any_w_stack .proc asl a jsr func_any_b_into_A sta P8ESTACK_LO,x dex rts .pend func_all_w_into_A .proc ; -- all(warray), array in P8ZP_SCRATCH_W1, num bytes in A asl a ; times 2 because of word sta _cmp_mod+1 ; self-modifying code ldy #0 - lda (P8ZP_SCRATCH_W1),y bne + iny lda (P8ZP_SCRATCH_W1),y bne ++ lda #0 rts + iny + iny _cmp_mod cpy #255 ; modified bne - lda #1 rts .pend func_all_w_stack .proc jsr func_all_w_into_A sta P8ESTACK_LO,x dex rts .pend func_sin8_into_A .proc tay lda _sinecos8,y rts _sinecos8 .char trunc(127.0 * sin(range(256+64) * rad(360.0/256.0))) .pend func_sin8u_into_A .proc tay lda _sinecos8u,y rts _sinecos8u .byte trunc(128.0 + 127.5 * sin(range(256+64) * rad(360.0/256.0))) .pend func_sin8_stack .proc tay lda func_sin8_into_A._sinecos8,y sta P8ESTACK_LO,x dex rts .pend func_sin8u_stack .proc tay lda func_sin8u_into_A._sinecos8u,y sta P8ESTACK_LO,x dex rts .pend func_cos8_into_A .proc tay lda func_sin8_into_A._sinecos8+64,y rts .pend func_cos8u_into_A .proc tay lda func_sin8u_into_A._sinecos8u+64,y rts .pend func_cos8_stack .proc tay lda func_sin8_into_A._sinecos8+64,y sta P8ESTACK_LO,x dex rts .pend func_cos8u_stack .proc tay lda func_sin8u_into_A._sinecos8u+64,y sta P8ESTACK_LO,x dex rts .pend func_sin16_into_AY .proc tay lda _sinecos8lo,y pha lda _sinecos8hi,y tay pla rts _ := trunc(32767.0 * sin(range(256+64) * rad(360.0/256.0))) _sinecos8lo .byte <_ _sinecos8hi .byte >_ .pend func_sin16u_into_AY .proc tay lda _sinecos8ulo,y pha lda _sinecos8uhi,y tay pla rts _ := trunc(32768.0 + 32767.5 * sin(range(256+64) * rad(360.0/256.0))) _sinecos8ulo .byte <_ _sinecos8uhi .byte >_ .pend func_sin16_stack .proc tay lda func_sin16_into_AY._sinecos8lo,y sta P8ESTACK_LO,x lda func_sin16_into_AY._sinecos8hi,y sta P8ESTACK_HI,x dex rts .pend func_sin16u_stack .proc tay lda func_sin16u_into_AY._sinecos8ulo,y sta P8ESTACK_LO,x lda func_sin16u_into_AY._sinecos8uhi,y sta P8ESTACK_HI,x dex rts .pend func_cos16_into_AY .proc tay lda func_sin16_into_AY._sinecos8lo+64,y pha lda func_sin16_into_AY._sinecos8hi+64,y tay pla rts .pend func_cos16u_into_AY .proc tay lda func_sin16u_into_AY._sinecos8ulo+64,y pha lda func_sin16u_into_AY._sinecos8uhi+64,y tay pla rts .pend func_cos16_stack .proc tay lda func_sin16_into_AY._sinecos8lo+64,y sta P8ESTACK_LO,x lda func_sin16_into_AY._sinecos8hi+64,y sta P8ESTACK_HI,x dex rts .pend func_cos16u_stack .proc tay lda func_sin16u_into_AY._sinecos8ulo+64,y sta P8ESTACK_LO,x lda func_sin16u_into_AY._sinecos8uhi+64,y sta P8ESTACK_HI,x dex rts .pend abs_b_stack .proc ; -- push abs(A) on stack (as byte) jsr abs_b_into_A sta P8ESTACK_LO,x dex rts .pend abs_b_into_A .proc ; -- A = abs(A) cmp #0 bmi + rts + eor #$ff clc adc #1 rts .pend abs_w_stack .proc ; -- push abs(AY) on stack (as word) jsr abs_w_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend abs_w_into_AY .proc ; -- AY = abs(AY) cpy #0 bmi + rts + eor #$ff pha tya eor #$ff tay pla clc adc #1 bcc + iny + rts .pend func_sign_b_into_A .proc cmp #0 beq _zero bmi _neg lda #1 _zero rts _neg lda #-1 rts .pend func_sign_b_stack .proc jsr func_sign_b_into_A sta P8ESTACK_LO,x dex rts .pend func_sign_ub_into_A .proc cmp #0 bne _pos rts _pos lda #1 rts .pend func_sign_ub_stack .proc jsr func_sign_ub_into_A sta P8ESTACK_LO,x dex rts .pend func_sign_uw_into_A .proc cpy #0 beq _possibly_zero _pos lda #1 rts _possibly_zero cmp #0 bne _pos rts .pend func_sign_uw_stack .proc jsr func_sign_uw_into_A sta P8ESTACK_LO,x dex rts .pend func_sign_w_into_A .proc cpy #0 beq _possibly_zero bmi _neg _pos lda #1 rts _neg lda #-1 rts _possibly_zero cmp #0 bne _pos rts .pend func_sign_w_stack .proc jsr func_sign_w_into_A sta P8ESTACK_LO,x dex rts .pend func_sqrt16_stack .proc jsr func_sqrt16_into_A sta P8ESTACK_LO,x dex rts .pend func_sqrt16_into_A .proc ; integer square root from http://6502org.wikidot.com/software-math-sqrt sta P8ZP_SCRATCH_W1 sty P8ZP_SCRATCH_W1+1 txa pha lda #0 sta P8ZP_SCRATCH_B1 sta P8ZP_SCRATCH_REG ldx #8 - sec lda P8ZP_SCRATCH_W1+1 sbc #$40 tay lda P8ZP_SCRATCH_REG sbc P8ZP_SCRATCH_B1 bcc + sty P8ZP_SCRATCH_W1+1 sta P8ZP_SCRATCH_REG + rol P8ZP_SCRATCH_B1 asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 rol P8ZP_SCRATCH_REG asl P8ZP_SCRATCH_W1 rol P8ZP_SCRATCH_W1+1 rol P8ZP_SCRATCH_REG dex bne - pla tax lda P8ZP_SCRATCH_B1 rts .pend func_rnd_stack .proc ; -- put a random ubyte on the estack jsr math.randbyte sta P8ESTACK_LO,x dex rts .pend func_rndw_stack .proc ; -- put a random uword on the estack jsr math.randword sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_min_ub_into_A .proc ; -- min(ubarray) -> A. (array in P8ZP_SCRATCH_W1, num elements in A) tay dey lda #255 sta P8ZP_SCRATCH_B1 - lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_B1 bcs + sta P8ZP_SCRATCH_B1 + dey cpy #255 bne - lda P8ZP_SCRATCH_B1 rts .pend func_min_ub_stack .proc jsr func_min_ub_into_A sta P8ESTACK_LO,x dex rts .pend func_min_b_into_A .proc ; -- min(barray) -> A. (array in P8ZP_SCRATCH_W1, num elements in A) tay lda #127 sta P8ZP_SCRATCH_B1 - lda (P8ZP_SCRATCH_W1),y clc sbc P8ZP_SCRATCH_B1 bvc + eor #$80 + bpl + lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_B1 + dey cpy #255 bne - lda P8ZP_SCRATCH_B1 rts .pend func_min_b_stack .proc jsr func_min_b_into_A sta P8ESTACK_LO,x dex rts .pend func_min_uw_into_AY .proc ; -- min(uwarray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) asl a tay dey dey lda #$ff sta _result_minuw sta _result_minuw+1 _loop iny lda (P8ZP_SCRATCH_W1),y dey cmp _result_minuw+1 bcc _less bne _gtequ lda (P8ZP_SCRATCH_W1),y cmp _result_minuw bcs _gtequ _less lda (P8ZP_SCRATCH_W1),y sta _result_minuw iny lda (P8ZP_SCRATCH_W1),y sta _result_minuw+1 dey _gtequ dey dey cpy #254 bne _loop lda _result_minuw ldy _result_minuw+1 rts _result_minuw .word 0 .pend func_min_w_into_AY .proc ; -- min(warray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) asl a tay dey dey lda #$ff sta _result_minw lda #$7f sta _result_minw+1 _loop lda (P8ZP_SCRATCH_W1),y cmp _result_minw iny lda (P8ZP_SCRATCH_W1),y dey sbc _result_minw+1 bvc + eor #$80 + bpl _gtequ lda (P8ZP_SCRATCH_W1),y sta _result_minw iny lda (P8ZP_SCRATCH_W1),y sta _result_minw+1 dey _gtequ dey dey cpy #254 bne _loop lda _result_minw ldy _result_minw+1 rts _result_minw .word 0 .pend func_min_uw_stack .proc jsr func_min_uw_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_min_w_stack .proc jsr func_min_w_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_max_ub_into_A .proc ; -- max(ubarray) -> A (array in P8ZP_SCRATCH_W1, num elements in A) tay lda #0 sta P8ZP_SCRATCH_B1 - lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_B1 bcc + sta P8ZP_SCRATCH_B1 + dey cpy #255 bne - lda P8ZP_SCRATCH_B1 rts .pend func_max_ub_stack .proc jsr func_max_ub_into_A sta P8ESTACK_LO,x dex rts .pend func_max_b_into_A .proc ; -- max(barray) -> A (array in P8ZP_SCRATCH_W1, num elements in A) tay lda #-128 sta P8ZP_SCRATCH_B1 - lda (P8ZP_SCRATCH_W1),y sec sbc P8ZP_SCRATCH_B1 bvc + eor #$80 + bmi + lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_B1 + dey cpy #255 bne - lda P8ZP_SCRATCH_B1 rts .pend func_max_b_stack .proc jsr func_max_b_into_A sta P8ESTACK_LO,x dex rts .pend func_max_uw_into_AY .proc ; -- max(uwarray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) asl a tay dey dey lda #0 sta _result_maxuw sta _result_maxuw+1 _loop iny lda (P8ZP_SCRATCH_W1),y dey cmp _result_maxuw+1 bcc _lesseq bne _greater lda (P8ZP_SCRATCH_W1),y cmp _result_maxuw bcc _lesseq _greater lda (P8ZP_SCRATCH_W1),y sta _result_maxuw iny lda (P8ZP_SCRATCH_W1),y sta _result_maxuw+1 dey _lesseq dey dey cpy #254 bne _loop lda _result_maxuw ldy _result_maxuw+1 rts _result_maxuw .word 0 .pend func_max_uw_stack .proc jsr func_max_uw_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_max_w_into_AY .proc ; -- max(uwarray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) asl a tay dey dey lda #0 sta _result_maxw lda #$80 sta _result_maxw+1 _loop lda (P8ZP_SCRATCH_W1),y cmp _result_maxw iny lda (P8ZP_SCRATCH_W1),y dey sbc _result_maxw+1 bvc + eor #$80 + bmi _lesseq lda (P8ZP_SCRATCH_W1),y sta _result_maxw iny lda (P8ZP_SCRATCH_W1),y sta _result_maxw+1 dey _lesseq dey dey cpy #254 bne _loop lda _result_maxw ldy _result_maxw+1 rts _result_maxw .word 0 .pend func_max_w_stack .proc jsr func_max_w_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_sum_ub_into_AY .proc ; -- sum(ubarray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) tay dey lda #0 sta P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2+1 - lda (P8ZP_SCRATCH_W1),y clc adc P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2 bcc + inc P8ZP_SCRATCH_W2+1 + dey cpy #255 bne - lda P8ZP_SCRATCH_W2 ldy P8ZP_SCRATCH_W2+1 rts .pend func_sum_ub_stack .proc jsr func_sum_ub_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_sum_b_into_AY .proc ; -- sum(barray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) tay dey lda #0 sta P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2+1 _loop lda (P8ZP_SCRATCH_W1),y pha clc adc P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2 ; sign extend the high byte pla and #$80 beq + lda #$ff + adc P8ZP_SCRATCH_W2+1 sta P8ZP_SCRATCH_W2+1 dey cpy #255 bne _loop lda P8ZP_SCRATCH_W2 ldy P8ZP_SCRATCH_W2+1 rts .pend func_sum_b_stack .proc jsr func_sum_b_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_sum_uw_into_AY .proc ; -- sum(uwarray) -> AY (array in P8ZP_SCRATCH_W1, num elements in A) asl a tay dey dey lda #0 sta P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2+1 - lda (P8ZP_SCRATCH_W1),y iny clc adc P8ZP_SCRATCH_W2 sta P8ZP_SCRATCH_W2 lda (P8ZP_SCRATCH_W1),y adc P8ZP_SCRATCH_W2+1 sta P8ZP_SCRATCH_W2+1 dey dey dey cpy #254 bne - lda P8ZP_SCRATCH_W2 ldy P8ZP_SCRATCH_W2+1 rts .pend func_sum_uw_stack .proc jsr func_sum_uw_into_AY sta P8ESTACK_LO,x tya sta P8ESTACK_HI,x dex rts .pend func_sum_w_into_AY = func_sum_uw_into_AY func_sum_w_stack = func_sum_uw_stack func_sort_ub .proc ; 8bit unsigned sort ; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int) ; input: address of array to sort in P8ZP_SCRATCH_W1, length in S ; first, put pointer BEFORE array sta P8ZP_SCRATCH_B1 lda P8ZP_SCRATCH_W1 bne + dec P8ZP_SCRATCH_W1+1 + dec P8ZP_SCRATCH_W1 _sortloop ldy P8ZP_SCRATCH_B1 ;start of subroutine sort lda (P8ZP_SCRATCH_W1),y ;last value in (what is left of) sequence to be sorted sta P8ZP_SCRATCH_REG ;save value. will be over-written by largest number jmp _l2 _l1 dey beq _l3 lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_W2+1 bcc _l1 _l2 sty P8ZP_SCRATCH_W2 ;index of potentially largest value sta P8ZP_SCRATCH_W2+1 ;potentially largest value jmp _l1 _l3 ldy P8ZP_SCRATCH_B1 ;where the largest value shall be put lda P8ZP_SCRATCH_W2+1 ;the largest value sta (P8ZP_SCRATCH_W1),y ;put largest value in place ldy P8ZP_SCRATCH_W2 ;index of free space lda P8ZP_SCRATCH_REG ;the over-written value sta (P8ZP_SCRATCH_W1),y ;put the over-written value in the free space dec P8ZP_SCRATCH_B1 ;end of the shorter sequence still left bne _sortloop ;start working with the shorter sequence rts .pend func_sort_b .proc ; 8bit signed sort ; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int) ; input: address of array to sort in P8ZP_SCRATCH_W1, length in A ; first, put pointer BEFORE array sta P8ZP_SCRATCH_B1 lda P8ZP_SCRATCH_W1 bne + dec P8ZP_SCRATCH_W1+1 + dec P8ZP_SCRATCH_W1 _sortloop ldy P8ZP_SCRATCH_B1 ;start of subroutine sort lda (P8ZP_SCRATCH_W1),y ;last value in (what is left of) sequence to be sorted sta P8ZP_SCRATCH_REG ;save value. will be over-written by largest number jmp _l2 _l1 dey beq _l3 lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_W2+1 bmi _l1 _l2 sty P8ZP_SCRATCH_W2 ;index of potentially largest value sta P8ZP_SCRATCH_W2+1 ;potentially largest value jmp _l1 _l3 ldy P8ZP_SCRATCH_B1 ;where the largest value shall be put lda P8ZP_SCRATCH_W2+1 ;the largest value sta (P8ZP_SCRATCH_W1),y ;put largest value in place ldy P8ZP_SCRATCH_W2 ;index of free space lda P8ZP_SCRATCH_REG ;the over-written value sta (P8ZP_SCRATCH_W1),y ;put the over-written value in the free space dec P8ZP_SCRATCH_B1 ;end of the shorter sequence still left bne _sortloop ;start working with the shorter sequence rts .pend func_sort_uw .proc ; 16bit unsigned sort ; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int) ; input: address of array to sort in P8ZP_SCRATCH_W1, length in A ; first: subtract 2 of the pointer asl a sta P8ZP_SCRATCH_B1 lda P8ZP_SCRATCH_W1 sec sbc #2 sta P8ZP_SCRATCH_W1 bcs _sort_loop dec P8ZP_SCRATCH_W1+1 _sort_loop ldy P8ZP_SCRATCH_B1 ;start of subroutine sort lda (P8ZP_SCRATCH_W1),y ;last value in (what is left of) sequence to be sorted sta _work3 ;save value. will be over-written by largest number iny lda (P8ZP_SCRATCH_W1),y sta _work3+1 dey jmp _l2 _l1 dey dey beq _l3 iny lda (P8ZP_SCRATCH_W1),y dey cmp P8ZP_SCRATCH_W2+1 bne + lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_W2 + bcc _l1 _l2 sty _work1 ;index of potentially largest value lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_W2 ;potentially largest value iny lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_W2+1 dey jmp _l1 _l3 ldy P8ZP_SCRATCH_B1 ;where the largest value shall be put lda P8ZP_SCRATCH_W2 ;the largest value sta (P8ZP_SCRATCH_W1),y ;put largest value in place iny lda P8ZP_SCRATCH_W2+1 sta (P8ZP_SCRATCH_W1),y ldy _work1 ;index of free space lda _work3 ;the over-written value sta (P8ZP_SCRATCH_W1),y ;put the over-written value in the free space iny lda _work3+1 sta (P8ZP_SCRATCH_W1),y dey dec P8ZP_SCRATCH_B1 ;end of the shorter sequence still left dec P8ZP_SCRATCH_B1 bne _sort_loop ;start working with the shorter sequence rts _work1 .byte 0 _work3 .word 0 .pend func_sort_w .proc ; 16bit signed sort ; sorting subroutine coded by mats rosengren (mats.rosengren@esa.int) ; input: address of array to sort in P8ZP_SCRATCH_W1, length in A ; first: subtract 2 of the pointer asl a sta P8ZP_SCRATCH_B1 lda P8ZP_SCRATCH_W1 sec sbc #2 sta P8ZP_SCRATCH_W1 bcs _sort_loop dec P8ZP_SCRATCH_W1+1 _sort_loop ldy P8ZP_SCRATCH_B1 ;start of subroutine sort lda (P8ZP_SCRATCH_W1),y ;last value in (what is left of) sequence to be sorted sta _work3 ;save value. will be over-written by largest number iny lda (P8ZP_SCRATCH_W1),y sta _work3+1 dey jmp _l2 _l1 dey dey beq _l3 lda (P8ZP_SCRATCH_W1),y cmp P8ZP_SCRATCH_W2 iny lda (P8ZP_SCRATCH_W1),y dey sbc P8ZP_SCRATCH_W2+1 bvc + eor #$80 + bmi _l1 _l2 sty _work1 ;index of potentially largest value lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_W2 ;potentially largest value iny lda (P8ZP_SCRATCH_W1),y sta P8ZP_SCRATCH_W2+1 dey jmp _l1 _l3 ldy P8ZP_SCRATCH_B1 ;where the largest value shall be put lda P8ZP_SCRATCH_W2 ;the largest value sta (P8ZP_SCRATCH_W1),y ;put largest value in place iny lda P8ZP_SCRATCH_W2+1 sta (P8ZP_SCRATCH_W1),y ldy _work1 ;index of free space lda _work3 ;the over-written value sta (P8ZP_SCRATCH_W1),y ;put the over-written value in the free space iny lda _work3+1 sta (P8ZP_SCRATCH_W1),y dey dec P8ZP_SCRATCH_B1 ;end of the shorter sequence still left dec P8ZP_SCRATCH_B1 bne _sort_loop ;start working with the shorter sequence rts _work1 .byte 0 _work3 .word 0 .pend func_reverse_b .proc ; --- reverse an array of bytes (in-place) ; inputs: pointer to array in P8ZP_SCRATCH_W1, length in A _index_right = P8ZP_SCRATCH_W2 _index_left = P8ZP_SCRATCH_W2+1 _loop_count = P8ZP_SCRATCH_REG sta _loop_count lsr _loop_count sec sbc #1 sta _index_right lda #0 sta _index_left _loop ldy _index_right lda (P8ZP_SCRATCH_W1),y pha ldy _index_left lda (P8ZP_SCRATCH_W1),y ldy _index_right sta (P8ZP_SCRATCH_W1),y pla ldy _index_left sta (P8ZP_SCRATCH_W1),y inc _index_left dec _index_right dec _loop_count bne _loop rts .pend func_reverse_w .proc ; --- reverse an array of words (in-place) ; inputs: pointer to array in P8ZP_SCRATCH_W1, length in A _index_first = P8ZP_SCRATCH_W2 _index_second = P8ZP_SCRATCH_W2+1 _loop_count = P8ZP_SCRATCH_REG pha asl a ; *2 because words sec sbc #2 sta _index_first lda #0 sta _index_second pla lsr a pha sta _loop_count ; first reverse the lsbs _loop_lo ldy _index_first lda (P8ZP_SCRATCH_W1),y pha ldy _index_second lda (P8ZP_SCRATCH_W1),y ldy _index_first sta (P8ZP_SCRATCH_W1),y pla ldy _index_second sta (P8ZP_SCRATCH_W1),y inc _index_second inc _index_second dec _index_first dec _index_first dec _loop_count bne _loop_lo ; now reverse the msbs dec _index_second inc _index_first inc _index_first inc _index_first pla sta _loop_count _loop_hi ldy _index_first lda (P8ZP_SCRATCH_W1),y pha ldy _index_second lda (P8ZP_SCRATCH_W1),y ldy _index_first sta (P8ZP_SCRATCH_W1),y pla ldy _index_second sta (P8ZP_SCRATCH_W1),y dec _index_second dec _index_second inc _index_first inc _index_first dec _loop_count bne _loop_hi rts .pend func_exit .proc ; -- immediately exit the program with a return code in the A register jsr c64.CLRCHN ; reset i/o channels ldx orig_stackpointer txs rts ; return to original caller .pend func_read_flags_stack .proc ; -- put the processor status register on the stack php pla sta P8ESTACK_LO,x dex rts .pend func_memset .proc ; note: clobbers A,Y txa pha lda _arg_address sta P8ZP_SCRATCH_W1 lda _arg_address+1 sta P8ZP_SCRATCH_W1+1 ldx _arg_numbytes ldy _arg_numbytes+1 lda _arg_bytevalue jsr memset pla tax rts _arg_address .word 0 _arg_numbytes .word 0 _arg_bytevalue .byte 0 .pend func_memsetw .proc ; note: clobbers A,Y txa pha lda _arg_address sta P8ZP_SCRATCH_W1 lda _arg_address+1 sta P8ZP_SCRATCH_W1+1 lda _arg_numwords sta P8ZP_SCRATCH_W2 lda _arg_numwords+1 sta P8ZP_SCRATCH_W2+1 lda _arg_wordvalue ldy _arg_wordvalue+1 jsr memsetw pla tax rts _arg_address .word 0 _arg_numwords .word 0 _arg_wordvalue .word 0 .pend func_memcopy .proc ; memcopy of any number of bytes, note: clobbers A,Y stx P8ZP_SCRATCH_REG lda _arg_from sta P8ZP_SCRATCH_W1 lda _arg_from+1 sta P8ZP_SCRATCH_W1+1 lda _arg_to sta P8ZP_SCRATCH_W2 lda _arg_to+1 sta P8ZP_SCRATCH_W2+1 ldy #0 ldx _arg_numbytes+1 beq _remain - lda (P8ZP_SCRATCH_W1),y ; move a page at a time sta (P8ZP_SCRATCH_W2),y iny bne - inc P8ZP_SCRATCH_W1+1 inc P8ZP_SCRATCH_W2+1 dex bne - _remain ldx _arg_numbytes beq _done - lda (P8ZP_SCRATCH_W1),y ; move the remaining bytes sta (P8ZP_SCRATCH_W2),y iny dex bne - _done ldx P8ZP_SCRATCH_REG rts _arg_from .word 0 _arg_to .word 0 _arg_numbytes .word 0 .pend func_memcopy255 .proc ; fast memcopy of up to 255 bytes, note: clobbers A,Y ; note: also uses the _arg variables from regular func_memcopy stx P8ZP_SCRATCH_REG lda func_memcopy._arg_from sta P8ZP_SCRATCH_W1 lda func_memcopy._arg_from+1 sta P8ZP_SCRATCH_W1+1 lda func_memcopy._arg_to sta P8ZP_SCRATCH_W2 lda func_memcopy._arg_to+1 sta P8ZP_SCRATCH_W2+1 ldx func_memcopy._arg_numbytes ldy #0 - lda (P8ZP_SCRATCH_W1), y sta (P8ZP_SCRATCH_W2), y iny dex bne - ldx P8ZP_SCRATCH_REG rts .pend