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https://github.com/deater/dos33fsprogs.git
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c05084c289
probably broke something, but this also was a pain as was often accidentally using the vars, especially X and Y
109 lines
1.4 KiB
C
109 lines
1.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <math.h>
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#include "6502_emulate.h"
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#include "gr-sim.h"
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#define HGR_HORIZ 0xff
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#define TEMP_R 0xfe
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static void fancy_div(int d, int *q, int *r) {
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//;Divide by 7 (From December '84 Apple Assembly Line)
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//;15 bytes, 27 cycles
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// y=xhigh x=xlow a=??
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// q in y, r in a
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Y=(d>>8)&0xff;
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X=d&0xff;
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A=X;
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sta(TEMP_R);
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C=0;
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sta(HGR_HORIZ); // 0
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lsr(); // 0
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lsr(); // 0
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lsr(); // 0
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adc_mem(HGR_HORIZ); // 0
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ror(); // 0
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lsr(); // 0
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lsr(); // 0
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adc_mem(HGR_HORIZ); // 0
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ror(); // 0
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lsr(); // 0
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lsr(); // 0
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// calc remainder
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C=0;
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sta(HGR_HORIZ);
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asl();
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adc_mem(HGR_HORIZ);
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asl();
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adc_mem(HGR_HORIZ);
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// HGR_HORIZ=x/7, A=HGR_HORIZ*7
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C=1;
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eor(0xff);
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// printf("%d+%d=",d&0xff,a);
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adc(d&0xff);
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// printf("%d\n",a);
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// sta(TEMP_R);
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// txa();
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// sbc_mem(TEMP_R);
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// tax();
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if (Y) {
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C=0;
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adc(4);
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pha();
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lda(HGR_HORIZ);
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adc(36);
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sta(HGR_HORIZ);
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pla();
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}
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if (A>6) {
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C=1;
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sbc(7);
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ram[HGR_HORIZ]++;
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}
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Y=ram[HGR_HORIZ];
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*q=Y;
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*r=A;
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}
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int main(int argc, char **argv) {
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int i,actual_q,actual_r;
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int fancy_q,fancy_r;
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grsim_init();
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for(i=0;i<280;i++) {
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fancy_div(i,&fancy_q,&fancy_r);
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actual_q=i/7;
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actual_r=i%7;
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if ((fancy_q!=actual_q) || (fancy_r!=actual_r)) {
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printf("%03x\t%d,%d\t%d,%d\n",
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i,actual_q,actual_r,fancy_q,fancy_r);
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}
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}
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return 0;
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}
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