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/*
* interpreter.c is a tool which can be used to interpret 6502 machine code inline.
* Machine code is expected as hexadecimal of length 2 or 6, depending on the instruction.
* Note that zero-page addressing is not fully emulated yet; it will still address the zero-page
section of memory but the instructions still take an address of length 4.
This will be fixed later when the whole system is functional.
* There are a few special characters which print debug information
d Prints main system information
mXXXX Prints contents of particular memory location
*/
#include"include.h"
int charToNum (char c, int mul) {
if (c != 0x20 && (c >= 0x30 && c <= 0x39)){
a = (mul * (c - 0x30));
}else if (c != 0x20 && (c >= 0x41 && c <= 0x46)){
a = (mul * (c - 0x31));
}
}
void debug_print(){
printf("\nacc:\t%x\nX:\t%x\nY:\t%x\nstack:\t%x\nflags:\t%x", acc, X, Y, S, P);
}
int main(){
char c;
unsigned char a, b;
while(true){
// Pass 1
c = getchar();
if (c == EOF) break;
switch(c){
case D: case d:
debug_print();
break;
case M: case m:
int m = 0;
for(int i = 1; i <= 1000; i *= 10){
m += charToNum(getchar(), 1000/i);
}
printf("Address %d has %x", m, Memory[m]);
break;
}
a += charToNum(c, 0x10);
// Pass 2
c = getchar(); if (c == EOF) break;
a += charToNum(c, 0x01);
//Check for next value
c = getchar();
if (!(c == EOF || c == ' ')) {
// Four passes
b += charToNum(c, 0x1000);
c = getchar(); if (c == EOF) break;
b += charToNum(c, 0x0100);
c = getchar(); if (c == EOF) break;
b += charToNum(c, 0x0010);
c = getchar(); if (c == EOF) break;
b += charToNum(c, 0x0001);
}
runInstruction(a, b);
c = getchar(); if (c == EOF) break;
}
}
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