diff options
Diffstat (limited to 'interpreter.c')
-rw-r--r-- | interpreter.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/interpreter.c b/interpreter.c new file mode 100644 index 0000000..0df27ce --- /dev/null +++ b/interpreter.c @@ -0,0 +1,65 @@ +/* + * 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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