66 lines
663 B
C
66 lines
663 B
C
#include <u.h>
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#include <libc.h>
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#include "dat.h"
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#include "fns.h"
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u8int *mem;
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u8int *romptr;
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u8int
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memread(u16int a)
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{
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return mem[a];
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}
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void
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memwrite(u16int a, u8int v)
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{
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if((void*)a < romptr)
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mem[a] = v;
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}
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void
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push8(u8int v)
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{
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memwrite(0x100 | rS--, v);
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}
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void
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push16(u16int v)
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{
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memwrite(0x100 | rS--, v >> 8);
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memwrite(0x100 | rS--, v);
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}
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u8int
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pop8(void)
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{
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return memread(0x100 | ++rS);
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}
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u16int
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pop16(void)
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{
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u16int v;
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v = memread(0x100 | ++rS);
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v |= memread(0x100 | ++rS) << 8;
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return v;
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}
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u8int
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fetch8(void)
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{
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return memread(pc++);
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}
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u16int
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fetch16(void)
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{
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u16int r;
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r = memread(pc++);
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r |= memread(pc++) << 8;
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return r;
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}
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