cbm3001-memtest/emu6502.c

102 lines
3.8 KiB
C
Raw Normal View History

2022-02-06 06:52:57 +01:00
#include <fcntl.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <malloc.h>
#include <string.h>
#include <sys/mman.h>
extern uint32_t instructions;
extern void reset6502(void);
extern void step6502(void);
uint8_t *ram, *screen, *a000, *b000, *c000, *d000, *e000, *f000;
uint8_t read6502(uint16_t address) {
if (address == 0xf27e) {
printf("DONE\n");
exit(0);
}
uint8_t value = 0x00;
if (address < 0x4000) {
// emulate memory error in uppermost page
if (address >= 0x3ff0) {
value = ram[address] & 0xf7;
} else {
value = ram[address];
}
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0x8000 && address <= 0x8fff) {
// screen buffer is mirrored 4 times, discard upper 2 bytes
value = screen[address & 0x03ff];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xa000 && address <= 0xafff) {
value = a000[address-0xa000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xb000 && address <= 0xbfff) {
value = b000[address-0xb000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xc000 && address <= 0xcfff) {
value = c000[address-0xc000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xd000 && address <= 0xdfff) {
value = d000[address-0xd000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xe000 && address <= 0xe7ff) {
value = e000[address-0xe000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else if (address >= 0xf000) {
value = f000[address-0xf000];
printf("%08x: READ %04x -> %02x\n", instructions, address, value);
} else {
printf("%08x: READ %04x -> not implemented\n", instructions, address);
}
return value;
}
void write6502(uint16_t address, uint8_t value) {
if (address < 0x4000) {
printf("%08x: WRITE %04x <- %02x\n", instructions, address, value);
ram[address] = value;
} else if (address >= 0x800 && address <= 0x8fff) {
printf("%08x: WRITE %04x <- %02x, SCREEN(%d,%d)\n", instructions, address, value, (address&0x03ff)%40, (address&0x03ff)/40);
screen[address & 0x03ff] = value;
} else {
printf("%08x: WRITE %04x <- %02x; READONLY\n", instructions, address, value);
}
}
int main() {
ram = (uint8_t*) malloc(0x4000);
screen = (uint8_t*) malloc(0x400);
memset(screen, 'X', 0x400);
int afd = open("memtest-9000.901465.bin", O_RDONLY);
a000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, afd, 0);
int bfd = open("memtest-9000.901465.bin", O_RDONLY);
b000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, bfd, 0);
int cfd = open("basic-2-c000.901465-01.bin", O_RDONLY);
c000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, cfd, 0);
int dfd = open("basic-2-d000.901465-02.bin", O_RDONLY);
d000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, dfd, 0);
int efd = open("edit-2-n.901447-24.bin", O_RDONLY);
e000 = mmap(0, 0x0800, PROT_READ, MAP_PRIVATE, efd, 0);
//int ffd = open("kernal-2.901465-03.bin", O_RDONLY);
int ffd = open("memtest-f000.901465+ascii.bin", O_RDONLY);
f000 = mmap(0, 0x1000, PROT_READ, MAP_PRIVATE, ffd, 0);
reset6502();
while (1) {
usleep(1);
step6502();
printf("pass: %02x, address: %02x%02x\n", ram[4], ram[1], ram[2]);
printf("┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓\n");
for (uint8_t row = 0; row < 25; ++row) {
printf("┃%.40s┃\n", screen + 40*row);
}
printf("┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛\n");
}
}