Applerm-II/test.c

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

static uint8_t mem[0x10000];
static uint8_t key = 0x80;
static uint8_t last = 0x00;

void prn(int c) {
  uint8_t fp;
  __asm__("movs %0, r12": "=r"(fp));
  fprintf(stderr, "### $%02x ###\n", c);
  fflush(stderr);
  __asm__("movs r12, %0":: "r"(fp));
}

void cpu6502_dump(
    uint16_t pc, uint8_t a, uint8_t x, uint8_t y, uint8_t sp, uint8_t sr) {
  uint8_t fp;
  __asm__("movs %0, r12": "=r"(fp));
  fprintf(stderr, "*** dump *** PC=$%04x A=$%02x X=$%02x Y=$%02x SP=$%02x "
          "NV-B_DIZC=%d%d-%d_%d%d%d%d\n",
          pc, a, x, y, sp, (sr >> 7) & 1, (sr >> 6) & 1, (sr >> 4) & 1,
          (sr >> 3) & 1, (sr >> 2) & 1, (sr >> 1) & 1, sr & 1);
  fflush(stderr);
  __asm__("movs r12, %0":: "r"(fp));
}

uint8_t cpu6502_load(uint16_t addr) {
  uint8_t fp;
  uint8_t result = 0;
  __asm__("movs %0, r12": "=r"(fp));
  if (0x0400 <= addr && addr <= 0x7ff) {
    // Fake text VRAM.
    result = mem[addr];
  } else if ((0x0300 <= addr && addr <= 0x03ff) ||
             (0x0900 <= addr && addr <= 0x0fff)) {
    // Fake memory impl to make it run on low memory chip.
    result = last;
  } else if (0x1000 <= addr & addr < 0xbfff) {
    // Bus error due to minimum memory installation.
    return 0xff;
    fprintf(stdout, "\e[1;1Hinvalid load $%04x\n", addr);
    fflush(stdout);
    abort();
  } else if (0xc000 <= addr & addr < 0xcfff) {
    // I/O emulation.
    if (0xc000 == addr)
      result = key;
    if (0xc010 == addr)
      key &= 0x7f;
  } else {
    // Installed memory.
    result = mem[addr];
  }
  fprintf(stderr, "load  $%04x => $%02x\n", addr, result);
  fflush(stderr);
  __asm__("movs r12, %0":: "r"(fp));
  return result;
}

void cpu6502_store(uint16_t addr, uint8_t data) {
  uint8_t fp;
  __asm__("movs %0, r12": "=r"(fp));
  if (0x0400 <= addr && addr <= 0x7ff) {
    // Fake text VRAM.
    char ascii[0x40] =
        "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_ !\"#$%&'()*+,-./0123456789:;<=>?";
    mem[addr] = data;
    int y = (addr - 0x400) >> 7;
    int x = addr & 0x7f;
    if (x >= 0x50) {
      x -= 0x50;
      y += 0x10;
    } else if (x >= 0x28) {
      x -= 0x28;
      y += 0x08;
    }
    if (y < 24)
      printf("\e[%d;%dH%c", y + 2, x + 1, ascii[data & 0x3f]);
  } else if ((0x0300 <= addr && addr <= 0x03ff) ||
             (0x0900 <= addr && addr <= 0x0fff)) {
    // Fake memory impl to make it run on low memory chip.
    last = data;
  } else if (0x1000 <= addr & addr < 0xcfff) {
    // Bus error due to minimum memory installation.
    return;
    fprintf(stdout, "\e[1;1Hinvalid store $%04x\n", addr);
    fflush(stdout);
    abort();
  } else {
    // Installed memory.
    mem[addr] = data;
  }
  fprintf(stderr, "store $%04x <= $%02x\n", addr, data);
  fflush(stderr);
  __asm__("movs r12, %0":: "r"(fp));
}

int main(int argc, char** argv) {
  FILE* fp = fopen("applebasic.rom", "rb");
  //FILE* fp = fopen("apple2o.rom", "rb");
  memset(mem, 0, 0x10000);
  fread(&mem[0xd000], 1, 0x3000, fp);
  fclose(fp);
  cpu6502_reset();
  fprintf(stderr, "quit: $%04x\n", cpu6502_run());
  return 0;
}