view transz80.c @ 921:2be771c4dfbd

After reviewing the results of my test ROM again it seems pretty clear that the VBlank flag gets set at the same time as the vcounter changes
author Michael Pavone <pavone@retrodev.com>
date Tue, 26 Jan 2016 19:23:10 -0800
parents 759c38bf97f8
children
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/*
 Copyright 2013 Michael Pavone
 This file is part of BlastEm.
 BlastEm is free software distributed under the terms of the GNU General Public License version 3 or greater. See COPYING for full license text.
*/
#include "z80inst.h"
#include "z80_to_x86.h"
#include "mem.h"
#include "vdp.h"
#include <stdio.h>
#include <stdlib.h>

uint8_t z80_ram[0x2000];
uint16_t cart[0x200000];

#define MCLKS_PER_Z80 15
//TODO: Figure out the exact value for this
#define MCLKS_PER_FRAME (MCLKS_LINE*262)
#define VINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_Z80)
#define CYCLE_NEVER 0xFFFFFFFF

uint8_t z80_read_ym(uint16_t location, z80_context * context)
{
	return 0xFF;
}

z80_context * z80_write_ym(uint16_t location, z80_context * context, uint8_t value)
{
	return context;
}

z80_context * z80_vdp_port_write(uint16_t location, z80_context * context, uint8_t value)
{
	return context;
}

int main(int argc, char ** argv)
{
	long filesize;
	uint8_t *filebuf;
	z80_options opts;
	z80_context context;
	if (argc < 2) {
		fputs("usage: transz80 zrom [cartrom]\n", stderr);
		exit(1);
	}
	FILE * f = fopen(argv[1], "rb");
	if (!f) {
		fprintf(stderr, "unable to open file %s\n", argv[2]);
		exit(1);
	}
	fseek(f, 0, SEEK_END);
	filesize = ftell(f);
	fseek(f, 0, SEEK_SET);
	fread(z80_ram, 1, filesize < sizeof(z80_ram) ? filesize : sizeof(z80_ram), f);
	fclose(f);
	if (argc > 2) {
		f = fopen(argv[2], "rb");
		if (!f) {
			fprintf(stderr, "unable to open file %s\n", argv[2]);
			exit(1);
		}
		fseek(f, 0, SEEK_END);
		filesize = ftell(f);
		fseek(f, 0, SEEK_SET);
		fread(cart, 1, filesize < sizeof(cart) ? filesize : sizeof(cart), f);
		fclose(f);
		for(unsigned short * cur = cart; cur - cart < (filesize/2); ++cur)
		{
			*cur = (*cur >> 8) | (*cur << 8);
		}
	}
	init_z80_opts(&opts);
	init_z80_context(&context, &opts);
	//Z80 RAM
	context.mem_pointers[0] = z80_ram;
	context.sync_cycle = context.target_cycle = MCLKS_PER_FRAME/MCLKS_PER_Z80;
	context.int_cycle = CYCLE_NEVER;
	//cartridge/bank
	context.mem_pointers[1] = context.mem_pointers[2] = (uint8_t *)cart;
	z80_reset(&context);
	for(;;)
	{
		z80_run(&context);
		if (context.current_cycle >= MCLKS_PER_FRAME/MCLKS_PER_Z80) {
			context.current_cycle -= MCLKS_PER_FRAME/MCLKS_PER_Z80;
		}
		if (context.current_cycle < VINT_CYCLE && context.iff1) {
			context.int_cycle = VINT_CYCLE;
		}
		context.target_cycle = context.sync_cycle < context.int_cycle ? context.sync_cycle : context.int_cycle;
	}
	return 0;
}