apple2ix/src/cpu-supp.c

/*
 * Apple // emulator for Linux: C support for 6502 on i386
 *
 * Copyright 1994 Alexander Jean-Claude Bottema
 * Copyright 1995 Stephen Lee
 * Copyright 1997, 1998 Aaron Culliney
 * Copyright 1998, 1999, 2000 Michael Deutschmann
 *
 * This software package is subject to the GNU General Public License
 * version 2 or later (your choice) as published by the Free Software
 * Foundation.
 *
 * THERE ARE NO WARRANTIES WHATSOEVER.
 *
 */

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

#include "cpu.h"

/* different than in defs.h! */
#define C_Flag_6502     0x1
#define X_Flag_6502     0x20
#define I_Flag_6502     0x4
#define V_Flag_6502     0x40
#define B_Flag_6502     0x10
#define D_Flag_6502     0x8
#define Z_Flag_6502     0x2
#define N_Flag_6502     0x80

static void initialize_code_tables(void)
{
    int i;

    for (i = 0; i < 256; i++)
    {
        unsigned char val = 0;

        if (i & C_Flag)
        {
            val |= C_Flag_6502;
        }

        if (i & X_Flag)
        {
            val |= X_Flag_6502;
        }

        if (i & I_Flag)
        {
            val |= I_Flag_6502;
        }

        if (i & V_Flag)
        {
            val |= V_Flag_6502;
        }

        if (i & B_Flag)
        {
            val |= B_Flag_6502;
        }

        if (i & D_Flag)
        {
            val |= D_Flag_6502;
        }

        if (i & Z_Flag)
        {
            val |= Z_Flag_6502;
        }

        if (i & N_Flag)
        {
            val |= N_Flag_6502;
        }

        cpu65_flags_encode[ i ] = val | 0x20;
        cpu65_flags_decode[ val ] = i;
    }
}


void cpu65_set(int flags)
{
    initialize_code_tables();

    switch (flags & 0xf)
    {
    case CPU65_NMOS:
        if (flags & CPU65_FAULT)
        {
            memcpy(cpu65__opcodes,cpu65__nmosbrk,1024);
        }
        else
        {
            memcpy(cpu65__opcodes,cpu65__nmos,1024);
        }

        break;
    case CPU65_C02:
        memcpy(cpu65__opcodes,cpu65__cmos,1024);
        break;
    default:
        abort();
    }

    cpu65__signal = 0;
}

void cpu65_interrupt(int reason)
{
    cpu65__signal = reason;
}