src/c64/c64mem.c

/*
 * c64mem.c -- C64 memory handling.
 *
 * Written by
 *  Andreas Boose <viceteam@t-online.de>
 *  Ettore Perazzoli <ettore@comm2000.it>
 *  Marco van den Heuvel <blackystardust68@yahoo.com>
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

#include "vice.h"

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

#include "alarm.h"
#include "c64.h"
#include "c64-resources.h"
#include "c64_256k.h"
#include "c64cart.h"
#include "c64cia.h"
#include "c64mem.h"
#include "c64meminit.h"
#include "c64memlimit.h"
#include "c64memrom.h"
#include "c64pla.h"
#include "c64ui.h"
#include "c64cartmem.h"
#include "cartio.h"
#include "cartridge.h"
#include "cia.h"
#include "clkguard.h"
#include "machine.h"
#include "maincpu.h"
#include "mem.h"
#include "monitor.h"
#include "plus256k.h"
#include "plus60k.h"
#include "ram.h"
#include "resources.h"
#include "reu.h"
#include "sid.h"
#include "tpi.h"
#include "vicii-mem.h"
#include "vicii-phi1.h"
#include "vicii.h"

/* Machine class (moved from c64.c to distinguish between x64 and x64sc) */
int machine_class = VICE_MACHINE_C64;

/* C64 memory-related resources.  */

/* ------------------------------------------------------------------------- */

/* Number of possible memory configurations.  */
#define NUM_CONFIGS     32

/* Number of possible video banks (16K each).  */
#define NUM_VBANKS      4

/* The C64 memory.  */
uint8_t mem_ram[C64_RAM_SIZE];

#ifdef USE_EMBEDDED
#include "c64chargen.h"
#else
uint8_t mem_chargen_rom[C64_CHARGEN_ROM_SIZE];
#endif

/* Internal color memory.  */
static uint8_t mem_color_ram[0x400];
uint8_t *mem_color_ram_cpu, *mem_color_ram_vicii;

/* Pointer to the chargen ROM.  */
uint8_t *mem_chargen_rom_ptr;

/* Pointers to the currently used memory read and write tables.  */
read_func_ptr_t *_mem_read_tab_ptr;
store_func_ptr_t *_mem_write_tab_ptr;
static uint8_t **_mem_read_base_tab_ptr;
static uint32_t *mem_read_limit_tab_ptr;

/* Memory read and write tables.  */
static store_func_ptr_t mem_write_tab[NUM_VBANKS][NUM_CONFIGS][0x101];
static read_func_ptr_t mem_read_tab[NUM_CONFIGS][0x101];
static uint8_t *mem_read_base_tab[NUM_CONFIGS][0x101];
static uint32_t mem_read_limit_tab[NUM_CONFIGS][0x101];

static store_func_ptr_t mem_write_tab_watch[0x101];
static read_func_ptr_t mem_read_tab_watch[0x101];

/* Current video bank (0, 1, 2 or 3).  */
static int vbank;

/* Current memory configuration.  */
static int mem_config;

/* Tape sense status: 1 = some button pressed, 0 = no buttons pressed.  */
static int tape_sense = 0;

static int tape_write_in = 0;
static int tape_motor_in = 0;

/* Current watchpoint state. 1 = watchpoints active, 0 = no watchpoints */
static int watchpoints_active;

/* ------------------------------------------------------------------------- */

static uint8_t zero_read_watch(uint16_t addr)
{
    addr &= 0xff;
    monitor_watch_push_load_addr(addr, e_comp_space);
    return mem_read_tab[mem_config][0](addr);
}

static void zero_store_watch(uint16_t addr, uint8_t value)
{
    addr &= 0xff;
    monitor_watch_push_store_addr(addr, e_comp_space);
    mem_write_tab[vbank][mem_config][0](addr, value);
}

static uint8_t read_watch(uint16_t addr)
{
    monitor_watch_push_load_addr(addr, e_comp_space);
    return mem_read_tab[mem_config][addr >> 8](addr);
}

static void store_watch(uint16_t addr, uint8_t value)
{
    monitor_watch_push_store_addr(addr, e_comp_space);
    mem_write_tab[vbank][mem_config][addr >> 8](addr, value);
}

void mem_toggle_watchpoints(int flag, void *context)
{
    if (flag) {
        _mem_read_tab_ptr = mem_read_tab_watch;
        _mem_write_tab_ptr = mem_write_tab_watch;
    } else {
        _mem_read_tab_ptr = mem_read_tab[mem_config];
        _mem_write_tab_ptr = mem_write_tab[vbank][mem_config];
    }
    watchpoints_active = flag;
}

/* ------------------------------------------------------------------------- */

/* $00/$01 unused bits emulation

   - There are 2 different unused bits, 1) the output bits, 2) the input bits
   - The output bits can be (re)set when the data-direction is set to output
     for those bits and the output bits will not drop-off to 0.
   - When the data-direction for the unused bits is set to output then the
     unused input bits can be (re)set by writing to them, when set to 1 the
     drop-off timer will start which will cause the unused input bits to drop
     down to 0 in a certain amount of time.
   - When an unused input bit already had the drop-off timer running, and is
     set to 1 again, the drop-off timer will restart.
   - when a an unused bit changes from output to input, and the current output
     bit is 1, the drop-off timer will restart again

    see testprogs/CPU/cpuport for details and tests
*/

static void clk_overflow_callback(CLOCK sub, void *unused_data)
{
    if (pport.data_set_clk_bit6 > (CLOCK)0) {
        pport.data_set_clk_bit6 -= sub;
    }
    if (pport.data_falloff_bit6 && (pport.data_set_clk_bit6 < maincpu_clk)) {
        pport.data_falloff_bit6 = 0;
        pport.data_set_bit6 = 0;
    }
    if (pport.data_set_clk_bit7 > (CLOCK)0) {
        pport.data_set_clk_bit7 -= sub;
    }
    if (pport.data_falloff_bit7 && (pport.data_set_clk_bit7 < maincpu_clk)) {
        pport.data_falloff_bit7 = 0;
        pport.data_set_bit7 = 0;
    }
}

void c64_mem_init(void)
{
    clk_guard_add_callback(maincpu_clk_guard, clk_overflow_callback, NULL);
}

void mem_pla_config_changed(void)
{
    mem_config = (((~pport.dir | pport.data) & 0x7) | (export.exrom << 3) | (export.game << 4));

    c64pla_config_changed(tape_sense, tape_write_in, tape_motor_in, 1, 0x17);

    if (watchpoints_active) {
        _mem_read_tab_ptr = mem_read_tab_watch;
        _mem_write_tab_ptr = mem_write_tab_watch;
    } else {
        _mem_read_tab_ptr = mem_read_tab[mem_config];
        _mem_write_tab_ptr = mem_write_tab[vbank][mem_config];
    }

    _mem_read_base_tab_ptr = mem_read_base_tab[mem_config];
    mem_read_limit_tab_ptr = mem_read_limit_tab[mem_config];

    maincpu_resync_limits();
}

uint8_t zero_read(uint16_t addr)
{
    uint8_t retval;

    addr &= 0xff;
#ifdef FEATURE_CPUMEMHISTORY
    if (!(memmap_state & MEMMAP_STATE_IGNORE)) {
        monitor_memmap_store(addr, (memmap_state & MEMMAP_STATE_OPCODE) ? MEMMAP_RAM_X : (memmap_state & MEMMAP_STATE_INSTR) ? 0 : MEMMAP_RAM_R);
        memmap_state &= ~(MEMMAP_STATE_OPCODE);
    }
#endif
    switch ((uint8_t)addr) {
        case 0:
            return pport.dir_read;
        case 1:
            retval = pport.data_read;

            /* discharge the "capacitor" */

            /* set real value of read bit 6 */
            if (pport.data_falloff_bit6 && (pport.data_set_clk_bit6 < maincpu_clk)) {
                pport.data_falloff_bit6 = 0;
                pport.data_set_bit6 = 0;
            }

            /* set real value of read bit 7 */
            if (pport.data_falloff_bit7 && (pport.data_set_clk_bit7 < maincpu_clk)) {
                pport.data_falloff_bit7 = 0;
                pport.data_set_bit7 = 0;
            }

            /* for unused bits in input mode, the value comes from the "capacitor" */

            /* set real value of bit 6 */
            if (!(pport.dir_read & 0x40)) {
                retval &= ~0x40;
                retval |= pport.data_set_bit6;
            }

            /* set real value of bit 7 */
            if (!(pport.dir_read & 0x80)) {
                retval &= ~0x80;
                retval |= pport.data_set_bit7;
            }

            return retval;
    }

    if (c64_256k_enabled) {
        return c64_256k_ram_segment0_read(addr);
    } else {
        if (plus256k_enabled) {
            return plus256k_ram_low_read(addr);
        } else {
            return mem_ram[addr & 0xff];
        }
    }
}

void zero_store(uint16_t addr, uint8_t value)
{
    addr &= 0xff;
#ifdef FEATURE_CPUMEMHISTORY
    monitor_memmap_store(addr, MEMMAP_RAM_W);
#endif
    switch ((uint8_t)addr) {
        case 0:
            if (vbank == 0) {
                if (c64_256k_enabled) {
                    c64_256k_ram_segment0_store((uint16_t)0, vicii_read_phi1_lowlevel());
                } else {
                    if (plus256k_enabled) {
                        plus256k_ram_low_store((uint16_t)0, vicii_read_phi1_lowlevel());
                    } else {
                        vicii_mem_vbank_store((uint16_t)0, vicii_read_phi1_lowlevel());
                    }
                }
            } else {
                mem_ram[0] = vicii_read_phi1_lowlevel();
                machine_handle_pending_alarms(maincpu_rmw_flag + 1);
            }
            /* when switching an unused bit from output (where it contained a
               stable value) to input mode (where the input is floating), some
               of the charge is transferred to the floating input */

            /* check if bit 6 has flipped */
            if ((pport.dir & 0x40)) {
                if ((pport.dir ^ value) & 0x40) {
                    pport.data_set_clk_bit6 = maincpu_clk + C64_CPU6510_DATA_PORT_FALL_OFF_CYCLES;
                    pport.data_set_bit6 = pport.data & 0x40;
                    pport.data_falloff_bit6 = 1;
                }
            }

            /* check if bit 7 has flipped */
            if ((pport.dir & 0x80)) {
                if ((pport.dir ^ value) & 0x80) {
                    pport.data_set_clk_bit7 = maincpu_clk + C64_CPU6510_DATA_PORT_FALL_OFF_CYCLES;
                    pport.data_set_bit7 = pport.data & 0x80;
                    pport.data_falloff_bit7 = 1;
                }
            }

            if (pport.dir != value) {
                pport.dir = value;
                mem_pla_config_changed();
            }
            break;
        case 1:
            if (vbank == 0) {
                if (c64_256k_enabled) {
                    c64_256k_ram_segment0_store((uint16_t)1, vicii_read_phi1_lowlevel());
                } else {
                    if (plus256k_enabled) {
                        plus256k_ram_low_store((uint16_t)1, vicii_read_phi1_lowlevel());
                    } else {
                        vicii_mem_vbank_store((uint16_t)1, vicii_read_phi1_lowlevel());
                    }
                }
            } else {
                mem_ram[1] = vicii_read_phi1_lowlevel();
                machine_handle_pending_alarms(maincpu_rmw_flag + 1);
            }

            /* when writing to an unused bit that is output, charge the "capacitor",
               otherwise don't touch it */
            if (pport.dir & 0x80) {
                pport.data_set_bit7 = value & 0x80;
                pport.data_set_clk_bit7 = maincpu_clk + C64_CPU6510_DATA_PORT_FALL_OFF_CYCLES;
                pport.data_falloff_bit7 = 1;
            }

            if (pport.dir & 0x40) {
                pport.data_set_bit6 = value & 0x40;
                pport.data_set_clk_bit6 = maincpu_clk + C64_CPU6510_DATA_PORT_FALL_OFF_CYCLES;
                pport.data_falloff_bit6 = 1;
            }

            if (pport.data != value) {
                pport.data = value;
                mem_pla_config_changed();
            }
            break;
        default:
            if (vbank == 0) {
                if (c64_256k_enabled) {
                    c64_256k_ram_segment0_store(addr, value);
                } else {
                    if (plus256k_enabled) {
                        plus256k_ram_low_store(addr, value);
                    } else {
                        vicii_mem_vbank_store(addr, value);
                    }
                }
            } else {
                mem_ram[addr] = value;
            }
    }
}

/* ------------------------------------------------------------------------- */

uint8_t chargen_read(uint16_t addr)
{
    return mem_chargen_rom[addr & 0xfff];
}

void chargen_store(uint16_t addr, uint8_t value)
{
    mem_chargen_rom[addr & 0xfff] = value;
}

uint8_t ram_read(uint16_t addr)
{
    return mem_ram[addr];
}

void ram_store(uint16_t addr, uint8_t value)
{
    mem_ram[addr] = value;
}

void ram_hi_store(uint16_t addr, uint8_t value)
{
    if (vbank == 3) {
        vicii_mem_vbank_3fxx_store(addr, value);
    } else {
        mem_ram[addr] = value;
    }

    if (addr == 0xff00) {
        reu_dma(-1);
    }
}

/* unconnected memory space */
static uint8_t void_read(uint16_t addr)
{
    return vicii_read_phi1();
}

static void void_store(uint16_t addr, uint8_t value)
{
    return;
}

/* ------------------------------------------------------------------------- */

/* Generic memory access.  */

void mem_store(uint16_t addr, uint8_t value)
{
    _mem_write_tab_ptr[addr >> 8](addr, value);
}

uint8_t mem_read(uint16_t addr)
{
    return _mem_read_tab_ptr[addr >> 8](addr);
}

void mem_store_without_ultimax(uint16_t addr, uint8_t value)
{
    store_func_ptr_t *write_tab_ptr;

    write_tab_ptr = mem_write_tab[vbank][mem_config & 7];

    write_tab_ptr[addr >> 8](addr, value);
}

uint8_t mem_read_without_ultimax(uint16_t addr)
{
    read_func_ptr_t *read_tab_ptr;

    read_tab_ptr = mem_read_tab[mem_config & 7];

    return read_tab_ptr[addr >> 8](addr);
}

void mem_store_without_romlh(uint16_t addr, uint8_t value)
{
    store_func_ptr_t *write_tab_ptr;

    write_tab_ptr = mem_write_tab[vbank][0];

    write_tab_ptr[addr >> 8](addr, value);
}

/* ------------------------------------------------------------------------- */

void colorram_store(uint16_t addr, uint8_t value)
{
    mem_color_ram[addr & 0x3ff] = value & 0xf;
}

uint8_t colorram_read(uint16_t addr)
{
    return mem_color_ram[addr & 0x3ff] | (vicii_read_phi1() & 0xf0);
}

/* ------------------------------------------------------------------------- */

/* init 256k memory table changes */
/* FIXME: make sure all cartridge related callbacks are hooked correctly */
static int check_256k_ram_write(int k, int i, int j)
{
    if (mem_write_tab[k][i][j] == vicii_mem_vbank_39xx_store) {
        return 1;
    }
    if (mem_write_tab[k][i][j] == vicii_mem_vbank_3fxx_store) {
        return 1;
    }
    if (mem_write_tab[k][i][j] == vicii_mem_vbank_store) {
        return 1;
    }
    if (mem_write_tab[k][i][j] == ram_hi_store) {
        return 1;
    }
    if (mem_write_tab[k][i][j] == ram_store) {
        return 1;
    }
    if (mem_write_tab[k][i][j] == raml_no_ultimax_store) { /* possibly breaks mmc64 and expert */
        return 1;
    }
    if (mem_write_tab[k][i][j] == romh_no_ultimax_store) { /* possibly breaks mmc64 and expert */
        return 1;
    }
    if (mem_write_tab[k][i][j] == ramh_no_ultimax_store) { /* possibly breaks mmc64 and expert */
        return 1;
    }
    if (mem_write_tab[k][i][j] == romh_store) {
        return 1;
    }
    return 0;
}

static void c64_256k_init_config(void)
{
    int i, j, k;

    if (c64_256k_enabled) {
        mem_limit_256k_init(mem_read_limit_tab);
        for (i = 0; i < NUM_CONFIGS; i++) {
            for (j = 1; j <= 0xff; j++) {
                for (k = 0; k < NUM_VBANKS; k++) {
                    if (check_256k_ram_write(k, i, j) == 1) {
                        if (j < 0x40) {
                            mem_write_tab[k][i][j] = c64_256k_ram_segment0_store;
                        }
                        if (j > 0x3f && j < 0x80) {
                            mem_write_tab[k][i][j] = c64_256k_ram_segment1_store;
                        }
                        if (j > 0x7f && j < 0xc0) {
                            mem_write_tab[k][i][j] = c64_256k_ram_segment2_store;
                        }
                        if (j > 0xbf) {
                            mem_write_tab[k][i][j] = c64_256k_ram_segment3_store;
                        }
                    }
                }
                if (mem_read_tab[i][j] == ram_read) {
                    if (j < 0x40) {
                        mem_read_tab[i][j] = c64_256k_ram_segment0_read;
                    }
                    if (j > 0x3f && j < 0x80) {
                        mem_read_tab[i][j] = c64_256k_ram_segment1_read;
                    }
                    if (j > 0x7f && j < 0xc0) {
                        mem_read_tab[i][j] = c64_256k_ram_segment2_read;
                    }
                    if (j > 0xbf) {
                        mem_read_tab[i][j] = c64_256k_ram_segment3_read;
                    }
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

/* init plus256k memory table changes */
/* FIXME: make sure all cartridge related callbacks are hooked correctly */
static void plus256k_init_config(void)
{
    int i, j, k;

    if (plus256k_enabled) {
        mem_limit_256k_init(mem_read_limit_tab);
        for (i = 0; i < NUM_CONFIGS; i++) {
            for (j = 1; j <= 0xff; j++) {
                for (k = 0; k < NUM_VBANKS; k++) {
                    if (check_256k_ram_write(k, i, j) == 1) {
                        if (j < 0x10) {
                            mem_write_tab[k][i][j] = plus256k_ram_low_store;
                        } else {
                            mem_write_tab[k][i][j] = plus256k_ram_high_store;
                        }
                    }
                }
                if (mem_read_tab[i][j] == ram_read) {
                    if (j < 0x10) {
                        mem_read_tab[i][j] = plus256k_ram_low_read;
                    } else {
                        mem_read_tab[i][j] = plus256k_ram_high_read;
                    }
                }
            }
        }
    }
}

/* init plus60k memory table changes */
/* FIXME: make sure all cartridge related callbacks are hooked correctly */
static void plus60k_init_config(void)
{
    int i, j, k;

    if (plus60k_enabled) {
        mem_limit_plus60k_init(mem_read_limit_tab);
        for (i = 0; i < NUM_CONFIGS; i++) {
            for (j = 0x10; j <= 0xff; j++) {
                for (k = 0; k < NUM_VBANKS; k++) {
                    if (mem_write_tab[k][i][j] == vicii_mem_vbank_39xx_store) {
                        mem_write_tab[k][i][j] = plus60k_vicii_mem_vbank_39xx_store;
                    }
                    if (mem_write_tab[k][i][j] == vicii_mem_vbank_3fxx_store) {
                        mem_write_tab[k][i][j] = plus60k_vicii_mem_vbank_3fxx_store;
                    }
                    if (mem_write_tab[k][i][j] == vicii_mem_vbank_store) {
                        mem_write_tab[k][i][j] = plus60k_vicii_mem_vbank_store;
                    }
                    if (mem_write_tab[k][i][j] == ram_hi_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_hi_store;
                    }
                    if (mem_write_tab[k][i][j] == ram_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_store;
                    }
                    if (mem_write_tab[k][i][j] == raml_no_ultimax_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_store; /* possibly breaks mmc64 and expert */
                    }
                    if (mem_write_tab[k][i][j] == romh_no_ultimax_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_store; /* possibly breaks mmc64 and expert */
                    }
                    if (mem_write_tab[k][i][j] == ramh_no_ultimax_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_store; /* possibly breaks mmc64 and expert */
                    }
                    if (mem_write_tab[k][i][j] == romh_store) {
                        mem_write_tab[k][i][j] = plus60k_ram_store;
                    }
                }
                if (mem_read_tab[i][j] == ram_read) {
                    mem_read_tab[i][j] = plus60k_ram_read;
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

void mem_set_write_hook(int config, int page, store_func_t *f)
{
    int i;

    for (i = 0; i < NUM_VBANKS; i++) {
        mem_write_tab[i][config][page] = f;
    }
}

void mem_read_tab_set(unsigned int base, unsigned int index, read_func_ptr_t read_func)
{
    mem_read_tab[base][index] = read_func;
}

void mem_read_base_set(unsigned int base, unsigned int index, uint8_t *mem_ptr)
{
    mem_read_base_tab[base][index] = mem_ptr;
}

void mem_initialize_memory(void)
{
    int i, j, k;
    int board;

    mem_chargen_rom_ptr = mem_chargen_rom;
    mem_color_ram_cpu = mem_color_ram;
    mem_color_ram_vicii = mem_color_ram;

    mem_limit_init(mem_read_limit_tab);

    /* setup watchpoint tables */
    mem_read_tab_watch[0] = zero_read_watch;
    mem_write_tab_watch[0] = zero_store_watch;
    for (i = 1; i <= 0x100; i++) {
        mem_read_tab_watch[i] = read_watch;
        mem_write_tab_watch[i] = store_watch;
    }

    resources_get_int("BoardType", &board);

    /* Default is RAM.  */
    for (i = 0; i < NUM_CONFIGS; i++) {
        mem_set_write_hook(i, 0, zero_store);
        mem_read_tab[i][0] = zero_read;
        mem_read_base_tab[i][0] = mem_ram;
        for (j = 1; j <= 0xfe; j++) {
            if (board == 1 && j >= 0x08) {
                mem_read_tab[i][j] = void_read;
                mem_read_base_tab[i][j] = NULL;
                mem_set_write_hook(0, j, void_store);
                continue;
            }
            mem_read_tab[i][j] = ram_read;
            mem_read_base_tab[i][j] = mem_ram;
            for (k = 0; k < NUM_VBANKS; k++) {
                if ((j & 0xc0) == (k << 6)) {
                    switch (j & 0x3f) {
                        case 0x39:
                            mem_write_tab[k][i][j] = vicii_mem_vbank_39xx_store;
                            break;
                        case 0x3f:
                            mem_write_tab[k][i][j] = vicii_mem_vbank_3fxx_store;
                            break;
                        default:
                            mem_write_tab[k][i][j] = vicii_mem_vbank_store;
                    }
                } else {
                    mem_write_tab[k][i][j] = ram_store;
                }
            }
        }
        if (board == 1) {
            mem_read_tab[i][0xff] = void_read;
            mem_read_base_tab[i][0xff] = NULL;
            mem_set_write_hook(0, 0xff, void_store);
        } else {
            mem_read_tab[i][0xff] = ram_read;
            mem_read_base_tab[i][0xff] = mem_ram;

            /* vbank access is handled within `ram_hi_store()'.  */
            mem_set_write_hook(i, 0xff, ram_hi_store);
        }
    }

    /* Setup character generator ROM at $D000-$DFFF (memory configs 1, 2, 3, 9, 10, 11, 26, 27).  */
    for (i = 0xd0; i <= 0xdf; i++) {
        mem_read_tab[1][i] = chargen_read;
        mem_read_tab[2][i] = chargen_read;
        mem_read_tab[3][i] = chargen_read;
        mem_read_tab[9][i] = chargen_read;
        mem_read_tab[10][i] = chargen_read;
        mem_read_tab[11][i] = chargen_read;
        mem_read_tab[26][i] = chargen_read;
        mem_read_tab[27][i] = chargen_read;
        mem_read_base_tab[1][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[2][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[3][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[9][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[10][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[11][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[26][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
        mem_read_base_tab[27][i] = (uint8_t *)(mem_chargen_rom - (uint8_t *)0xd000);
    }

    c64meminit(0);

    for (i = 0; i < NUM_CONFIGS; i++) {
        mem_read_tab[i][0x100] = mem_read_tab[i][0];
        for (j = 0; j < NUM_VBANKS; j++) {
            mem_write_tab[j][i][0x100] = mem_write_tab[j][i][0];
        }
        mem_read_base_tab[i][0x100] = mem_read_base_tab[i][0];
    }

    _mem_read_tab_ptr = mem_read_tab[7];
    _mem_write_tab_ptr = mem_write_tab[vbank][7];
    _mem_read_base_tab_ptr = mem_read_base_tab[7];
    mem_read_limit_tab_ptr = mem_read_limit_tab[7];

    vicii_set_chargen_addr_options(0x7000, 0x1000);

    c64pla_pport_reset();
    export.exrom = 0;
    export.game = 0;

    /* Setup initial memory configuration.  */
    mem_pla_config_changed();
    cartridge_init_config();
    /* internal expansions, these may modify the above mappings and must take
       care of hooking up all callbacks correctly.
    */
    plus60k_init_config();
    plus256k_init_config();
    c64_256k_init_config();

    if (board == 1) {
        mem_limit_max_init(mem_read_limit_tab);
    }
}

void mem_mmu_translate(unsigned int addr, uint8_t **base, int *start, int *limit)
{
    uint8_t *p = _mem_read_base_tab_ptr[addr >> 8];
    uint32_t limits;

    if (p != NULL && addr > 1) {
        *base = p;
        limits = mem_read_limit_tab_ptr[addr >> 8];
        *limit = limits & 0xffff;
        *start = limits >> 16;
    } else {
        cartridge_mmu_translate(addr, base, start, limit);
    }
}

/* ------------------------------------------------------------------------- */

/* Initialize RAM for power-up.  */
void mem_powerup(void)
{
    ram_init(mem_ram, 0x10000);
    cartridge_ram_init();  /* Clean cartridge ram too */
}

/* ------------------------------------------------------------------------- */

/* Change the current video bank.  Call this routine only when the vbank
   has really changed.  */
void mem_set_vbank(int new_vbank)
{
    vbank = new_vbank;

    /* Do not override watchpoints on vbank switches.  */
    if (_mem_write_tab_ptr != mem_write_tab_watch) {
        _mem_write_tab_ptr = mem_write_tab[new_vbank][mem_config];
    }

    vicii_set_vbank(new_vbank);
}

/* Set the tape sense status.  */
void mem_set_tape_sense(int sense)
{
    tape_sense = sense;
    mem_pla_config_changed();
}

/* Set the tape write in.  */
void mem_set_tape_write_in(int val)
{
    tape_write_in = val;
    mem_pla_config_changed();
}

/* Set the tape motor in.  */
void mem_set_tape_motor_in(int val)
{
    tape_motor_in = val;
    mem_pla_config_changed();
}

/* ------------------------------------------------------------------------- */

/* FIXME: this part needs to be checked.  */

void mem_get_basic_text(uint16_t *start, uint16_t *end)
{
    if (start != NULL) {
        *start = mem_ram[0x2b] | (mem_ram[0x2c] << 8);
    }
    if (end != NULL) {
        *end = mem_ram[0x2d] | (mem_ram[0x2e] << 8);
    }
}

void mem_set_basic_text(uint16_t start, uint16_t end)
{
    mem_ram[0x2b] = mem_ram[0xac] = start & 0xff;
    mem_ram[0x2c] = mem_ram[0xad] = start >> 8;
    mem_ram[0x2d] = mem_ram[0x2f] = mem_ram[0x31] = mem_ram[0xae] = end & 0xff;
    mem_ram[0x2e] = mem_ram[0x30] = mem_ram[0x32] = mem_ram[0xaf] = end >> 8;
}

void mem_inject(uint32_t addr, uint8_t value)
{
    /* could be made to handle various internal expansions in some sane way */
    mem_ram[addr & 0xffff] = value;
}

/* ------------------------------------------------------------------------- */

int mem_rom_trap_allowed(uint16_t addr)
{
    if (addr >= 0xe000) {
        switch (mem_config) {
            case 2:
            case 3:
            case 6:
            case 7:
            case 10:
            case 11:
            case 14:
            case 15:
            case 26:
            case 27:
            case 30:
            case 31:
                return 1;
            default:
                return 0;
        }
    }

    return 0;
}

/* ------------------------------------------------------------------------- */

/* Banked memory access functions for the monitor.  */

void store_bank_io(uint16_t addr, uint8_t byte)
{
    switch (addr & 0xff00) {
        case 0xd000:
            c64io_d000_store(addr, byte);
            break;
        case 0xd100:
            c64io_d100_store(addr, byte);
            break;
        case 0xd200:
            c64io_d200_store(addr, byte);
            break;
        case 0xd300:
            c64io_d300_store(addr, byte);
            break;
        case 0xd400:
            c64io_d400_store(addr, byte);
            break;
        case 0xd500:
            c64io_d500_store(addr, byte);
            break;
        case 0xd600:
            c64io_d600_store(addr, byte);
            break;
        case 0xd700:
            c64io_d700_store(addr, byte);
            break;
        case 0xd800:
        case 0xd900:
        case 0xda00:
        case 0xdb00:
            colorram_store(addr, byte);
            break;
        case 0xdc00:
            cia1_store(addr, byte);
            break;
        case 0xdd00:
            cia2_store(addr, byte);
            break;
        case 0xde00:
            c64io_de00_store(addr, byte);
            break;
        case 0xdf00:
            c64io_df00_store(addr, byte);
            break;
    }
    return;
}

uint8_t read_bank_io(uint16_t addr)
{
    switch (addr & 0xff00) {
        case 0xd000:
            return c64io_d000_read(addr);
        case 0xd100:
            return c64io_d100_read(addr);
        case 0xd200:
            return c64io_d200_read(addr);
        case 0xd300:
            return c64io_d300_read(addr);
        case 0xd400:
            return c64io_d400_read(addr);
        case 0xd500:
            return c64io_d500_read(addr);
        case 0xd600:
            return c64io_d600_read(addr);
        case 0xd700:
            return c64io_d700_read(addr);
        case 0xd800:
        case 0xd900:
        case 0xda00:
        case 0xdb00:
            return colorram_read(addr);
        case 0xdc00:
            return cia1_read(addr);
        case 0xdd00:
            return cia2_read(addr);
        case 0xde00:
            return c64io_de00_read(addr);
        case 0xdf00:
            return c64io_df00_read(addr);
    }
    return 0xff;
}

static uint8_t peek_bank_io(uint16_t addr)
{
    switch (addr & 0xff00) {
        case 0xd000:
            return c64io_d000_peek(addr);
        case 0xd100:
            return c64io_d100_peek(addr);
        case 0xd200:
            return c64io_d200_peek(addr);
        case 0xd300:
            return c64io_d300_peek(addr);
        case 0xd400:
            return c64io_d400_peek(addr);
        case 0xd500:
            return c64io_d500_peek(addr);
        case 0xd600:
            return c64io_d600_peek(addr);
        case 0xd700:
            return c64io_d700_peek(addr);
        case 0xd800:
        case 0xd900:
        case 0xda00:
        case 0xdb00:
            return colorram_read(addr);
        case 0xdc00:
            return cia1_peek(addr);
        case 0xdd00:
            return cia2_peek(addr);
        case 0xde00:
            return c64io_de00_peek(addr);
        case 0xdf00:
            return c64io_df00_peek(addr);
    }
    return 0xff;
}

/* ------------------------------------------------------------------------- */

/* Exported banked memory access functions for the monitor.  */

static const char *banknames[] = {
    "default",
    "cpu",
    "ram",
    "rom",
    "io",
    "cart",
    NULL
};

static const int banknums[] = { 1, 0, 1, 2, 3, 4 };

const char **mem_bank_list(void)
{
    return banknames;
}

int mem_bank_from_name(const char *name)
{
    int i = 0;

    while (banknames[i]) {
        if (!strcmp(name, banknames[i])) {
            return banknums[i];
        }
        i++;
    }
    return -1;
}

/* read memory with side-effects */
uint8_t mem_bank_read(int bank, uint16_t addr, void *context)
{
    switch (bank) {
        case 0:                   /* current */
            return mem_read(addr);
            break;
        case 3:                   /* io */
            if (addr >= 0xd000 && addr < 0xe000) {
                return read_bank_io(addr);
            }
            /* FALL THROUGH */
        case 4:                   /* cart */
            return cartridge_peek_mem(addr);
        case 2:                   /* rom */
            if (addr >= 0xa000 && addr <= 0xbfff) {
                return c64memrom_basic64_rom[addr & 0x1fff];
            }
            if (addr >= 0xd000 && addr <= 0xdfff) {
                return mem_chargen_rom[addr & 0x0fff];
            }
            if (addr >= 0xe000) {
                return c64memrom_kernal64_rom[addr & 0x1fff];
            }
            /* FALL THROUGH */
        case 1:                   /* ram */
            break;
    }
    return mem_ram[addr];
}

/* read memory without side-effects */
uint8_t mem_bank_peek(int bank, uint16_t addr, void *context)
{
    switch (bank) {
        case 0:                   /* current */
            /* we must check for which bank is currently active, and only use peek_bank_io
               when needed to avoid side effects */
            if (c64meminit_io_config[mem_config]) {
                if ((addr >= 0xd000) && (addr < 0xe000)) {
                    return peek_bank_io(addr);
                }
            }
            return mem_read(addr);
            break;
        case 3:                   /* io */
            if ((addr >= 0xd000) && (addr < 0xe000)) {
                return peek_bank_io(addr);
            }
            break;
        case 4:                   /* cart */
            return cartridge_peek_mem(addr);
    }
    return mem_bank_read(bank, addr, context);
}

void mem_bank_write(int bank, uint16_t addr, uint8_t byte, void *context)
{
    switch (bank) {
        case 0:                   /* current */
            mem_store(addr, byte);
            return;
        case 3:                   /* io */
            if (addr >= 0xd000 && addr < 0xe000) {
                store_bank_io(addr, byte);
                return;
            }
            /* FALL THROUGH */
        case 2:                   /* rom */
            if (addr >= 0xa000 && addr <= 0xbfff) {
                return;
            }
            if (addr >= 0xd000 && addr <= 0xdfff) {
                return;
            }
            if (addr >= 0xe000) {
                return;
            }
            /* FALL THROUGH */
        case 1:                   /* ram */
            break;
    }
    mem_ram[addr] = byte;
}

static int mem_dump_io(void *context, uint16_t addr)
{
    if ((addr >= 0xdc00) && (addr <= 0xdc3f)) {
        return ciacore_dump(machine_context.cia1);
    } else if ((addr >= 0xdd00) && (addr <= 0xdd3f)) {
        return ciacore_dump(machine_context.cia2);
    }
    return -1;
}

mem_ioreg_list_t *mem_ioreg_list_get(void *context)
{
    mem_ioreg_list_t *mem_ioreg_list = NULL;

    mon_ioreg_add_list(&mem_ioreg_list, "CIA1", 0xdc00, 0xdc0f, mem_dump_io, NULL);
    mon_ioreg_add_list(&mem_ioreg_list, "CIA2", 0xdd00, 0xdd0f, mem_dump_io, NULL);

    io_source_ioreg_add_list(&mem_ioreg_list);

    return mem_ioreg_list;
}

void mem_get_screen_parameter(uint16_t *base, uint8_t *rows, uint8_t *columns, int *bank)
{
    *base = ((vicii_peek(0xd018) & 0xf0) << 6) | ((~cia2_peek(0xdd00) & 0x03) << 14);
    *rows = 25;
    *columns = 40;
    *bank = 0;
}

/* ------------------------------------------------------------------------- */

void mem_color_ram_to_snapshot(uint8_t *color_ram)
{
    memcpy(color_ram, mem_color_ram, 0x400);
}

void mem_color_ram_from_snapshot(uint8_t *color_ram)
{
    memcpy(mem_color_ram, color_ram, 0x400);
}

/* ------------------------------------------------------------------------- */

/* UI functions (used to distinguish between x64 and x64sc) */
int c64_mem_ui_init_early(void)
{
    return c64ui_init_early();
}

int c64_mem_ui_init(void)
{
    return c64ui_init();
}

void c64_mem_ui_shutdown(void)
{
    c64ui_shutdown();
}