86Box/src/machine/m_xt_olivetti.c

/*
 * 86Box    A hypervisor and IBM PC system emulator that specializes in
 *          running old operating systems and software designed for IBM
 *          PC systems and compatibles from 1981 through fairly recent
 *          system designs based on the PCI bus.
 *
 *          This file is part of the 86Box distribution.
 *
 *          Emulation of the Olivetti XT-compatible machines.
 *
 *          - Supports MM58174 real-time clock emulation (M24)
 *          - Supports MM58274 real-time clock emulation (M240)
 *
 * Authors: Sarah Walker, <http://pcem-emulator.co.uk/>
 *          Miran Grca, <mgrca8@gmail.com>
 *          Fred N. van Kempen, <decwiz@yahoo.com>
 *          EngiNerd <webmaster.crrc@yahoo.it>
 *
 *          Copyright 2008-2019 Sarah Walker.
 *          Copyright 2016-2019 Miran Grca.
 *          Copyright 2017-2019 Fred N. van Kempen.
 *          Copyright 2020 EngiNerd.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <stdarg.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/timer.h>
#include <86box/io.h>
#include <86box/pic.h>
#include <86box/pit.h>
#include <86box/ppi.h>
#include <86box/nmi.h>
#include <86box/mem.h>
#include <86box/device.h>
#include <86box/nvr.h>
#include <86box/keyboard.h>
#include <86box/mouse.h>
#include <86box/rom.h>
#include <86box/fdd.h>
#include <86box/fdc.h>
#include <86box/fdc_ext.h>
#include <86box/gameport.h>
#include <86box/hdc.h>
#include <86box/port_6x.h>
#include <86box/sound.h>
#include <86box/snd_speaker.h>
#include <86box/video.h>
#include <86box/machine.h>
#include <86box/vid_cga.h>
#include <86box/vid_ogc.h>
#include <86box/vid_colorplus.h>
#include <86box/vid_cga_comp.h>

#define STAT_PARITY       0x80
#define STAT_RTIMEOUT     0x40
#define STAT_TTIMEOUT     0x20
#define STAT_LOCK         0x10
#define STAT_CD           0x08
#define STAT_SYSFLAG      0x04
#define STAT_IFULL        0x02
#define STAT_OFULL        0x01

#define PLANTRONICS_MODE  1
#define OLIVETTI_OGC_MODE 0

#define CGA_RGB           0
#define CGA_COMPOSITE     1

enum MM58174_ADDR {
        /* Registers */
        MM58174_TEST,       /* TEST register, write only */
        MM58174_TENTHS,     /* Tenths of second, read only */
        MM58174_SECOND1,    /* Units of seconds, read only */
        MM58174_SECOND10,   /* Tens of seconds, read only */
        MM58174_MINUTE1,
        MM58174_MINUTE10,
        MM58174_HOUR1,
        MM58174_HOUR10,
        MM58174_DAY1,
        MM58174_DAY10,
        MM58174_WEEKDAY,
        MM58174_MONTH1,
        MM58174_MONTH10,
        MM58174_LEAPYEAR,   /* Leap year status, write only */
        MM58174_RESET,      /* RESET register, write only */
        MM58174_IRQ         /* Interrupt register, read / write */
};

enum MM58274_ADDR {
        /* Registers */
        MM58274_CONTROL,    /* Control register */
        MM58274_TENTHS,     /* Tenths of second, read only */
        MM58274_SECOND1,
        MM58274_SECOND10,
        MM58274_MINUTE1,
        MM58274_MINUTE10,
        MM58274_HOUR1,
        MM58274_HOUR10,
        MM58274_DAY1,
        MM58274_DAY10,
        MM58274_MONTH1,
        MM58274_MONTH10,
        MM58274_YEAR1,
        MM58274_YEAR10,
        MM58274_WEEKDAY,
        MM58274_SETTINGS    /* Settings register */
};

static struct tm intclk;

typedef struct {
    /* Keyboard stuff. */
    int     wantirq;
    uint8_t command;
    uint8_t status;
    uint8_t out;
    uint8_t output_port;
    int     param,
        param_total;
    uint8_t params[16];
    uint8_t scan[7];

    /* Mouse stuff. */
    int        mouse_mode;
    int        x, y, b;
    pc_timer_t send_delay_timer;
} m24_kbd_t;

typedef struct {
    ogc_t       ogc;
    colorplus_t colorplus;
    int         mode;
} m19_vid_t;

static uint8_t key_queue[16];
static int     key_queue_start = 0,
           key_queue_end       = 0;

video_timings_t timing_m19_vid = { VIDEO_ISA, 8, 16, 32, 8, 16, 32 };

const device_t m19_vid_device;

#ifdef ENABLE_M24VID_LOG
int m24vid_do_log = ENABLE_M24VID_LOG;

static void
m24_log(const char *fmt, ...)
{
    va_list ap;

    if (m24vid_do_log) {
        va_start(ap, fmt);
        vfprintf(stdlog, fmt, ap);
        va_end(ap);
        fflush(stdlog);
    }
}
#else
#    define m24_log(fmt, ...)
#endif

/* Set the chip time. */
static void
mm58174_time_set(uint8_t *regs, struct tm *tm)
{
    regs[MM58174_SECOND1]  = (tm->tm_sec % 10);
    regs[MM58174_SECOND10] = (tm->tm_sec / 10);
    regs[MM58174_MINUTE1]  = (tm->tm_min % 10);
    regs[MM58174_MINUTE10] = (tm->tm_min / 10);
    regs[MM58174_HOUR1]    = (tm->tm_hour % 10);
    regs[MM58174_HOUR10]   = (tm->tm_hour / 10);
    regs[MM58174_WEEKDAY]  = (tm->tm_wday + 1);
    regs[MM58174_DAY1]     = (tm->tm_mday % 10);
    regs[MM58174_DAY10]    = (tm->tm_mday / 10);
    regs[MM58174_MONTH1]   = ((tm->tm_mon + 1) % 10);
    regs[MM58174_MONTH10]  = ((tm->tm_mon + 1) / 10);
    /* MM58174 does not store the year, M24 uses the IRQ register to count 8 years from leap year */
    regs[MM58174_IRQ]      = ((tm->tm_year + 1900) % 8);
    regs[MM58174_LEAPYEAR] = 8 >> ((regs[MM58174_IRQ] & 0x07) & 0x03);
}

/* Get the chip time. */
#define nibbles(a) (regs[(a##1)] + 10 * regs[(a##10)])
static void
mm58174_time_get(uint8_t *regs, struct tm *tm)
{
    tm->tm_sec  = nibbles(MM58174_SECOND);
    tm->tm_min  = nibbles(MM58174_MINUTE);
    tm->tm_hour = nibbles(MM58174_HOUR);
    tm->tm_wday = (regs[MM58174_WEEKDAY] - 1);
    tm->tm_mday = nibbles(MM58174_DAY);
    tm->tm_mon  = (nibbles(MM58174_MONTH) - 1);
    /* MM58174 does not store the year */
    tm->tm_year = (1984 + (regs[MM58174_IRQ] & 0x07) - 1900);
}

/* One more second has passed, update the internal clock. */
static void
mm58x74_recalc()
{
    /* Ping the internal clock. */
    if (++intclk.tm_sec == 60) {
        intclk.tm_sec = 0;
        if (++intclk.tm_min == 60) {
            intclk.tm_min = 0;
            if (++intclk.tm_hour == 24) {
                intclk.tm_hour = 0;
                if (++intclk.tm_mday == (nvr_get_days(intclk.tm_mon, intclk.tm_year) + 1)) {
                    intclk.tm_mday = 1;
                    if (++intclk.tm_mon == 13) {
                        intclk.tm_mon = 1;
                        intclk.tm_year++;
                    }
                }
            }
        }
    }
}

/* This is called every second through the NVR/RTC hook. */
static void
mm58174_tick(nvr_t *nvr)
{
    mm58x74_recalc();
    mm58174_time_set(nvr->regs, &intclk);
}

static void
mm58174_start(nvr_t *nvr)
{
    struct tm tm;

    /* Initialize the internal and chip times. */
    if (time_sync & TIME_SYNC_ENABLED) {
        /* Use the internal clock's time. */
        nvr_time_get(&tm);
        mm58174_time_set(nvr->regs, &tm);
    } else {
        /* Set the internal clock from the chip time. */
        mm58174_time_get(nvr->regs, &tm);
        nvr_time_set(&tm);
    }
    mm58174_time_get(nvr->regs, &intclk);
}

/* Write to one of the chip registers. */
static void
mm58174_write(uint16_t addr, uint8_t val, void *priv)
{
    nvr_t  *nvr = (nvr_t *) priv;

    addr &= 0x0f;
    val &= 0x0f;

    /* Update non-read-only changed values if not synchronizing time to host */
    if ((addr != MM58174_TENTHS) && (addr != MM58174_SECOND1) && (addr != MM58174_SECOND10)) 
        if ((nvr->regs[addr] != val) && !(time_sync & TIME_SYNC_ENABLED)) 
            nvr_dosave = 1;

    if ((addr == MM58174_RESET) && (val & 0x01)) {
        /* When timer starts, MM58174 sets seconds and tenths of second to 0 */
        nvr->regs[MM58174_TENTHS] = 0;
        if (!(time_sync & TIME_SYNC_ENABLED)) {
            /* Only set seconds to 0 if not synchronizing time to host clock */
            nvr->regs[MM58174_SECOND1] = 0;
            nvr->regs[MM58174_SECOND10] = 0;
        }
    }

    /* Store the new value */
    nvr->regs[addr] = val;

    /* Update internal clock with MM58174 time */
    mm58174_time_get(nvr->regs, &intclk);
}

/* Read from one of the chip registers. */
static uint8_t
mm58174_read(uint16_t addr, void *priv)
{
    nvr_t  *nvr = (nvr_t *) priv;

    addr &= 0x0f;

    /* Set IRQ control bit to 0 upon read */
    if (addr == 0x0f)
        nvr->regs[addr] &= 0x07;

    /* Grab and return the desired value */
    return (nvr->regs[addr]);
}

/* Reset the MM58174 to a default state. */
static void
mm58174_reset(nvr_t *nvr)
{
    /* Clear the NVRAM. */
    memset(nvr->regs, 0xff, nvr->size);

    /* Reset the RTC registers. */
    memset(nvr->regs, 0x00, 16);
    nvr->regs[MM58174_WEEKDAY] = 0x01;
    nvr->regs[MM58174_DAY1]    = 0x01;
    nvr->regs[MM58174_MONTH1]  = 0x01;
}

static void
mm58174_init(nvr_t *nvr, int size)
{
    /* This is machine specific. */
    nvr->size = size;
    nvr->irq  = -1;

    /* Set up any local handlers here. */
    nvr->reset = mm58174_reset;
    nvr->start = mm58174_start;
    nvr->tick  = mm58174_tick;

    /* Initialize the actual NVR. */
    nvr_init(nvr);

    io_sethandler(0x0070, 16,
                  mm58174_read, NULL, NULL, mm58174_write, NULL, NULL, nvr);
}

/* Set the chip time. */
static void
mm58274_time_set(uint8_t *regs, struct tm *tm)
{
    regs[MM58274_SECOND1]    = (tm->tm_sec % 10);
    regs[MM58274_SECOND10]   = (tm->tm_sec / 10);
    regs[MM58274_MINUTE1]    = (tm->tm_min % 10);
    regs[MM58274_MINUTE10]   = (tm->tm_min / 10);
    regs[MM58274_HOUR1]      = (tm->tm_hour % 10);
    regs[MM58274_HOUR10]     = (tm->tm_hour / 10);
    /* Store hour in 24-hour or 12-hour mode */
    if (regs[MM58274_SETTINGS] & 0x01) {
        regs[MM58274_HOUR1]  = (tm->tm_hour % 10);
        regs[MM58274_HOUR10] = (tm->tm_hour / 10);
    } else {
        regs[MM58274_HOUR1]  = ((tm->tm_hour % 12) % 10);
        regs[MM58274_HOUR10] = (((tm->tm_hour % 12) / 10));
        if (tm->tm_hour >= 12)
            regs[MM58274_SETTINGS] |= 0x04;
        else
            regs[MM58274_SETTINGS] &= 0x0B;
    }
    regs[MM58274_WEEKDAY]    = (tm->tm_wday + 1);
    regs[MM58274_DAY1]       = (tm->tm_mday % 10);
    regs[MM58274_DAY10]      = (tm->tm_mday / 10);
    regs[MM58274_MONTH1]     = ((tm->tm_mon + 1) % 10);
    regs[MM58274_MONTH10]    = ((tm->tm_mon + 1) / 10);
    /* MM58274 can store 00 to 99 years but M240 uses the YEAR1 register to count 8 years from leap year */
    regs[MM58274_YEAR1]      = ((tm->tm_year + 1900) % 8);
    /* Keep bit 0 and 1 12-hour / 24-hour and AM / PM */
    regs[MM58274_SETTINGS]  &= 0x03;
    /* Set leap counter bits 2 and 3 */
    regs[MM58274_SETTINGS]  += (4* (regs[MM58274_YEAR1] & 0x03));
}

/* Get the chip time. */
static void
mm58274_time_get(uint8_t *regs, struct tm *tm)
{
    tm->tm_sec      = nibbles(MM58274_SECOND);
    tm->tm_min      = nibbles(MM58274_MINUTE);
    /* Read hour in 24-hour or 12-hour mode */
    if (regs[MM58274_SETTINGS] & 0x01)
        tm->tm_hour = nibbles(MM58274_HOUR);
    else
        tm->tm_hour = ((nibbles(MM58274_HOUR) % 12) + (regs[MM58274_SETTINGS] & 0x04) ? 12 : 0);
    tm->tm_wday     = (regs[MM58274_WEEKDAY] - 1);
    tm->tm_mday     = nibbles(MM58274_DAY);
    tm->tm_mon      = (nibbles(MM58274_MONTH) - 1);
    /* MM58274 can store 00 to 99 years but M240 uses the YEAR1 register to count 8 years from leap year */
    tm->tm_year     = (1984 + regs[MM58274_YEAR1] - 1900);
}

/* This is called every second through the NVR/RTC hook. */
static void
mm58274_tick(nvr_t *nvr)
{
    mm58x74_recalc();
    mm58274_time_set(nvr->regs, &intclk);
}

static void
mm58274_start(nvr_t *nvr)
{
    struct tm tm;

    /* Initialize the internal and chip times. */
    if (time_sync & TIME_SYNC_ENABLED) {
        /* Use the internal clock's time. */
        nvr_time_get(&tm);
        mm58274_time_set(nvr->regs, &tm);
    } else {
        /* Set the internal clock from the chip time. */
        mm58274_time_get(nvr->regs, &tm);
        nvr_time_set(&tm);
    }
    mm58274_time_get(nvr->regs, &intclk);
}

/* Write to one of the chip registers. */
static void
mm58274_write(uint16_t addr, uint8_t val, void *priv)
{
    nvr_t  *nvr = (nvr_t *) priv;

    addr &= 0x0f;
    val &= 0x0f;

    /* Update non-read-only changed values if not synchronizing time to host */
    if ((addr != MM58274_TENTHS))
        if ((nvr->regs[addr] != val) && !(time_sync & TIME_SYNC_ENABLED)) 
            nvr_dosave = 1;

    if ((addr == MM58274_CONTROL) && (val & 0x04)) {
        /* When timer starts, MM58274 sets tenths of second to 0 */
        nvr->regs[MM58274_TENTHS] = 0;
    }

    /* Store the new value */
    nvr->regs[addr] = val;

    /* Update internal clock with MM58274 time */
    mm58274_time_get(nvr->regs, &intclk);
}

/* Read from one of the chip registers. */
static uint8_t
mm58274_read(uint16_t addr, void *priv)
{
    nvr_t  *nvr = (nvr_t *) priv;

    addr &= 0x0f;

    /* Grab and return the desired value */
    return (nvr->regs[addr]);
}

/* Reset the MM58274 to a default state. */
static void
mm58274_reset(nvr_t *nvr)
{
    /* Clear the NVRAM. */
    memset(nvr->regs, 0xff, nvr->size);

    /* Reset the RTC registers. */
    memset(nvr->regs, 0x00, 16);
    nvr->regs[MM58274_WEEKDAY]  = 0x01;
    nvr->regs[MM58274_DAY1]     = 0x01;
    nvr->regs[MM58274_MONTH1]   = 0x01;
    nvr->regs[MM58274_SETTINGS] = 0x01;
}

static void
mm58274_init(nvr_t *nvr, int size)
{
    /* This is machine specific. */
    nvr->size = size;
    nvr->irq  = -1;

    /* Set up any local handlers here. */
    nvr->reset = mm58274_reset;
    nvr->start = mm58274_start;
    nvr->tick  = mm58274_tick;

    /* Initialize the actual NVR. */
    nvr_init(nvr);

    io_sethandler(0x0070, 16,
                  mm58274_read, NULL, NULL, mm58274_write, NULL, NULL, nvr);
}

static void
m24_kbd_poll(void *priv)
{
    m24_kbd_t *m24_kbd = (m24_kbd_t *) priv;

    timer_advance_u64(&m24_kbd->send_delay_timer, 1000 * TIMER_USEC);
    if (m24_kbd->wantirq) {
        m24_kbd->wantirq = 0;
        picint(2);
#if ENABLE_KEYBOARD_LOG
        m24_log("M24: take IRQ\n");
#endif
    }

    if (!(m24_kbd->status & STAT_OFULL) && key_queue_start != key_queue_end) {
#if ENABLE_KEYBOARD_LOG
        m24_log("Reading %02X from the key queue at %i\n",
                m24_kbd->out, key_queue_start);
#endif
        m24_kbd->out    = key_queue[key_queue_start];
        key_queue_start = (key_queue_start + 1) & 0xf;
        m24_kbd->status |= STAT_OFULL;
        m24_kbd->status &= ~STAT_IFULL;
        m24_kbd->wantirq = 1;
    }
}

static void
m24_kbd_adddata(uint16_t val)
{
    key_queue[key_queue_end] = val;
    key_queue_end            = (key_queue_end + 1) & 0xf;
}

static void
m24_kbd_adddata_ex(uint16_t val)
{
    kbd_adddata_process(val, m24_kbd_adddata);
}

static void
m24_kbd_write(uint16_t port, uint8_t val, void *priv)
{
    m24_kbd_t *m24_kbd = (m24_kbd_t *) priv;

#if ENABLE_KEYBOARD_LOG
    m24_log("M24: write %04X %02X\n", port, val);
#endif

#if 0
    if (ram[8] == 0xc3)
	output = 3;
#endif
    switch (port) {
        case 0x60:
            if (m24_kbd->param != m24_kbd->param_total) {
                m24_kbd->params[m24_kbd->param++] = val;
                if (m24_kbd->param == m24_kbd->param_total) {
                    switch (m24_kbd->command) {
                        case 0x11:
                            m24_kbd->mouse_mode = 0;
                            m24_kbd->scan[0]    = m24_kbd->params[0];
                            m24_kbd->scan[1]    = m24_kbd->params[1];
                            m24_kbd->scan[2]    = m24_kbd->params[2];
                            m24_kbd->scan[3]    = m24_kbd->params[3];
                            m24_kbd->scan[4]    = m24_kbd->params[4];
                            m24_kbd->scan[5]    = m24_kbd->params[5];
                            m24_kbd->scan[6]    = m24_kbd->params[6];
                            break;

                        case 0x12:
                            m24_kbd->mouse_mode = 1;
                            m24_kbd->scan[0]    = m24_kbd->params[0];
                            m24_kbd->scan[1]    = m24_kbd->params[1];
                            m24_kbd->scan[2]    = m24_kbd->params[2];
                            break;

                        default:
                            m24_log("M24: bad keyboard command complete %02X\n", m24_kbd->command);
                    }
                }
            } else {
                m24_kbd->command = val;
                switch (val) {
                    case 0x01: /*Self-test*/
                        break;

                    case 0x05: /*Read ID*/
                        m24_kbd_adddata(0x00);
                        break;

                    case 0x11:
                        m24_kbd->param       = 0;
                        m24_kbd->param_total = 9;
                        break;

                    case 0x12:
                        m24_kbd->param       = 0;
                        m24_kbd->param_total = 4;
                        break;

                    default:
                        m24_log("M24: bad keyboard command %02X\n", val);
                }
            }
            break;

        case 0x61:
            ppi.pb = val;

            speaker_update();
            speaker_gated  = val & 1;
            speaker_enable = val & 2;
            if (speaker_enable)
                was_speaker_enable = 1;
            pit_devs[0].set_gate(pit_devs[0].data, 2, val & 1);
            break;
    }
}

static uint8_t
m24_kbd_read(uint16_t port, void *priv)
{
    m24_kbd_t *m24_kbd = (m24_kbd_t *) priv;
    uint8_t    ret     = 0xff;

    switch (port) {
        case 0x60:
            ret = m24_kbd->out;
            if (key_queue_start == key_queue_end) {
                m24_kbd->status &= ~STAT_OFULL;
                m24_kbd->wantirq = 0;
            } else {
                m24_kbd->out    = key_queue[key_queue_start];
                key_queue_start = (key_queue_start + 1) & 0xf;
                m24_kbd->status |= STAT_OFULL;
                m24_kbd->status &= ~STAT_IFULL;
                m24_kbd->wantirq = 1;
            }
            break;

        case 0x61:
            ret = ppi.pb;
            break;

        case 0x64:
            ret = m24_kbd->status;
            m24_kbd->status &= ~(STAT_RTIMEOUT | STAT_TTIMEOUT);
            break;

        default:
            m24_log("\nBad M24 keyboard read %04X\n", port);
    }

    return (ret);
}

static void
m24_kbd_close(void *priv)
{
    m24_kbd_t *kbd = (m24_kbd_t *) priv;

    /* Stop the timer. */
    timer_disable(&kbd->send_delay_timer);

    /* Disable scanning. */
    keyboard_scan = 0;

    keyboard_send = NULL;

    io_removehandler(0x0060, 2,
                     m24_kbd_read, NULL, NULL, m24_kbd_write, NULL, NULL, kbd);
    io_removehandler(0x0064, 1,
                     m24_kbd_read, NULL, NULL, m24_kbd_write, NULL, NULL, kbd);

    free(kbd);
}

static void
m24_kbd_reset(void *priv)
{
    m24_kbd_t *m24_kbd = (m24_kbd_t *) priv;

    /* Initialize the keyboard. */
    m24_kbd->status  = STAT_LOCK | STAT_CD;
    m24_kbd->wantirq = 0;
    keyboard_scan    = 1;
    m24_kbd->param = m24_kbd->param_total = 0;
    m24_kbd->mouse_mode                   = 0;
    m24_kbd->scan[0]                      = 0x1c;
    m24_kbd->scan[1]                      = 0x53;
    m24_kbd->scan[2]                      = 0x01;
    m24_kbd->scan[3]                      = 0x4b;
    m24_kbd->scan[4]                      = 0x4d;
    m24_kbd->scan[5]                      = 0x48;
    m24_kbd->scan[6]                      = 0x50;
}

static int
ms_poll(int x, int y, int z, int b, void *priv)
{
    m24_kbd_t *m24_kbd = (m24_kbd_t *) priv;

    m24_kbd->x += x;
    m24_kbd->y += y;

    if (((key_queue_end - key_queue_start) & 0xf) > 14)
        return (0xff);

    if ((b & 1) && !(m24_kbd->b & 1))
        m24_kbd_adddata(m24_kbd->scan[0]);
    if (!(b & 1) && (m24_kbd->b & 1))
        m24_kbd_adddata(m24_kbd->scan[0] | 0x80);
    m24_kbd->b = (m24_kbd->b & ~1) | (b & 1);

    if (((key_queue_end - key_queue_start) & 0xf) > 14)
        return (0xff);

    if ((b & 2) && !(m24_kbd->b & 2))
        m24_kbd_adddata(m24_kbd->scan[2]);
    if (!(b & 2) && (m24_kbd->b & 2))
        m24_kbd_adddata(m24_kbd->scan[2] | 0x80);
    m24_kbd->b = (m24_kbd->b & ~2) | (b & 2);

    if (((key_queue_end - key_queue_start) & 0xf) > 14)
        return (0xff);

    if ((b & 4) && !(m24_kbd->b & 4))
        m24_kbd_adddata(m24_kbd->scan[1]);
    if (!(b & 4) && (m24_kbd->b & 4))
        m24_kbd_adddata(m24_kbd->scan[1] | 0x80);
    m24_kbd->b = (m24_kbd->b & ~4) | (b & 4);

    if (m24_kbd->mouse_mode) {
        if (((key_queue_end - key_queue_start) & 0xf) > 12)
            return (0xff);

        if (!m24_kbd->x && !m24_kbd->y)
            return (0xff);

        m24_kbd->y = -m24_kbd->y;

        if (m24_kbd->x < -127)
            m24_kbd->x = -127;
        if (m24_kbd->x > 127)
            m24_kbd->x = 127;
        if (m24_kbd->x < -127)
            m24_kbd->x = 0x80 | ((-m24_kbd->x) & 0x7f);

        if (m24_kbd->y < -127)
            m24_kbd->y = -127;
        if (m24_kbd->y > 127)
            m24_kbd->y = 127;
        if (m24_kbd->y < -127)
            m24_kbd->y = 0x80 | ((-m24_kbd->y) & 0x7f);

        m24_kbd_adddata(0xfe);
        m24_kbd_adddata(m24_kbd->x);
        m24_kbd_adddata(m24_kbd->y);

        m24_kbd->x = m24_kbd->y = 0;
    } else {
        while (m24_kbd->x < -4) {
            if (((key_queue_end - key_queue_start) & 0xf) > 14)
                return (0xff);
            m24_kbd->x += 4;
            m24_kbd_adddata(m24_kbd->scan[3]);
        }
        while (m24_kbd->x > 4) {
            if (((key_queue_end - key_queue_start) & 0xf) > 14)
                return (0xff);
            m24_kbd->x -= 4;
            m24_kbd_adddata(m24_kbd->scan[4]);
        }
        while (m24_kbd->y < -4) {
            if (((key_queue_end - key_queue_start) & 0xf) > 14)
                return (0xff);
            m24_kbd->y += 4;
            m24_kbd_adddata(m24_kbd->scan[5]);
        }
        while (m24_kbd->y > 4) {
            if (((key_queue_end - key_queue_start) & 0xf) > 14)
                return (0xff);
            m24_kbd->y -= 4;
            m24_kbd_adddata(m24_kbd->scan[6]);
        }
    }

    return (0);
}

static void
m24_kbd_init(m24_kbd_t *kbd)
{

    /* Initialize the keyboard. */
    io_sethandler(0x0060, 2,
                  m24_kbd_read, NULL, NULL, m24_kbd_write, NULL, NULL, kbd);
    io_sethandler(0x0064, 1,
                  m24_kbd_read, NULL, NULL, m24_kbd_write, NULL, NULL, kbd);
    keyboard_send = m24_kbd_adddata_ex;
    m24_kbd_reset(kbd);
    timer_add(&kbd->send_delay_timer, m24_kbd_poll, kbd, 1);

    /* Tell mouse driver about our internal mouse. */
    mouse_reset();
    mouse_set_buttons(2);
    mouse_set_poll(ms_poll, kbd);

    keyboard_set_table(scancode_xt);
    keyboard_set_is_amstrad(0);
}

static void
m19_vid_out(uint16_t addr, uint8_t val, void *priv)
{
    m19_vid_t *vid     = (m19_vid_t *) priv;
    int        oldmode = vid->mode;

    /* activating plantronics mode */
    if (addr == 0x3dd) {
        /* already in graphics mode */
        if ((val & 0x30) && (vid->ogc.cga.cgamode & 0x2))
            vid->mode = PLANTRONICS_MODE;
        else
            vid->mode = OLIVETTI_OGC_MODE;
        /* setting graphics mode */
    } else if (addr == 0x3d8) {
        if ((val & 0x2) && (vid->colorplus.control & 0x30))
            vid->mode = PLANTRONICS_MODE;
        else
            vid->mode = OLIVETTI_OGC_MODE;
    }
    /* video mode changed */
    if (oldmode != vid->mode) {
        /* activate Plantronics emulation */
        if (vid->mode == PLANTRONICS_MODE) {
            timer_disable(&vid->ogc.cga.timer);
            timer_set_delay_u64(&vid->colorplus.cga.timer, 0);
            /* return to OGC mode */
        } else {
            timer_disable(&vid->colorplus.cga.timer);
            timer_set_delay_u64(&vid->ogc.cga.timer, 0);
        }

        colorplus_recalctimings(&vid->colorplus);
        ogc_recalctimings(&vid->ogc);
    }

    colorplus_out(addr, val, &vid->colorplus);
    ogc_out(addr, val, &vid->ogc);
}

static uint8_t
m19_vid_in(uint16_t addr, void *priv)
{
    m19_vid_t *vid = (m19_vid_t *) priv;

    if (vid->mode == PLANTRONICS_MODE)
        return colorplus_in(addr, &vid->colorplus);
    else
        return ogc_in(addr, &vid->ogc);
}

static uint8_t
m19_vid_read(uint32_t addr, void *priv)
{
    m19_vid_t *vid = (m19_vid_t *) priv;

    vid->colorplus.cga.mapping = vid->ogc.cga.mapping;
    if (vid->mode == PLANTRONICS_MODE)
        return colorplus_read(addr, &vid->colorplus);
    else
        return ogc_read(addr, &vid->ogc);
}

static void
m19_vid_write(uint32_t addr, uint8_t val, void *priv)
{
    m19_vid_t *vid = (m19_vid_t *) priv;

    colorplus_write(addr, val, &vid->colorplus);
    ogc_write(addr, val, &vid->ogc);
}

static void
m19_vid_close(void *priv)
{
    m19_vid_t *vid = (m19_vid_t *) priv;

    free(vid->ogc.cga.vram);
    free(vid->colorplus.cga.vram);
    free(vid);
}

static void
m19_vid_speed_changed(void *priv)
{
    m19_vid_t *vid = (m19_vid_t *) priv;

    colorplus_recalctimings(&vid->colorplus);
    ogc_recalctimings(&vid->ogc);
}

static void
m19_vid_init(m19_vid_t *vid)
{
    device_context(&m19_vid_device);

    /* int display_type; */
    vid->mode = OLIVETTI_OGC_MODE;

    video_inform(VIDEO_FLAG_TYPE_CGA, &timing_m19_vid);

    /* display_type = device_get_config_int("display_type"); */

    /* OGC emulation part begin */
    loadfont_ex("roms/machines/m19/BIOS.BIN", 1, 90);
    /* composite is not working yet */
    vid->ogc.cga.composite    = 0; // (display_type != CGA_RGB);
    vid->ogc.cga.revision     = device_get_config_int("composite_type");
    vid->ogc.cga.snow_enabled = device_get_config_int("snow_enabled");

    vid->ogc.cga.vram = malloc(0x8000);

    /* cga_comp_init(vid->ogc.cga.revision); */

    vid->ogc.cga.rgb_type = device_get_config_int("rgb_type");
    cga_palette           = (vid->ogc.cga.rgb_type << 1);
    cgapal_rebuild();
    ogc_mdaattr_rebuild();

    /* color display */
    if (device_get_config_int("rgb_type") == 0 || device_get_config_int("rgb_type") == 4)
        vid->ogc.mono_display = 0;
    else
        vid->ogc.mono_display = 1;
    /* OGC emulation part end */

    /* Plantronics emulation part begin*/
    /* composite is not working yet */
    vid->colorplus.cga.composite = 0; //(display_type != CGA_RGB);
    /* vid->colorplus.cga.snow_enabled = device_get_config_int("snow_enabled"); */

    vid->colorplus.cga.vram = malloc(0x8000);

    /* vid->colorplus.cga.cgamode = 0x1; */
    /* Plantronics emulation part end*/

    timer_add(&vid->ogc.cga.timer, ogc_poll, &vid->ogc, 1);
    timer_add(&vid->colorplus.cga.timer, colorplus_poll, &vid->colorplus, 1);
    timer_disable(&vid->colorplus.cga.timer);
    mem_mapping_add(&vid->ogc.cga.mapping, 0xb8000, 0x08000, m19_vid_read, NULL, NULL, m19_vid_write, NULL, NULL, NULL, MEM_MAPPING_EXTERNAL, vid);
    io_sethandler(0x03d0, 0x0010, m19_vid_in, NULL, NULL, m19_vid_out, NULL, NULL, vid);

    vid->mode = OLIVETTI_OGC_MODE;

    device_context_restore();
}

const device_t m24_kbd_device = {
    .name          = "Olivetti M24 keyboard and mouse",
    .internal_name = "m24_kbd",
    .flags         = 0,
    .local         = 0,
    .init          = NULL,
    .close         = m24_kbd_close,
    .reset         = m24_kbd_reset,
    { .available = NULL },
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};

const device_config_t m19_vid_config[] = {
  // clang-format off
    {
        /* Olivetti / ATT compatible displays */
        .name = "rgb_type",
        .description = "RGB type",
        .type = CONFIG_SELECTION,
        .default_string = "",
        .default_int = CGA_RGB,
        .file_filter = "",
        .spinner = { 0 },
        .selection = {
            { .description = "Color",            .value = 0 },
            { .description = "Green Monochrome", .value = 1 },
            { .description = "Amber Monochrome", .value = 2 },
            { .description = "Gray Monochrome",  .value = 3 },
            { .description = ""                             }
        }
    },
    {
        .name = "snow_enabled",
        .description = "Snow emulation",
        .type = CONFIG_BINARY,
        .default_string = "",
        .default_int = 1,
    },
    { .name = "", .description = "", .type = CONFIG_END }
  // clang-format on
};

const device_t m19_vid_device = {
    .name          = "Olivetti M19 graphics card",
    .internal_name = "m19_vid",
    .flags         = 0,
    .local         = 0,
    .init          = NULL,
    .close         = m19_vid_close,
    .reset         = NULL,
    { .available = NULL },
    .speed_changed = m19_vid_speed_changed,
    .force_redraw  = NULL,
    .config        = m19_vid_config
};

static uint8_t
m24_read(uint16_t port, void *priv)
{
    uint8_t ret = 0x00;
    int     i, fdd_count = 0;

    switch (port) {
        /*
         * port 66:
         * DIPSW-0 on mainboard (off=present=1)
         * bit 7 - 2764 (off) / 2732 (on) ROM (BIOS < 1.36)
         * bit 7 - Use (off) / do not use (on) memory bank 1 (BIOS >= 1.36)
         * bit 6 - n/a
         * bit 5 - 8530 (off) / 8250 (on) SCC
         * bit 4 - 8087 present
         * bits 3-0 - installed memory
         */
        case 0x66:
            /* Switch 5 - 8087 present */
            if (hasfpu)
                ret |= 0x10;
            /*
             * Switches 1, 2, 3, 4 - installed memory
             * Switch 8 - Use memory bank 1
             */
            switch (mem_size) {
                case 128:
                    ret |= 0x1;
                    break;
                case 256:
                    ret |= 0x2;
                    break;
                case 384:
                    ret |= 0x1 | 0x2 | 0x80;
                    break;
                case 512:
                    ret |= 0x8;
                    break;
                case 640:
                    ret |= 0x1 | 0x8 | 0x80;
                    break;
                default:
                    break;
            }
            break;
        /*
         * port 67:
         * DIPSW-1 on mainboard (off=present=1)
         * bits 7-6 - number of drives
         * bits 5-4 - display adapter
         * bit 3 - video scroll CPU (on) / slow scroll (off)
         * bit 2 - BIOS HD on mainboard (on) / on controller (off)
         * bit 1 - FDD fast (off) / slow (on) start drive
         * bit 0 - 96 TPI (720 KB 3.5") (off) / 48 TPI (360 KB 5.25") FDD drive
         *
         * Display adapter:
         * off off 80x25 mono
         * off on  40x25 color
         * on off  80x25 color
         * on on   EGA/VGA (works only for BIOS ROM 1.43)
         */
        case 0x67:
            for (i = 0; i < FDD_NUM; i++) {
                if (fdd_get_flags(i))
                    fdd_count++;
            }

            /* Switches 7, 8 - floppy drives. */
            if (!fdd_count)
                ret |= 0x00;
            else
                ret |= ((fdd_count - 1) << 6);

            /* Switches 5, 6 - monitor type */
            if (video_is_mda())
                ret |= 0x30;
            else if (video_is_cga())
                ret |= 0x20; /* 0x10 would be 40x25 */
            else
                ret |= 0x0;

            /* Switch 3 - Disable internal BIOS HD */
            ret |= 0x4;

            /* Switch 2 - Set fast startup */
            ret |= 0x2;
            
            break;
    }

    return (ret);
}

int
machine_xt_m24_init(const machine_t *model)
{
    int        ret;
    m24_kbd_t *m24_kbd;
    nvr_t     *nvr;

    ret = bios_load_interleaved("roms/machines/m24/olivetti_m24_bios_version_1.44_low_even.bin",
                                "roms/machines/m24/olivetti_m24_bios_version_1.44_high_odd.bin",
                                0x000fc000, 16384, 0);

    if (bios_only || !ret)
        return ret;

    m24_kbd = (m24_kbd_t *) malloc(sizeof(m24_kbd_t));
    memset(m24_kbd, 0x00, sizeof(m24_kbd_t));

    machine_common_init(model);

    /* On-board FDC can be disabled only on M24SP */
    if (fdc_type == FDC_INTERNAL)
        device_add(&fdc_xt_device);

    /* Address 66-67 = mainboard dip-switch settings */
    io_sethandler(0x0066, 2, m24_read, NULL, NULL, NULL, NULL, NULL, NULL);

    standalone_gameport_type = &gameport_device;

    nmi_init();

    /* Allocate an NVR for this machine. */
    nvr = (nvr_t *) malloc(sizeof(nvr_t));
    if (nvr == NULL)
        return (0);
    memset(nvr, 0x00, sizeof(nvr_t));

    mm58174_init(nvr, model->nvrmask + 1);

    video_reset(gfxcard);

    if (gfxcard == VID_INTERNAL)
        device_add(&ogc_m24_device);

    m24_kbd_init(m24_kbd);
    device_add_ex(&m24_kbd_device, m24_kbd);

    return ret;
}

/*
 * Current bugs:
 * - handles only 360kb floppy drives (drive type and capacity selectable with jumpers mapped to unknown memory locations)
 */
int
machine_xt_m240_init(const machine_t *model)
{
    int ret;
    nvr_t     *nvr;

    ret = bios_load_interleaved("roms/machines/m240/olivetti_m240_pch6_2.04_low.bin",
                                "roms/machines/m240/olivetti_m240_pch5_2.04_high.bin",
                                0x000f8000, 32768, 0);

    if (bios_only || !ret)
        return ret;

    machine_common_init(model);

    pit_devs[0].set_out_func(pit_devs[0].data, 1, pit_refresh_timer_xt);

    /* Address 66-67 = mainboard dip-switch settings */
    io_sethandler(0x0066, 2, m24_read, NULL, NULL, NULL, NULL, NULL, NULL);

    /*
     * port 60: should return jumper settings only under unknown conditions
     * SWB on mainboard (off=1)
     * bit 7 - use BIOS HD on mainboard (on) / on controller (off)
     * bit 6 - use OCG/CGA display adapter (on) / other display adapter (off)
     */
    device_add(&keyboard_at_olivetti_device);
    device_add(&port_6x_olivetti_device);

    if (fdc_type == FDC_INTERNAL)
        device_add(&fdc_xt_device);

    if (joystick_type)
        device_add(&gameport_device);

    nmi_init();

    /* Allocate an NVR for this machine. */
    nvr = (nvr_t *) malloc(sizeof(nvr_t));
    if (nvr == NULL)
        return (0);
    memset(nvr, 0x00, sizeof(nvr_t));

    mm58274_init(nvr, model->nvrmask + 1);

    if (hdc_current == HDC_INTERNAL)
        device_add(&st506_xt_wd1002a_wx1_nobios_device);

    return ret;
}

/*
 * Current bugs:
 * - 640x400x2 graphics mode not supported (bit 0 of register 0x3de cannot be set)
 * - optional mouse emulation missing
 * - setting CPU speed at 4.77MHz sometimes throws a timer error. If the machine is hard-resetted, the error disappears.
 */
int
machine_xt_m19_init(const machine_t *model)
{
    int ret;

    ret = bios_load_linear("roms/machines/m19/BIOS.BIN",
                           0x000fc000, 16384, 0);

    if (bios_only || !ret)
        return ret;

    m19_vid_t *vid;

    /* Do not move memory allocation elsewhere. */
    vid = (m19_vid_t *) malloc(sizeof(m19_vid_t));
    memset(vid, 0x00, sizeof(m19_vid_t));

    machine_common_init(model);

    pit_devs[0].set_out_func(pit_devs[0].data, 1, pit_refresh_timer_xt);

    /* On-board FDC cannot be disabled */
    device_add(&fdc_xt_device);

    nmi_init();

    video_reset(gfxcard);

    m19_vid_init(vid);
    device_add_ex(&m19_vid_device, vid);

    device_add(&keyboard_xt_olivetti_device);

    pit_set_clock(14318184.0);

    return ret;
}