#include <hidapi/hidapi.h>
#include <wchar.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define TARGET_DEVICE L"USBRelay2"

#define RELAY_OFF 0xfd
#define RELAY_ON  0xff

int main(int argc, char *argv[])
{
  struct hid_device_info *hidinfo;
  hid_device *hiddev;
  unsigned char buf[8];
  int result, relay_number, relay_operation;

  hidinfo = hid_enumerate(0, 0);
  while (hidinfo != NULL) {
    if (0 == wcscmp(hidinfo->product_string, TARGET_DEVICE)) {
      break;
    }
    hidinfo = hidinfo->next;
  }

  if (hidinfo == NULL) {
    fprintf(stderr, "Did not find '%ls' in USB devices!\n", TARGET_DEVICE);
    return 1;
  }

  hiddev = hid_open_path(hidinfo->path);
  if (hiddev == NULL) {
    fprintf(stderr, "hid_open_path() failed on: %s\n", hidinfo->path);
    return 1;
  }

  if (argc > 2) {
    relay_number = atoi(argv[1]) & 0b11; /* Limit to 2 relays. */
    relay_operation = 0;
    if (0 == strcasecmp(argv[2], "on")) {
      relay_operation = RELAY_ON;
    } else if (0 == strcasecmp(argv[2], "off")) {
      relay_operation = RELAY_OFF;
    } else {
      fprintf(stderr, "Invalid relay operation\n");
      hid_close(hiddev);
      return 1;
    }

    memset(buf, 0x00, sizeof(buf));
    buf[0] = 0x00;
    buf[1] = relay_operation;
    buf[2] = relay_number;
    result = hid_write(hiddev, buf, sizeof(buf));
    if (result == -1) {
      fprintf(stderr, "hid_write() failed!\n");
      hid_close(hiddev);
      return 1;
    }
  }

  buf[0] = 0x01;
  result = hid_get_feature_report(hiddev, buf, sizeof(buf));
  if (result == -1) {
    fprintf(stderr, "hid_get_feature_report() failed!\n");
    hid_close(hiddev);
    return 1;
  }

  printf("Relay #1: %d\n",  buf[7] & 0b01);
  printf("Relay #2: %d\n", (buf[7] & 0b10) >> 1);
  printf("Usage: %s <relay number> <on|off>\n", argv[0]);

  hid_close(hiddev);
  return 0;
}
          

dd if=/dev/zero of=Toshiba_DOS.dd bs=512 count=1592568
          

qemu-system-i386 -drive format=raw,file=Toshiba.dd -cpu pentium -m 32 -monitor stdio -fda DOS_Floppy_1.dd
          

change floppy0 DOS_Floppy_2.dd
change floppy0 DOS_Floppy_3.dd
eject floppy0
          

sudo mount -o loop,offset=32256 Toshiba_DOS.dd /mnt/loop/
          

dd if=Toshiba_DOS.dd of=/dev/sdd bs=512 status=progress
          

C:\DOS\SMARTDRV.EXE /X
@ECHO OFF
PROMPT $p$g
PATH C:\DOS;C:\VI;C:\MSKERMIT;C:\PKZIP
SET TEMP=C:\DOS
MODE CON CODEPAGE PREPARE=((850) C:\DOS\EGA.CPI)
MODE CON CODEPAGE SELECT=850
LOADHIGH=C:\DOS\KEYB NO,,C:\DOS\KEYBOARD.SYS
LOADHIGH=C:\DOS\DOSKEY.COM
LOADHIGH=C:\DRIVERS\MOUSE.COM
LOADHIGH=C:\DRIVERS\MSCDEX.EXE /D:MSCD001 /L:D
C:\ESSUTIL\ESSVOL.EXE /V:8 /L:8 /W:8 /M:0 /C:8 /S:8
SET BLASTER=A220 I7 D1 T6 P330 H5
          

DEVICE=C:\DOS\HIMEM.SYS
DEVICE=C:\DOS\EMM386.EXE NOEMS
DOS=HIGH,UMB
COUNTRY=047,,C:\DOS\COUNTRY.SYS
DEVICEHIGH=C:\DOS\SETVER.EXE
DEVICEHIGH=C:\DOS\DISPLAY.SYS CON=(EGA,,1)
FILES=50
BUFFERS=10,0
DEVICEHIGH=C:\DRIVERS\OAKCDROM.SYS /D:MSCD001
          

Sound: DMA (output) timed out - IRQ/DRQ config error?
          

tar -xvzf linux-2.0.35.tar.gz
gunzip 2.0.36-pre-patch-14.gz
gunzip sound.diff.gz
patch -p0 < 2.0.36-pre-patch-14
patch -p0 < sound.diff
mv linux linux-2.0.36
patch -p0 < kernel-2.0.36-sound-new.patch
cp kernel-2.0.36-i386.config linux-2.0.36/.config
          

--- ad1848.c.orig    2020-08-30 12:42:45.362175159 +0200
+++ ad1848.c    2020-08-30 12:42:52.142175232 +0200
@@ -37,6 +37,9 @@
 
 #include "soundmodule.h"
 
+#define DEBUGXL
+#define DDB
+
 #define DEB(x)
 #define DEB1(x)
 #include "sound_config.h"
@@ -1532,10 +1535,19 @@
     {
         if ((tmp1 = ad_read(devc, i)) != (tmp2 = ad_read(devc, i + 16)))
         {
-            DDB(printk("ad1848 detect step F(%d/%x/%x) - OPTi chip???\n", i, tmp1, tmp2));
-            if (!ad1847_flag)
-                optiC930 = 1;
-            break;
+            if (deskpro_xl)
+            {
+                DDB(printk("Deskpro XL, so assuming AD1847\n"));
+                ad1847_flag = 1;
+                break;
+            }
+            else
+            {
+                DDB(printk("ad1848 detect step F(%d/%x/%x) - OPTi chip???\n", i, tmp1, tmp2));
+                if (!ad1847_flag)
+                    optiC930 = 1;
+                break;
+            }
         }
     }
 
@@ -1688,7 +1700,10 @@
                         }
                         else
                         {
-                            devc->model = MD_4231;
+                            if (! deskpro_xl)
+                            {
+                                devc->model = MD_4231;
+                            }
                         }
                 }
             }
@@ -1708,6 +1723,7 @@
     if (devc->model == MD_1848 && ad1847_flag)
         devc->chip_name = "AD1847";
 
+    DDB(printk("ad1848_detect() - '%s' (%d)\n", devc->chip_name, devc->model));
 
     return 1;
 }
          

alias sound ad1848
alias midi opl3
options opl3 io=0x388
options ad1848 io=0x530 irq=9 dma=1,0 type=2 deskpro_xl=1
          

#!/bin/bash
set -e

TARGET="i386-linux-uclibc"
PREFIX="${HOME}/opt/gcc-${TARGET}/"
SYSROOT="${PREFIX}/${TARGET}/sysroot"

GCC_SRC="gcc-3.4.6.tar.bz2"
BINUTILS_SRC="binutils-2.32.tar.xz"
UCLIBC_SRC="uClibc-0.9.33.2.tar.xz"
LINUX_SRC="linux-2.4.37.11.tar.xz"
BUSYBOX_SRC="busybox-1.19.4.tar.bz2"

export PATH="${PREFIX}bin:$PATH"

# Prepare Prefix and System Root
if [ -d "$SYSROOT" ]; then
  echo "Old system root directory detected, please remove it."
  exit 1
else
  mkdir -p "$SYSROOT/usr"
fi

# Prepare Build Directories:
if [ -d build ]; then
  echo "Old build directory detected, please remove it."
  exit 1
else
  mkdir -p build/binutils
  mkdir -p build/gcc-stage1
  mkdir -p build/gcc-stage2
  mkdir -p build/uclibc
  mkdir -p build/linux
  mkdir -p build/busybox
fi

# Unpack Sources:
if [ -d source ]; then
  cd source
  tar -xvjf "$GCC_SRC"
  tar -xvJf "$BINUTILS_SRC"
  tar -xvJf "$UCLIBC_SRC" -C ../build/uclibc
  tar -xvJf "$LINUX_SRC" -C ../build/linux
  tar -xvjf "$BUSYBOX_SRC" -C ../build/busybox
  cd -
else
  echo "No source directory, please download sources."
  exit 1
fi

# Patch gcc-3.4.6:
cd "source/gcc-3.4.6/gcc/config/i386/"
if ! fgrep --silent "inhibit_libc" linux.h; then
  patch -p 0 < ../../../../../gcc-3.4.6-linux.h.patch
fi
cd -

# Patch linux-2.4.37.11:
cd "build/linux/linux-2.4.37.11/include/linux/"
if ! fgrep --silent "<linux/types.h>" filter.h; then
  patch -p 0 < ../../../../../linux-2.4.37.11-filter.h.patch
fi
cd -

# Install Linux 2.4 Headers:
cd build/linux/linux-*
make ARCH=i386 mrproper
make ARCH=i386 include/linux/version.h
make ARCH=i386 symlinks
mkdir -p "$SYSROOT/usr/include/asm"
cp -v -R -H include/asm "$SYSROOT/usr/include"
cp -v -R include/asm-generic "$SYSROOT/usr/include"
cp -v -R include/linux "$SYSROOT/usr/include"
touch "${SYSROOT}/usr/include/linux/autoconf.h"
cd -

# Build binutils:
cd build/binutils
../../source/binutils-*/configure --target="$TARGET" --prefix="$PREFIX" --with-sysroot="$SYSROOT" --disable-werror --enable-languages=c,c++ --enable-shared --without-newlib --disable-libgomp --enable-fast-install=N/A
make all-{binutils,gas,ld}
make install-{binutils,ld,gas}
cd -

# Build Stage 1 GCC3:
cd build/gcc-stage1
../../source/gcc-3*/configure --target="$TARGET" --prefix="$PREFIX" --with-sysroot="$SYSROOT" --with-cpu=i386 --disable-fast-install --disable-werror --disable-multilib --enable-languages=c --without-headers --disable-shared --disable-libssp --disable-libmudflap --with-newlib --disable-c99 --disable-libgomp --disable-threads
make all-gcc
make install-gcc
cd -

# Install uClibc Headers:
cd build/uclibc/uClibc-*
cp -v ../../../config-uclibc .config
sed -i -e "s%KERNEL_HEADERS=.*%KERNEL_HEADERS=\"$SYSROOT/usr/include/\"%" .config
make ARCH=i386 PREFIX="$SYSROOT" install_headers
cd -

# Build uClibc:
cd build/uclibc/uClibc-*
make ARCH=i386 PREFIX="$SYSROOT"
make ARCH=i386 PREFIX="$SYSROOT" install
cd -

# Build Stage 2 GCC3:
cd build/gcc-stage2
../../source/gcc-3*/configure --target="$TARGET" --prefix="$PREFIX" --with-sysroot="$SYSROOT" --with-cpu=i386 --enable-fast-install=N/A --disable-werror --enable-languages=c,c++ --disable-shared --without-newlib --disable-libgomp --disable-threads
make all-gcc
make install-gcc
cd -

# Build Linux 2.4:
cd build/linux/linux-*
cp -v ../../../config-linux .config
make ARCH=i386 CROSS_COMPILE=i386-linux-uclibc- oldconfig
make ARCH=i386 CROSS_COMPILE=i386-linux-uclibc- dep
make ARCH=i386 CROSS_COMPILE=i386-linux-uclibc- bzImage
cd -

# Build Busybox:
cd build/busybox/busybox-*
cp -v ../../../config-busybox .config
make CROSS_COMPILE=i386-linux-uclibc-
cd -
          

#!/bin/bash
set -e

ROOTFS="`pwd`/rootfs/"

TARGET="i386-linux-uclibc"
PREFIX="${HOME}/opt/gcc-${TARGET}/"
SYSROOT="${PREFIX}/${TARGET}/sysroot"

export PATH="${PREFIX}bin:$PATH"

if [ -d "$ROOTFS" ]; then
  echo "Old root FS directory detected, please remove it."
  exit 1
fi
mkdir -p "$ROOTFS"

# Install Busybox:
cd build/busybox/busybox-*
make CROSS_COMPILE=i386-linux-uclibc- CONFIG_PREFIX="$ROOTFS" install
cd -

# Create some essential directories
cd "$ROOTFS"
mkdir etc
mkdir etc/init.d
mkdir lib
mkdir proc
mkdir sys
mkdir tmp
mkdir root
mkdir dev
mkdir dev/pts
cd -

# Initial rc.S:
cat > rcS <<EOF
#!/bin/sh
mount -t proc /proc /proc
mount -t devpts /dev/pts /dev/pts
mount -t tmpfs /tmp /tmp
loadkmap < /etc/no-latin1.bmap
hostname busybox
EOF
mv -v rcS "$ROOTFS/etc/init.d/"

# Initial inittab:
cat > inittab <<EOF
::sysinit:/etc/init.d/rcS
::respawn:-/bin/sh
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
::restart:/sbin/init
EOF
mv -v inittab "$ROOTFS/etc/"

# Copy this system's keymap:
loadkeys -b /usr/share/kbd/keymaps/i386/qwerty/no-latin1.map.gz > "$ROOTFS/etc/no-latin1.bmap"

# Make everything root user:
sudo chown -R root:root "$ROOTFS"

# Create some critical devices:
sudo mknod "$ROOTFS/dev/tty" c 5 0
sudo mknod "$ROOTFS/dev/console" c 5 1
sudo mknod -m 0666 "$ROOTFS/dev/null" c 1 3

# Create some useful devices:
sudo mknod "$ROOTFS/dev/rtc" c 10 135
sudo mknod "$ROOTFS/dev/tty0" c 4 0
sudo mknod "$ROOTFS/dev/tty1" c 4 1
sudo mknod "$ROOTFS/dev/tty2" c 4 2
sudo mknod "$ROOTFS/dev/tty3" c 4 3
sudo mknod "$ROOTFS/dev/ttyS0" c 4 64
sudo mknod "$ROOTFS/dev/ttyS1" c 4 65
sudo mknod "$ROOTFS/dev/fd0" b 2 0
sudo mknod "$ROOTFS/dev/fd1" b 2 1
sudo mknod "$ROOTFS/dev/root" b 4 0
sudo mknod "$ROOTFS/dev/lp0" c 6 0

# SetUID on busybox binary:
sudo chmod +s "$ROOTFS/bin/busybox"

# Make rcS executable:
sudo chmod +x "$ROOTFS/etc/init.d/rcS"

# Make Compressed ROM archive:
mkfs.cramfs rootfs rootfs.cramfs
          

qemu-system-i386 -kernel bzImage -initrd rootfs.cramfs
          

mkdir -p ~/opt/outlaws
mkdir ~/opt/outlaws/cd1 # Then copy files from CD1 into here.
mkdir ~/opt/outlaws/cd2 # Then copy files from CD2 into here.
echo "OUTLAWS_1" > ~/opt/outlaws/cd1/.windows-label
echo "OUTLAWS_2" > ~/opt/outlaws/cd2/.windows-label
ln -s "cd1" ~/opt/outlaws/drive_d
WINEARCH=win32 WINEPREFIX=~/opt/outlaws winecfg # D: = "drive_d" = CD-ROM
WINEARCH=win32 WINEPREFIX=~/opt/outlaws wine ~/opt/outlaws/drive_d/SETUP.EXE
          

--- mcicda.c.orig	2020-08-22 14:22:13.861217377 +0200
+++ mcicda.c	2020-08-22 14:22:18.323217425 +0200
@@ -20,11 +20,21 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
+#define MPLAYER_FIFO_LOCATION "/tmp/mplayer.fifo"
+#define TOC_FILE_LOCATION "/tmp/toc.txt"
+
 #include "config.h"
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <time.h>
+
 #define WIN32_NO_STATUS
 #include "windef.h"
 #include "winbase.h"
@@ -79,10 +89,211 @@
 typedef HRESULT(WINAPI*LPDIRECTSOUNDCREATE)(LPCGUID,LPDIRECTSOUND*,LPUNKNOWN);
 static LPDIRECTSOUNDCREATE pDirectSoundCreate;
 
+static int mplayer_current_track = 0;
+static int mplayer_current_min   = 0;
+static int mplayer_current_sec   = 0;
+static int mplayer_current_frame = 0;
+static struct timespec mplayer_playback_started = {0,0};
+
+static void mplayer_command(const char *command)
+{
+    int fd, written;
+
+    fd = open(MPLAYER_FIFO_LOCATION, O_NONBLOCK | O_WRONLY);
+    if (fd == -1) {
+        TRACE("No pipe\n");
+        return;
+    }
+
+    written = write(fd, command, strlen(command));
+    if (written <= 0) {
+        TRACE("Write failed\n");
+    }
+
+    close(fd);
+}
+
 static BOOL device_io(HANDLE dev, DWORD code, void *inbuffer, DWORD insize, void *outbuffer, DWORD outsize, DWORD *retsize, OVERLAPPED *overlapped)
 {
     const char *str;
-    BOOL ret = DeviceIoControl(dev, code, inbuffer, insize, outbuffer, outsize, retsize, overlapped);
+
+    int track_no, min, sec, frame;
+    BOOL ret = TRUE;
+    CDROM_TOC *toc;
+    CDROM_SUB_Q_DATA_FORMAT *qfmt;
+    SUB_Q_CHANNEL_DATA *qdata;
+    FILE *fh;
+    char buf[16];
+    struct timespec now;
+
+    *retsize = 0;
+
+    switch (code) {
+    case IOCTL_CDROM_READ_TOC:
+        toc = (CDROM_TOC *)outbuffer;
+        *retsize = CDROM_TOC_SIZE;
+
+        toc->Length[0] = 0;
+        toc->Length[1] = 0;
+        toc->FirstTrack = 1;
+        toc->LastTrack = 1;
+
+        // Set up first track as data track.
+        toc->TrackData[0].TrackNumber = 1;
+        toc->TrackData[0].Control = 0x4;
+        toc->TrackData[0].Address[1] = 0;
+        toc->TrackData[0].Address[2] = 0;
+        toc->TrackData[0].Address[3] = 0;
+
+        // Get other audio tracks from toc file.
+        fh = fopen(TOC_FILE_LOCATION, "r");
+        if (fh == NULL) {
+          TRACE("IOCTL_CDROM_READ_TOC, Failed to open: %s\n", TOC_FILE_LOCATION);
+          break;
+        }
+
+        while (fgets(buf, sizeof(buf), fh) != NULL)
+        {
+          sscanf(buf, "%02d:%02d:%02d", &min, &sec, &frame);
+
+          toc->TrackData[toc->LastTrack].TrackNumber = toc->LastTrack + 1;
+          toc->TrackData[toc->LastTrack].Control = 0;
+          toc->TrackData[toc->LastTrack].Address[1] = min;
+          toc->TrackData[toc->LastTrack].Address[2] = sec;
+          toc->TrackData[toc->LastTrack].Address[3] = frame;
+
+          toc->LastTrack++;
+
+          TRACE("IOCTL_CDROM_READ_TOC, Track %d = %02d:%02d:%02d\n", toc->LastTrack, min, sec, frame);
+        }
+
+        toc->LastTrack--; // Remove the last dummy track:
+
+        fclose(fh);
+        break;
+
+    case IOCTL_CDROM_STOP_AUDIO:
+        mplayer_command("stop\n");
+        break;
+
+    case IOCTL_CDROM_PAUSE_AUDIO:
+        mplayer_command("stop\n");
+        break;
+
+    case IOCTL_CDROM_READ_Q_CHANNEL:
+        qfmt  = (CDROM_SUB_Q_DATA_FORMAT *)inbuffer;
+        qdata = (SUB_Q_CHANNEL_DATA *)outbuffer;
+        *retsize = sizeof(SUB_Q_CHANNEL_DATA);
+
+        if (qfmt->Format == IOCTL_CDROM_CURRENT_POSITION)
+        {
+            qdata->CurrentPosition.FormatCode = IOCTL_CDROM_CURRENT_POSITION;
+            qdata->CurrentPosition.Control = 0;
+            qdata->CurrentPosition.ADR = 0;
+            qdata->CurrentPosition.TrackNumber = mplayer_current_track;
+            qdata->CurrentPosition.IndexNumber = 0;
+
+            clock_gettime(CLOCK_MONOTONIC, &now);
+            TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Started = %lu.%lu\n",
+                mplayer_playback_started.tv_sec, mplayer_playback_started.tv_nsec);
+            TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Now = %lu.%lu\n", now.tv_sec, now.tv_nsec);
+
+            min = (now.tv_sec - mplayer_playback_started.tv_sec) / 60;
+            sec = (now.tv_sec - mplayer_playback_started.tv_sec) % 60;
+            frame = (now.tv_nsec - mplayer_playback_started.tv_nsec);
+            if (frame < 0) {
+                frame = 0 - frame;
+                sec--;
+                if (sec < 0) {
+                  sec = 59;
+                  min--;
+                }
+            }
+            frame = (frame / 10000000) * 0.75;
+
+            if (mplayer_current_min > 0 ||
+                mplayer_current_sec > 0 ||
+                mplayer_current_frame > 0)
+            {
+                min += mplayer_current_min;
+                sec += mplayer_current_sec;
+                if (sec >= 60) {
+                    sec -= 60;
+                    min++;
+                }
+                frame += mplayer_current_frame;
+                if (frame >= 76) {
+                    frame -= 76;
+                    sec++;
+                    if (sec >= 60) {
+                        sec -= 60;
+                        min++;
+                    }
+                }
+            }
+
+            qdata->CurrentPosition.TrackRelativeAddress[0] = 0;
+            qdata->CurrentPosition.TrackRelativeAddress[1] = min;
+            qdata->CurrentPosition.TrackRelativeAddress[2] = sec;
+            qdata->CurrentPosition.TrackRelativeAddress[3] = frame;
+
+            qdata->CurrentPosition.AbsoluteAddress[0] = 0;
+            qdata->CurrentPosition.AbsoluteAddress[1] = min;
+            qdata->CurrentPosition.AbsoluteAddress[2] = sec;
+            qdata->CurrentPosition.AbsoluteAddress[3] = frame;
+
+            fh = fopen(TOC_FILE_LOCATION, "r");
+            if (fh == NULL) {
+              TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Failed to open: %s\n", TOC_FILE_LOCATION);
+              break;
+            }
+
+            track_no = 2;
+            while (fgets(buf, sizeof(buf), fh) != NULL)
+            {
+                if (track_no == mplayer_current_track) {
+                    sscanf(buf, "%02d:%02d:%02d", &min, &sec, &frame);
+                    qdata->CurrentPosition.AbsoluteAddress[1] += min;
+                    qdata->CurrentPosition.AbsoluteAddress[2] += sec;
+                    if (qdata->CurrentPosition.AbsoluteAddress[2] >= 60) {
+                        qdata->CurrentPosition.AbsoluteAddress[2] -= 60;
+                        qdata->CurrentPosition.AbsoluteAddress[1]++;
+                    }
+                    qdata->CurrentPosition.AbsoluteAddress[3] += frame;
+                    if (qdata->CurrentPosition.AbsoluteAddress[3] >= 76) {
+                        qdata->CurrentPosition.AbsoluteAddress[3] -= 76;
+                        qdata->CurrentPosition.AbsoluteAddress[2]++;
+                        if (qdata->CurrentPosition.AbsoluteAddress[2] >= 60) {
+                            qdata->CurrentPosition.AbsoluteAddress[2] -= 60;
+                            qdata->CurrentPosition.AbsoluteAddress[1]++;
+                        }
+                    }
+                    break;
+                }
+                track_no++;
+            }
+
+            fclose(fh);
+
+            TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Current Track = %d\n", mplayer_current_track);
+            TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Rel Pos = %02d:%02d:%02d\n",
+                qdata->CurrentPosition.TrackRelativeAddress[1],
+                qdata->CurrentPosition.TrackRelativeAddress[2],
+                qdata->CurrentPosition.TrackRelativeAddress[3]);
+            TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Abs Pos = %02d:%02d:%02d\n",
+                qdata->CurrentPosition.AbsoluteAddress[1],
+                qdata->CurrentPosition.AbsoluteAddress[2],
+                qdata->CurrentPosition.AbsoluteAddress[3]);
+        }
+        else
+        {
+           TRACE("IOCTL_CDROM_READ_Q_CHANNEL, Unknown format: %d\n", qfmt->Format);
+        }
+        break;
+
+    default:
+        break;
+    }
 
 #define XX(x) case (x): str = #x; break
     switch (code)
@@ -906,6 +1117,9 @@
     SUB_Q_CHANNEL_DATA          data;
     CDROM_TOC			toc;
 
+    int track_no, min, sec, frame;
+    char command[PATH_MAX];
+
     TRACE("(%04X, %08X, %p);\n", wDevID, dwFlags, lpParms);
 
     if (lpParms == NULL)
@@ -914,6 +1128,35 @@
     if (wmcda == NULL)
 	return MCIERR_INVALID_DEVICE_ID;
 
+    mplayer_command("stop\n");
+
+    track_no = MCI_TMSF_TRACK(lpParms->dwFrom);
+    min      = MCI_TMSF_MINUTE(lpParms->dwFrom);
+    sec      = MCI_TMSF_SECOND(lpParms->dwFrom);
+    frame    = MCI_TMSF_FRAME(lpParms->dwFrom);
+    TRACE("Track no: %d (%02d:%02d:%02d)\n", track_no, min, sec, frame);
+
+    snprintf(command, PATH_MAX, "loadfile track%02d.flac\n", track_no);
+    mplayer_command(command);
+
+    mplayer_current_track = track_no;
+    clock_gettime(CLOCK_MONOTONIC, &mplayer_playback_started);
+
+    if (min > 0 || sec > 0 || frame > 0) {
+      mplayer_current_min = min;
+      mplayer_current_sec = sec;
+      mplayer_current_frame = frame;
+
+      sec += (min * 60);
+      frame *= 1.333333;
+      TRACE("Seek to: %d.%02d\n", sec, frame);
+
+      snprintf(command, PATH_MAX, "seek %d.%02d 2\n", sec, frame);
+      mplayer_command(command);
+    }
+
+    return 0; // Because of hijacking, this ends here.
+
     if (!MCICDA_ReadTOC(wmcda, &toc, &br))
         return MCICDA_GetError(wmcda);
          

#!/bin/sh
export WINEPREFIX=~/opt/outlaws

MPLAYER_FIFO=/tmp/mplayer.fifo
TOC_FILE=/tmp/toc.txt
MPLAYER_PID_FILE=/tmp/mplayer.pid

function mplayer_stop {
  if [ -f "$MPLAYER_PID_FILE" ]; then
    kill `cat "$MPLAYER_PID_FILE"`
    rm -f "$MPLAYER_PID_FILE"
  fi
  rm -f "$MPLAYER_FIFO"
}

function mplayer_start {
  if [ ! -p "$MPLAYER_FIFO" ]; then
    mkfifo "$MPLAYER_FIFO"
  fi
  cd "${WINEPREFIX}/drive_d"
  mplayer -vo null -idle -slave -input file=$MPLAYER_FIFO 1&>/dev/null &
  echo "$!" > "$MPLAYER_PID_FILE"
  cd -
}

CD_NO="0"
while [ "$CD_NO" != "1" ] && [ "$CD_NO" != "2" ]; do
  read -p "CD number? [1 or 2] " CD_NO
done

MODE="0"
while [ "$MODE" != "g" ] && [ "$MODE" != "c" ]; do
  read -p "Start [g]ame or [c]hange CD only? " MODE
done

mplayer_stop

rm -f "${WINEPREFIX}/drive_d"
ln -s "cd$CD_NO" "${WINEPREFIX}/drive_d"
cp "${WINEPREFIX}/drive_d/toc.txt" "$TOC_FILE"

mplayer_start

if [ "$MODE" == "c" ]; then
  # If only changing CD, exit now.
  exit 0
fi

(cd "${WINEPREFIX}/drive_c/Program Files/LucasArts/Outlaws" && WINEARCH=win32 wine OLWIN.EXE)

mplayer_stop
rm -f "$TOC_FILE"
          

00:00:00
03:16:64
07:34:64
11:23:01
15:13:33
19:58:24
23:39:66
27:15:61
          

00:00:00
04:42:15
10:16:03
13:41:47
20:55:08
24:58:10
30:09:45
33:50:23
36:16:17
          

1 data 233,157,0,184,192,7,142,192,49,219,184,1,2,185,1,0,49,210
2 data 205,19,234,0,124,0,0,251,128,250,0,117,90,128,252,2,116,5
3 data 128,252,3,117,74,83,81,82,80,80,80,232,76,0,136,224,232,71
4 data 0,136,200,232,66,0,136,232,232,61,0,136,208,232,56,0,136,240
5 data 232,51,0,90,48,246,184,0,2,247,226,137,193,88,128,252,3,116
6 data 11,232,49,0,38,136,7,67,226,247,235,9,38,138,7,232,18,0
7 data 67,226,247,88,90,89,91,48,228,248,202,2,0,234,121,0,121,0
8 data 82,186,248,3,238,186,253,3,236,36,32,132,192,116,249,90,195,82
9 data 186,250,3,236,36,14,60,4,117,246,186,248,3,236,90,195,186,251
10 data 3,236,12,128,238,186,248,3,176,12,238,186,249,3,176,0,238,186
11 data 251,3,236,36,127,238,186,250,3,176,6,238,186,251,3,176,3,238
12 data 186,249,3,236,12,1,238,49,192,142,216,250,232,0,0,88,91,45
13 data 210,0,137,198,184,48,0,142,192,191,0,0,185,157,0,46,138,4
14 data 38,136,5,70,71,226,246,62,161,76,0,38,163,119,0,62,161,78
15 data 0,38,163,121,0,62,199,6,76,0,22,0,62,140,6,78,0,49
16 data 192,62,163,0,4,251,180,9,176,33,183,0,179,4,185,3,0,205
17 data 16,180,0,205,22,234,0,0,48,0
99 def seg=1984:a=0:for i=0 to 297:read j:poke a+i,j:next:call a
          

stty -F /dev/ttyS0 9600 raw
          

1 data 14,7,184,227,0,153,137,215,205,20,185,19,1,180,2,205,20,158,120,249,252,170,226,245,81,195
2 def seg=256:a=65432:for i=0 to 25:read j:poke a+i,j:next:call a
          

cat sfdboot.bin > /dev/ttyS0
          

./serialfd -d /dev/ttyS0 -a floppy.img
          

org 0x0 ; Position independent.
bits 16
cpu 8086

COM1_BASE equ 0x3f8
COM1_THR  equ COM1_BASE + 0 ; Transmitter Holding Buffer
COM1_RBR  equ COM1_BASE + 0 ; Receiver Buffer
COM1_IER  equ COM1_BASE + 1 ; Interrupt Enable Register
COM1_FCR  equ COM1_BASE + 2 ; FIFO Control Register
COM1_IIR  equ COM1_BASE + 2 ; Interrupt Identification Register
COM1_LCR  equ COM1_BASE + 3 ; Line Control Register
COM1_LSR  equ COM1_BASE + 5 ; Line Status Register
COM1_DLL  equ COM1_BASE + 0 ; Divisor Latch Low Byte
COM1_DLH  equ COM1_BASE + 1 ; Divisor Latch High Byte

RESIDENT_SEGMENT equ 0x0030 ; Bootstrap stack area.

section .text
start:
  jmp main

resident_code_start:
  ; Setup ES:BX to point at bootloader address 07C0:0
  mov ax, 0x07C0
  mov es, ax
  xor bx, bx

  ; Read VBR into bootloader memory area:
  mov ax, 0x0201
  mov cx, 0x0001
  xor dx, dx
  int 0x13

  ; Jump to bootloader:
  jmp 0x0:0x7C00

int13_interrupt:
  ; Allow other interrupts:
  sti

  ; Check if accessing drive 0 (A:)
  ; If not, then jump to original interrupt instead.
  cmp dl, 0
  jne original_int13

  ; Only operation 0x02 (Read) and 0x03 (Write) are forwarded.
  ; The rest are bypassed directly and returns OK.
  cmp ah, 2
  je _int13_interrupt_ah_ok
  cmp ah, 3
  jne _int13_interrupt_end
_int13_interrupt_ah_ok:

  ; Save registers:
  push bx
  push cx
  push dx

  ; Save sectors and operation information on stack for use later:
  push ax
  push ax
  push ax

  ; Register AL already set.
  call com_port_send
  mov al, ah
  call com_port_send
  mov al, cl
  call com_port_send
  mov al, ch
  call com_port_send
  mov al, dl
  call com_port_send
  mov al, dh
  call com_port_send

  ; Retrieve sector information (stack AL) into DL register:
  pop dx
  xor dh, dh

  mov ax, 512
  mul dx ; DX:AX = AX * DX
  mov cx, ax

  ; Determine receive (Read) or send (Write) from operation (stack AH):
  pop ax
  cmp ah, 3
  je _int13_interrupt_send_loop

_int13_interrupt_recv_loop:
  call com_port_recv
  mov [es:bx], al
  inc bx
  loop _int13_interrupt_recv_loop
  jmp _int13_loop_done

_int13_interrupt_send_loop:
  mov al, [es:bx]
  call com_port_send
  inc bx
  loop _int13_interrupt_send_loop

_int13_loop_done:

  ; Retrieve sector information (stack AL) as sectors handled:
  pop ax

  ; Restore registers:
  pop dx
  pop cx
  pop bx

_int13_interrupt_end:
  ; AL register will have same value as upon entering routine.
  xor ah, ah ; Code 0 (No Error)
  clc ; Clear error bit.
  retf 2

original_int13:
  jmp original_int13:original_int13 ; Will be overwritten runtime!

; Send contents from AL on COM1 port:
com_port_send:
  push dx
  mov dx, COM1_THR
  out dx, al
  mov dx, COM1_LSR
_com_port_send_wait:
  in al, dx
  and al, 0b00100000 ; Empty Transmit Holding Register
  test al, al
  jz _com_port_send_wait
  pop dx
  ret

; Return contents in AL on COM1 port:
com_port_recv:
  push dx
_com_port_recv_wait:
  mov dx, COM1_IIR
  in al, dx
  and al, 0b00001110 ; Identification
  cmp al, 0b00000100 ; Enable Received Data Available Interrupt
  jne _com_port_recv_wait
  mov dx, COM1_RBR
  in al, dx
  pop dx
  ret

resident_code_end:

main:
  ; Set Baudrate on COM1 to 9600, divisor = 12:
  mov dx, COM1_LCR
  in al, dx
  or al, 0b10000000 ; Set Divisor Latch Access Bit (DLAB).
  out dx, al

  mov dx, COM1_DLL
  mov al, 0xc
  out dx, al
  
  mov dx, COM1_DLH
  mov al, 0
  out dx, al

  mov dx, COM1_LCR
  in al, dx
  and al, 0b01111111 ; Reset Divisor Latch Access Bit (DLAB).
  out dx, al

  ; Disable and clear FIFO on COM1, to put it in 8250 compatibility mode:
  mov dx, COM1_FCR
  mov al, 0b00000110 ; Clear both FIFOs.
  out dx, al
  ; NOTE: Not tested what happens if this is run on an actual 8250 chip...

  ; Set mode on COM1 to 8 data bits, no parity and 1 stop bit:
  mov dx, COM1_LCR
  mov al, 0b00000011 ; 8-N-1
  out dx, al

  ; Enable interrupt bit on COM1:
  mov dx, COM1_IER
  in al, dx
  or al, 0b00000001 ; Enable Received Data Available Interrupt
  out dx, al

  ; Interact directly with IVT:
  xor ax, ax
  mov ds, ax ; Data Segment now 0000
  cli ; Disable Interrupts

  call get_ip
get_ip:
  pop ax ; IP
  pop bx ; CS
  sub ax, (get_ip - resident_code_start)
  mov si, ax ; "resident_code_start" now in SI.

  ; Copy the code to a new resident area using CS:SI -> ES:DI
  mov ax, RESIDENT_SEGMENT
  mov es, ax
  mov di, 0
  mov cx, (resident_code_end - resident_code_start)
_copy_to_resident_area:
  mov byte al, [cs:si]
  mov byte [es:di], al
  inc si
  inc di
  loop _copy_to_resident_area

  ; Save old interrupt handler:
  ; ES = RESIDENT_SEGMENT
  mov ax, [ds:0x4c]
  mov word [es:original_int13 - resident_code_start + 1], ax
  mov ax, [ds:0x4e]
  mov word [es:original_int13 - resident_code_start + 3], ax

  ; Overwrite with new interrupt handler:
  ; ES = RESIDENT_SEGMENT
  mov word [ds:0x4c], (int13_interrupt - resident_code_start)
  mov word [ds:0x4e], es

  ; Zero out COM1 port address in BDA to avoid DOS interference:
  ; DOS can set baudrate to 2400 at startup, which will cause issues.
  xor ax, ax
  mov word [ds:0x400], ax

  sti ; Enable Interrupts

  ; Indicate on screen "Ready for Loading" after key press:
  mov ah, 0x9  ; Write character and attribute at cursor position.
  mov al, 0x21 ; Character = '!'
  mov bh, 0    ; Page Number = 0
  mov bl, 0x4  ; Color = Red
  mov cx, 0x3  ; Number of Times = 3
  int 0x10

  ; Read any key press:
  mov ah, 0x0  ; Read keystroke.
  int 0x16

  ; Jump to new resident area:
  jmp RESIDENT_SEGMENT:0
          

org 0x100
bits 16
cpu 8086

COM1_BASE equ 0x3f8
COM1_THR  equ COM1_BASE + 0 ; Transmitter Holding Buffer
COM1_RBR  equ COM1_BASE + 0 ; Receiver Buffer
COM1_IER  equ COM1_BASE + 1 ; Interrupt Enable Register
COM1_FCR  equ COM1_BASE + 2 ; FIFO Control Register
COM1_IIR  equ COM1_BASE + 2 ; Interrupt Identification Register
COM1_LCR  equ COM1_BASE + 3 ; Line Control Register
COM1_LSR  equ COM1_BASE + 5 ; Line Status Register
COM1_DLL  equ COM1_BASE + 0 ; Divisor Latch Low Byte
COM1_DLH  equ COM1_BASE + 1 ; Divisor Latch High Byte

section .text
start:
  jmp main

int13_interrupt:
  ; Allow other interrupts:
  sti

  ; Check if accessing drive 0 (A:) or drive 1 (B:)
  ; If not, then jump to original interrupt instead.
  cmp dl, 0
  je _int13_interrupt_dl_ok
  cmp dl, 1
  jne original_int13
_int13_interrupt_dl_ok:

  ; Only operation 0x02 (Read) and 0x03 (Write) are forwarded.
  ; The rest are bypassed directly and returns OK.
  cmp ah, 2
  je _int13_interrupt_ah_ok
  cmp ah, 3
  jne _int13_interrupt_end
_int13_interrupt_ah_ok:

  ; Save registers:
  push bx
  push cx
  push dx

  ; Save sectors and operation information on stack for use later:
  push ax
  push ax
  push ax

  ; Register AL already set.
  call com_port_send
  mov al, ah
  call com_port_send
  mov al, cl
  call com_port_send
  mov al, ch
  call com_port_send
  mov al, dl
  call com_port_send
  mov al, dh
  call com_port_send

  ; Retrieve sector information (stack AL) into DL register:
  pop dx
  xor dh, dh

  mov ax, 512
  mul dx ; DX:AX = AX * DX
  mov cx, ax

  ; Determine receive (Read) or send (Write) from operation (stack AH):
  pop ax
  cmp ah, 3
  je _int13_interrupt_send_loop

_int13_interrupt_recv_loop:
  call com_port_recv
  mov [es:bx], al
  inc bx
  loop _int13_interrupt_recv_loop
  jmp _int13_loop_done

_int13_interrupt_send_loop:
  mov al, [es:bx]
  call com_port_send
  inc bx
  loop _int13_interrupt_send_loop

_int13_loop_done:

  ; Retrieve sector information (stack AL) as sectors handled:
  pop ax

  ; Restore registers:
  pop dx
  pop cx
  pop bx

_int13_interrupt_end:
  ; AL register will have same value as upon entering routine.
  xor ah, ah ; Code 0 (No Error)
  clc ; Clear error bit.
  retf 2

original_int13:
  jmp original_int13:original_int13 ; Will be overwritten runtime!

; Send contents from AL on COM1 port:
com_port_send:
  push dx
  mov dx, COM1_THR
  out dx, al
  mov dx, COM1_LSR
_com_port_send_wait:
  in al, dx
  and al, 0b00100000 ; Empty Transmit Holding Register
  test al, al
  jz _com_port_send_wait
  pop dx
  ret

; Return contents in AL on COM1 port:
com_port_recv:
  push dx
_com_port_recv_wait:
  mov dx, COM1_IIR
  in al, dx
  and al, 0b00001110 ; Identification
  cmp al, 0b00000100 ; Enable Received Data Available Interrupt
  jne _com_port_recv_wait
  mov dx, COM1_RBR
  in al, dx
  pop dx
  ret

; TSR end marker:
tsr_end:

main:
  ; NOTE: No protection to prevent TSR from being loaded twice or more!

  ; Set Baudrate on COM1 to 9600, divisor = 12:
  mov dx, COM1_LCR
  in al, dx
  or al, 0b10000000 ; Set Divisor Latch Access Bit (DLAB).
  out dx, al

  mov dx, COM1_DLL
  mov al, 0xc
  out dx, al
  
  mov dx, COM1_DLH
  mov al, 0
  out dx, al

  mov dx, COM1_LCR
  in al, dx
  and al, 0b01111111 ; Reset Divisor Latch Access Bit (DLAB).
  out dx, al

  ; Disable and clear FIFO on COM1, to put it in 8250 compatibility mode:
  mov dx, COM1_FCR
  mov al, 0b00000110 ; Clear both FIFOs.
  out dx, al
  ; NOTE: Not tested what happens if this is run on an actual 8250 chip...

  ; Set mode on COM1 to 8 data bits, no parity and 1 stop bit:
  mov dx, COM1_LCR
  mov al, 0b00000011 ; 8-N-1
  out dx, al

  ; Enable interrupt bit on COM1:
  mov dx, COM1_IER
  in al, dx
  or al, 0b00000001 ; Enable Received Data Available Interrupt
  out dx, al

  ; Call DOS to get original interrupt handler:
  mov al, 0x13
  mov ah, 0x35
  int 0x21
  mov word [original_int13 + 3], es
  mov word [original_int13 + 1], bx

  ; Call DOS to set interrupt handler:
  mov al, 0x13
  mov ah, 0x25
  ; DS is already same as CS, no need to change.
  mov dx, int13_interrupt
  int 0x21

  ; Terminate and Stay Resident:
  mov dx, tsr_end
  shr dx, 1
  shr dx, 1
  shr dx, 1
  shr dx, 1
  add dx, 0x11 ; Add 0x1 for remainder and 0x10 for PSP.
  mov ax, 0x3100
  int 0x21
          

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <string.h>

#define REGISTER_AL 0
#define REGISTER_AH 1
#define REGISTER_CL 2
#define REGISTER_CH 3
#define REGISTER_DL 4
#define REGISTER_DH 5

#define SECTOR_SIZE 512
#define HEADS_PER_CYLINDER_DEFAULT 2

#define OPERATION_READ_DISK_SECTORS 0x02
#define OPERATION_WRITE_DISK_SECTORS 0x03

static uint16_t get_sectors_per_track(FILE *fh)
{
  uint16_t spt;

  fseek(fh, 24, SEEK_SET); /* Offset in Volume Boot Record. */

  if (fread(&spt, sizeof(uint16_t), 1, fh) != 1) {
    return 0; /* Error */
  }

  /* Currently handling 720K and 1.44M floppies. */
  if (spt == 9 || spt == 18) {
    return spt; /* Valid */
  }

  return 0; /* Invalid */
}

static void display_help(char *progname)
{ 
  fprintf(stderr, "Usage: %s <options>\n", progname);
  fprintf(stderr, "Options:\n"
     "  -h          Display this help and exit.\n"
     "  -d DEVICE   Use TTY DEVICE.\n"
     "  -a IMAGE    Floppy IMAGE for A:\n"
     "  -b IMAGE    Floppy IMAGE for B:\n"
     "  -H HPC      Force HPC heads per cylinder.\n"
     "  -S SPT      Force SPT sectors per track.\n"
     "  -v          Verbose debugging output.\n"
     "\n");
}

int main(int argc, char *argv[])
{
  int result = EXIT_SUCCESS;
  int i, c, arg;
  int cylinder, sector, lba;
  struct termios attr;
  unsigned char registers[6];
  int debug_output = 0;
  char *tty_device = NULL;
  int tty_fd = -1;
  FILE *fh;
  char *floppy_a_image = NULL;
  char *floppy_b_image = NULL;
  FILE *floppy_a_fh = NULL;
  FILE *floppy_b_fh = NULL;
  uint16_t floppy_a_spt = 0;
  uint16_t floppy_b_spt = 0;
  int spt = 0;
  int hpc = HEADS_PER_CYLINDER_DEFAULT;
  char *operation;

  while ((c = getopt(argc, argv, "hd:a:b:H:S:v")) != -1) {
    switch (c) {
    case 'h':
      display_help(argv[0]);
      return EXIT_SUCCESS;

    case 'd':
      tty_device = optarg;
      break;

    case 'a':
      floppy_a_image = optarg;
      break;

    case 'b':
      floppy_b_image = optarg;
      break;

    case 'H':
      hpc = atoi(optarg);
      break;

    case 'S':
      spt = atoi(optarg);
      break;

    case 'v':
      debug_output = 1;
      break;

    case '?':
    default:
      display_help(argv[0]);
      return EXIT_FAILURE;
    }
  }

  if (tty_device == NULL) {
    fprintf(stderr, "Please specify a TTY!\n");
    display_help(argv[0]);
    return EXIT_FAILURE;
  }

  if (floppy_a_image == NULL && floppy_b_image == NULL) {
    fprintf(stderr, "Please specify at least one floppy image!\n");
    display_help(argv[0]);
    return EXIT_FAILURE;
  }

  if (hpc == 0) {
    fprintf(stderr, "Invalid heads per cylinder!\n");
    return EXIT_FAILURE;
  }

  /* Open serial TTY device. */
  tty_fd = open(tty_device, O_RDWR | O_NOCTTY);
  if (tty_fd == -1) {
    fprintf(stderr, "open() on TTY device failed with errno: %d\n", errno);
    return EXIT_FAILURE;
  }

  /* Set TTY into a very raw mode. */
  memset(&attr, 0, sizeof(struct termios));
  attr.c_cflag = B9600 | CS8 | CLOCAL | CREAD;
  attr.c_cc[VMIN] = 1;

  if (tcsetattr(tty_fd, TCSANOW, &attr) == -1) {
    fprintf(stderr, "tcgetattr() on TTY device failed with errno: %d\n", errno);
    close(tty_fd);
    return EXIT_FAILURE;
  }

  /* Make sure TTY "Clear To Send" signal is set. */
  arg = TIOCM_CTS;
  if (ioctl(tty_fd, TIOCMBIS, &arg) == -1) {
    fprintf(stderr, "ioctl() on TTY device failed with errno: %d\n", errno);
    close(tty_fd);
    return EXIT_FAILURE;
  }

  /* Get information about floppy A: */
  if (floppy_a_image != NULL) {
    floppy_a_fh = fopen(floppy_a_image, "r+b");
    if (floppy_a_fh == NULL) {
      fprintf(stderr, "fopen() for floppy A: failed with errno: %d\n", errno);
      result = EXIT_FAILURE;
      goto main_end;
    }

    if (spt == 0) {
      floppy_a_spt = get_sectors_per_track(floppy_a_fh);
    } else {
      floppy_a_spt = spt;
    }
    if (floppy_a_spt == 0) {
      fprintf(stderr, "Invalid sectors per track for floppy A:\n");
      result = EXIT_FAILURE;
      goto main_end;
    }
  }

  /* Get information about floppy B: */
  if (floppy_b_image != NULL) {
    floppy_b_fh = fopen(floppy_b_image, "r+b");
    if (floppy_b_fh == NULL) {
      fprintf(stderr, "fopen() for floppy B: failed with errno: %d\n", errno);
      result = EXIT_FAILURE;
      goto main_end;
    }

    if (spt == 0) {
      floppy_b_spt = get_sectors_per_track(floppy_b_fh);
    } else {
      floppy_b_spt = spt;
    }
    if (floppy_b_spt == 0) {
      fprintf(stderr, "Invalid sectors per track for floppy B:\n");
      result = EXIT_FAILURE;
      goto main_end;
    }
  }

  /* Process input and output. */
  while (1) {
    for (i = 0; i < 6; i++) {
      if (read(tty_fd, &registers[i], sizeof(unsigned char)) != 1) {
        fprintf(stderr, "read() failed with errno: %d\n", errno);
        result = EXIT_FAILURE;
        goto main_end;
      }
    }

    if (debug_output) {
      fprintf(stderr, "AL: 0x%02x\n", registers[REGISTER_AL]);
      fprintf(stderr, "AH: 0x%02x\n", registers[REGISTER_AH]);
      fprintf(stderr, "CL: 0x%02x\n", registers[REGISTER_CL]);
      fprintf(stderr, "CH: 0x%02x\n", registers[REGISTER_CH]);
      fprintf(stderr, "DL: 0x%02x\n", registers[REGISTER_DL]);
      fprintf(stderr, "DH: 0x%02x\n", registers[REGISTER_DH]);
    }

    if (registers[REGISTER_DL] == 0x00) {
      spt = floppy_a_spt;
      fh = floppy_a_fh;
    } else if (registers[REGISTER_DL] == 0x01) {
      spt = floppy_b_spt;
      fh = floppy_b_fh;
    } else {
      fprintf(stderr, "Error: Invalid drive number: %02x\n",
        registers[REGISTER_DL]);
      result = EXIT_FAILURE;
      goto main_end;
    }

    /* CX =       ---CH--- ---CL---
     * cylinder : 76543210 98
     * sector   :            543210
     * LBA = ( ( cylinder * HPC + head ) * SPT ) + sector - 1
    */

    cylinder = ((registers[REGISTER_CL] & 0xc0) << 2)
      + registers[REGISTER_CH];
    sector = registers[REGISTER_CL] & 0x3f;
    lba = ((cylinder * hpc + registers[REGISTER_DH]) * spt) + sector - 1;

    if (debug_output) {
      fprintf(stderr, "Cylinder: %d\n", cylinder);
      fprintf(stderr, "Sector  : %d\n", sector);
      fprintf(stderr, "SPT     : %d\n", spt);
      fprintf(stderr, "HPC     : %d\n", hpc);
      fprintf(stderr, "LBA     : %d\n", lba);
      fprintf(stderr, "Offset  : 0x%x\n", lba * SECTOR_SIZE);
    } else {
      switch (registers[REGISTER_AH]) {
      case OPERATION_READ_DISK_SECTORS:
        operation = "Read";
        break;
      case OPERATION_WRITE_DISK_SECTORS:
        operation = "Write";
        break;
      default:
        operation = "Unknown";
        break;
      }
      fprintf(stderr, "%s %c: sector=%d, cylinder=%d count=%d\n",
        operation, (registers[REGISTER_DL] == 0x00) ? 'A' : 'B',
        sector, cylinder, registers[REGISTER_AL]);
    }

    if (fh != NULL) {
      if (fseek(fh, lba * SECTOR_SIZE, SEEK_SET) == -1) {
        fprintf(stderr, "fseek() failed with errno: %d\n", errno);
        result = EXIT_FAILURE;
        goto main_end;
      }
    }

    switch (registers[REGISTER_AH]) {
    case OPERATION_READ_DISK_SECTORS:
      if (debug_output) {
        fprintf(stderr, "READ SECTOR DATA:\n");
      }
      for (i = 0; i < (SECTOR_SIZE * registers[REGISTER_AL]); i++) {
        if (fh != NULL) {
          c = fgetc(fh);
        } else {
          c = 0xFF; /* Dummy data if image is not loaded. */
        }
        if (debug_output) {
          fprintf(stderr, "%02x ", c);
          if (i % 16 == 15) {
            fprintf(stderr, "\n");
          }
        }
        write(tty_fd, &c, sizeof(unsigned char));
      }
      break;

    case OPERATION_WRITE_DISK_SECTORS:
      if (debug_output) {
        fprintf(stderr, "WRITE SECTOR DATA:\n");
      }
      for (i = 0; i < (SECTOR_SIZE * registers[REGISTER_AL]); i++) {
        read(tty_fd, &c, sizeof(unsigned char));
        if (fh != NULL) {
          fputc(c, fh);
        }
        if (debug_output) {
          fprintf(stderr, "%02x ", c);
          if (i % 16 == 15) {
            fprintf(stderr, "\n");
          }
        }
      }
      if (fh != NULL) {
        fflush(fh);
      }
      break;

    default:
      fprintf(stderr, "Error: Unhandled operation: %02x\n",
        registers[REGISTER_AH]);
      result = EXIT_FAILURE;
      goto main_end;
    }
  }

main_end:
  if (tty_fd != -1) close(tty_fd);
  if (floppy_a_fh != NULL) fclose(floppy_a_fh);
  if (floppy_b_fh != NULL) fclose(floppy_b_fh);

  return result;
}
          

org 0x100
bits 16
cpu 8086

COM1_BASE equ 0x3f8
COM1_THR  equ COM1_BASE + 0 ; Transmitter Holding Buffer
COM1_RBR  equ COM1_BASE + 0 ; Receiver Buffer
COM1_IER  equ COM1_BASE + 1 ; Interrupt Enable Register
COM1_FCR  equ COM1_BASE + 2 ; FIFO Control Register
COM1_IIR  equ COM1_BASE + 2 ; Interrupt Identification Register
COM1_LCR  equ COM1_BASE + 3 ; Line Control Register
COM1_LSR  equ COM1_BASE + 5 ; Line Status Register
COM1_DLL  equ COM1_BASE + 0 ; Divisor Latch Low Byte
COM1_DLH  equ COM1_BASE + 1 ; Divisor Latch High Byte

RECV_BUFFER_SIZE equ 100 ; As per Kermit documentation.
SEND_BUFFER_SIZE equ 16 ; No packets sent from this program exceed this.
PACKET_DATA_SIZE equ 94 ; Receive buffer size - 6 fields/terminator.

section .text
start:
  ; Set Baudrate on COM1 to 9600, divisor = 12:
  mov dx, COM1_LCR
  in al, dx
  or al, 0b10000000 ; Set Divisor Latch Access Bit (DLAB)
  out dx, al

  mov dx, COM1_DLL
  mov al, 0xc
  out dx, al
  
  mov dx, COM1_DLH
  mov al, 0
  out dx, al

  mov dx, COM1_LCR
  in al, dx
  and al, 0b01111111 ; Reset Divisor Latch Access Bit (DLAB)
  out dx, al

  ; Disable and clear FIFO on COM1, to put it in 8250 compatibility mode:
  mov dx, COM1_FCR
  mov al, 0b00000110 ; Clear both FIFOs.
  out dx, al

  ; Set mode on COM1 to 8 data bits, no parity and 1 stop bit:
  mov dx, COM1_LCR
  mov al, 0b00000011 ; 8-N-1
  out dx, al

  ; Enable interrupt bit on COM1:
  mov dx, COM1_IER
  in al, dx
  or al, 0b00000001 ; Enable Received Data Available Interrupt
  out dx, al

  ; Initialize sequence number:
  mov byte [send_seq_no], 0

  ; Initialize retransmit message in send buffer:
  mov byte [send_buffer],     0x01 ; 'MARK' Start marker (Ctrl-A)
  mov byte [send_buffer + 1], 35   ; 'LEN' Packet length of 3 (+ 32)
  mov byte [send_buffer + 2], 32   ; 'SEQ' Sequence number 0 (+ 32)
  mov byte [send_buffer + 3], 'N'  ; 'TYPE' Packet type 'N' meaning NAK
  mov byte [send_buffer + 4], 0x33 ; 'CHECK' Checksum 0x13 (+ 32)
  mov byte [send_buffer + 5], 0x13 ; Terminator (Carriage Return)
  mov word [send_buffer_index], 6

  ; Get Send Initialization packet, exchange parameters...

  mov dx, message_waiting
  call print_string
  call get_valid_packet

  mov byte al, [packet_type]
  cmp al, 'S' ; 'S' = Send Initiation
  je _handle_s_packet

  ; Simplified version of error message: "<?> Packet in S State"
  mov byte [packet_data], al
  mov byte [packet_data + 1], 'S'
  mov byte [packet_type], 'E' ; 'E' = Error
  mov word [packet_data_len], 2
  call send_packet
  jmp _main_end

_handle_s_packet:
  ; Override local EOL marker from sender if available:
  mov byte al, [packet_data_len]
  cmp al, 4
  jb _acknowledge_s_packet
  mov byte bl, [packet_data + 4] ; 'EOL'
  sub bl, 32
  mov [eol_marker], bl

  ; Override local CTL marker from sender if available:
  cmp al, 5
  jb _acknowledge_s_packet
  mov byte bl, [packet_data + 5] ; 'QCTL'
  mov [ctl_marker], bl

_acknowledge_s_packet:
  mov byte [packet_type], 'Y' ; 'Y' = Acknowledgement (ACK)
  mov byte [packet_data],     72  ; 'MAXL'
  mov byte [packet_data + 1], 42  ; 'TIME'
  mov byte [packet_data + 2], 32  ; 'NPAD'
  mov byte [packet_data + 3], 64  ; 'PADC'
  mov byte [packet_data + 4], 45  ; 'EOL' = 0x0d (+ 32)
  mov byte [packet_data + 5], 35  ; 'QCTL' = '#'
  mov byte [packet_data + 6], 'N' ; 'QBIN' = 'N' = Will not do 8-bit quoting.
  mov byte [packet_data + 7], '1' ; 'CHKT' = '1' = Single character checksum.
  mov word [packet_data_len], 8
  call send_packet

_wait_for_file_header_packet:
  ; Get a File Header packet. If a B packet comes, we're all done:
  call get_valid_packet

  mov byte al, [packet_type]
  cmp al, 'B' ; 'B' = Break transmission
  je _handle_b_packet
  cmp al, 'F' ; 'F' = File Header
  je _handle_f_packet

  ; Simplified version of error message: "<?> Packet in F State"
  mov byte [packet_data], al
  mov byte [packet_data + 1], 'F'
  mov byte [packet_type], 'E' ; 'E' = Error
  mov word [packet_data_len], 2
  call send_packet
  jmp _main_end

_handle_b_packet:
  call send_acknowledgement_packet
  jmp _main_end

_handle_f_packet:
  mov dx, message_receiving
  call print_string

  ; Dollar terminate the received filename:
  mov word di, [packet_data_len]
  mov byte [packet_data + di], '$'
  mov dx, packet_data
  call print_string

  ; Zero terminate the received filename:
  mov byte [packet_data + di], 0

  ; Call DOS to create new file and handle.
  mov ah, 0x3c
  mov cx, 0 ; Standard attributes.
  ; DX already containing pointer to packet data.
  int 0x21
  jc _handle_f_packet_error
  mov [file_handle], ax

  call send_acknowledgement_packet

_wait_for_data_packet:
  ; Get Data packets. If a Z packet comes, the file is complete:
  call get_valid_packet

  mov byte al, [packet_type]
  cmp al, 'Z' ; 'Z' = End of file
  je _handle_z_packet
  cmp al, 'D' ; 'D' = Data Packet
  je _handle_d_packet

  ; Simplified version of error message: "<?> Packet in D State"
  mov byte [packet_data], al
  mov byte [packet_data + 1], 'D'
  mov byte [packet_type], 'E' ; 'E' = Error
  mov word [packet_data_len], 2
  call send_packet
  jmp _main_end

_handle_z_packet:
  ; Call DOS to close file handle.
  mov ah, 0x3e
  mov bx, [file_handle]
  int 0x21

  call send_acknowledgement_packet

  mov dx, message_ok
  call print_string

  jmp _wait_for_file_header_packet

_handle_d_packet:
  ; Call DOS to write to file.
  mov ah, 0x40
  mov word bx, [file_handle]
  mov word cx, [packet_data_len]
  mov dx, packet_data
  int 0x21
  jc _handle_d_packet_error

  call send_acknowledgement_packet

  jmp _wait_for_data_packet

_handle_f_packet_error:
  ; Send error code 'C', since new file could not be created.
  mov byte [packet_data], 'C'
  mov byte [packet_type], 'E' ; 'E' = Error
  mov word [packet_data_len], 1
  call send_packet
  jmp _main_end

_handle_d_packet_error:
  ; Send error code 'W', since new file could not be written to.
  mov byte [packet_data], 'W'
  mov byte [packet_type], 'E' ; 'E' = Error
  mov word [packet_data_len], 1
  call send_packet
  jmp _main_end

_main_end:
  mov dx, message_done
  call print_string

  ; Disable interrupt bit on COM1:
  mov dx, COM1_IER
  in al, dx
  and al, 0b11111110 ; Disable Received Data Available Interrupt
  out dx, al

  ; Exit to DOS.
  mov ah, 0x4c
  int 0x21

; PROCEDURE: get_valid_packet
;
; INPUT:
;   N/A
;
; OUTPUT:
;   ds:[packet_type]
;   ds:[packet_data]
;   ds:[packet_data_len]
;
get_valid_packet:
  push ax
  push bx
  push cx

  ; Try to get a valid packet with the desired sequence number.

  mov cx, 5 ; Retry maximum 5 times.
_get_valid_packet_loop:
  call recv_packet

  mov byte al, [recv_seq_no]
  mov byte bl, [send_seq_no]
  cmp al, bl
  jne _get_valid_packet_resend
  mov byte al, [packet_type]
  cmp al, 'Q' ; 'Q' = Block check error
  je _get_valid_packet_resend
  jmp _get_valid_packet_return ; Got a valid packet.

_get_valid_packet_resend:
  call com_port_send ; Contains a retransmit message in send buffer already.

  push dx
  mov dl, '%' ; Indicate retry.
  call print_character
  pop dx

  loop _get_valid_packet_loop ; Until CX = 0

  mov byte [packet_type], 'T' ; 'T' = Timeout

_get_valid_packet_return:
  pop cx
  pop bx
  pop ax
  ret

; PROCEDURE: send_acknowledgement_packet
;
; INPUT:
;   N/A
;
; OUTPUT:
;   N/A
;
send_acknowledgement_packet:
  mov byte [packet_type], 'Y' ; 'Y' = Acknowledgement (ACK)
  mov word [packet_data_len], 0
  call send_packet
  ret

; PROCEDURE: send_packet
;
; INPUT:
;   ds:[packet_type]
;   ds:[packet_data]
;   ds:[packet_data_len]
;   
; OUTPUT:
;   N/A
;
send_packet:
  push ax
  push bx
  push cx
  push di
  push si

  mov di, send_buffer
  mov byte [di], 0x01
  inc di

  mov word ax, [packet_data_len]
  add al, 35 ; 32 + 3 bytes for 'SEQ', 'TYPE' & 'CHECK'
  mov bl, al ; Checksum = LEN
  mov byte [di], al
  inc di

  mov byte al, [send_seq_no]
  add al, 32
  add bl, al ; Checksum += SEQ
  mov byte [di], al
  inc di

  mov byte al, [packet_type]
  add bl, al ; Checksum += TYPE
  mov byte [di], al
  inc di

  mov si, packet_data
  mov word cx, [packet_data_len]
  test cx, cx
  jz _send_packet_empty
_send_packet_loop:
  mov al, [si]
  mov [di], al
  add bl, al ; Checksum += DATA
  inc di
  inc si

  loop _send_packet_loop ; Until CX = 0
_send_packet_empty:

  ; Calculate checksum:
  mov cl, bl
  and cl, 192
  shr cl, 1 ; 8086 is limited to one shift at a time.
  shr cl, 1
  shr cl, 1
  shr cl, 1
  shr cl, 1
  shr cl, 1
  add cl, bl
  and cl, 63
  add cl, 32
  mov byte [di], cl
  inc di

  mov byte al, [eol_marker]
  mov byte [di], al

  mov word ax, [packet_data_len]
  add ax, 6 ; Add 'MARK', 'LEN', 'SEQ', 'TYPE' 'CHECK' and terminator.
  mov word [send_buffer_index], ax

  call com_port_send

  ; Increment packet sequence number:
  inc byte [send_seq_no]
  and byte [send_seq_no], 63 ; Always reduce to 6 bits.

  push dx
  mov dl, '.'; Indicate ACK sent.
  call print_character
  pop dx

  pop si
  pop di
  pop cx
  pop bx
  pop ax
  ret

; PROCEDURE: com_port_send
;
; INPUT:
;   ds:[send_buffer]
;   ds:[send_buffer_index]
;   
; OUTPUT:
;   N/A
;
com_port_send:
  push ax
  push cx
  push dx
  push si

  mov si, 0
  mov word cx, [send_buffer_index]
_com_port_send_byte:

  mov dx, COM1_THR
  mov byte al, [send_buffer + si]
  out dx, al

  mov dx, COM1_LSR
_com_port_send_wait:
  in al, dx
  and al, 0b00100000 ; Empty Transmit Holding Register
  test al, al
  jz _com_port_send_wait ; Busy wait...

  inc si
  loop _com_port_send_byte ; Until CX = 0

  pop si
  pop dx
  pop cx
  pop ax
  ret

; PROCEDURE: recv_packet
;
; INPUT:
;   N/A
;   
; OUTPUT:
;   ds:[packet_type]
;   ds:[packet_data]
;   ds:[packet_data_len]
;   ds:[recv_seq_no]
;
recv_packet:
  push ax
  push bx
  push cx
  push dx
  push di
  push si

  call com_port_recv

  ; Look for 'MARK' start marker 0x01 (Ctrl-A) in buffer:
  mov si, -1
_recv_packet_look_for_marker:
  inc si
  mov ax, [recv_buffer_index]
  cmp si, ax
  jge _recv_packet_fail ; Reached end of buffer.
  mov byte al, [recv_buffer + si]
  cmp al, 0x01 ; (Ctrl-A)
  jne _recv_packet_look_for_marker
  ; Start position now in SI register.

  ; Copy initial packet fields:
  ; * Using AL for data.
  ; * Using BL for checksum.
  ; * Using CX for packet length.
  inc si
  xor cx, cx
  mov byte cl, [recv_buffer + si] ; Packet 'LEN' field.
  mov bl, cl ; Checksum = LEN
  sub cx, 35 ; 32 + 3 bytes for 'SEQ', 'TYPE' & 'CHECK'
  inc si
  mov byte al, [recv_buffer + si] ; Packet 'SEQ' field.
  add bl, al ; Checksum += SEQ
  sub al, 32
  mov byte [recv_seq_no], al
  inc si
  mov byte al, [recv_buffer + si] ; Packet 'TYPE' field.
  add bl, al ; Checksum += TYPE
  mov byte [packet_type], al
  inc si
  ; Packet length now in CX register.
  ; Checksum now in BL register.
  ; Start of data position now in SI register.

  mov word [packet_data_len], cx
  test cx, cx
  jz _recv_packet_checksum ; Zero size packet, skip decoding/copying.

  ; Copy packet data:
  ; * Using AL for data.
  ; * Using BL for checksum.
  ; * Using CX for packet length.
  ; * Using DL for comparisons and temporary storage.
  ; * Using DH for decode flag.
  xor dh, dh
  mov di, packet_data
_recv_packet_copy:
  mov byte al, [recv_buffer + si] ; Packet 'DATA' field.
  add bl, al ; Checksum += DATA
  mov byte dl, [packet_type]
  cmp dl, 'S' ; 'S' = Send Initiation
  jne _recv_packet_decode ; Type 'S' packets shall not be decoded!
  mov [di], al ; Copy un-decoded.
  jmp _recv_packet_increment

_recv_packet_decode:
  cmp dh, 0
  jne _recv_packet_decode_flag_not_set_1
  mov byte dl, [ctl_marker]
  cmp dl, al
  jne _recv_packet_decode_flag_not_set_1
  mov dh, 1
  dec byte [packet_data_len] ; Decoding reduces resulting packet size.
  jmp _recv_packet_increment_source_only

_recv_packet_decode_flag_not_set_1:
  cmp dh, 1
  jne _recv_packet_decode_flag_not_set_2
  xor dh, dh

  mov dl, al
  and dl, 127
  cmp dl, 62
  jng _recv_packet_decode_flag_not_set_2
  cmp dl, 96
  jg _recv_packet_decode_flag_not_set_2
  xor al, 64

_recv_packet_decode_flag_not_set_2:
  mov [di], al
_recv_packet_increment:
  inc di
_recv_packet_increment_source_only:
  inc si
  loop _recv_packet_copy ; Until CX = 0

_recv_packet_checksum:
  ; Calculate and check checksum:
  mov dl, bl
  and dl, 192
  shr dl, 1 ; 8086 is limited to one shift at a time.
  shr dl, 1
  shr dl, 1
  shr dl, 1
  shr dl, 1
  shr dl, 1
  add dl, bl
  and dl, 63
  mov byte al, [recv_buffer + si] ; Packet 'CHECK' field.
  sub al, 32
  cmp al, dl
  jne _recv_packet_fail

  ; All OK!
  jmp _recv_packet_ok

_recv_packet_fail:
  mov byte [packet_type], 'Q' ; 'Q' = Block check error
_recv_packet_ok:
  pop si
  pop di
  pop dx
  pop cx
  pop bx
  pop ax
  ret

; PROCEDURE: com_port_recv
;
; INPUT:
;   N/A
;   
; OUTPUT:
;   ds:[recv_buffer]
;   ds:[recv_buffer_index]
;
com_port_recv:
  push ax
  push dx
  push di

  mov di, 0
_com_port_recv_byte:

  mov dx, COM1_IIR
_com_port_recv_wait:
  in al, dx
  and al, 0b00001110 ; Identification
  cmp al, 0b00000100 ; Enable Received Data Available Interrupt
  jne _com_port_recv_wait ; Busy wait...

  mov dx, COM1_RBR
  in al, dx

  cmp di, RECV_BUFFER_SIZE
  jb _com_port_recv_copy
  mov di, 0 ; Reset and wrap to prevent overflow.
_com_port_recv_copy:
  mov byte [recv_buffer + di], al
  inc di

  ; Keep reading until a terminator 0x0d (Carriage Return) arrives:
  cmp al, 0x0d
  jne _com_port_recv_byte

  mov word [recv_buffer_index], di

  pop di
  pop dx
  pop ax
  ret

; PROCEDURE: print_character
;
; INPUT:
;   dl
;   
; OUTPUT:
;   N/A
;
print_character:
  push ax
  push dx
  ; Call DOS to display character:
  mov ah, 0x2
  ; DL set by caller...
  int 0x21
  pop dx
  pop ax
  ret

; PROCEDURE: print_string
;
; INPUT:
;   dx
;   
; OUTPUT:
;   N/A
;
print_string:
  push ax
  ; Call DOS to display string:
  mov ah, 0x9
  ; DS is already same as CS, no need to change.
  ; DX set by caller...
  int 0x21
  pop ax
  ret

section .data:
recv_buffer_index:
  dw 0 ; 16-bit word due to SI/DI registers.
recv_buffer:
  times RECV_BUFFER_SIZE db 0

send_buffer_index:
  dw 0 ; 16-bit word due to SI/DI registers.
send_buffer:
  times SEND_BUFFER_SIZE db 0

send_seq_no:
  db 0
recv_seq_no:
  db 0

packet_type:
  db 0
packet_data_len:
  dw 0 ; 16-bit word due to SI/DI registers.
packet_data:
  times PACKET_DATA_SIZE db 0

ctl_marker:
  db '#'  ; Default
eol_marker:
  db 0x0d ; Default

file_handle:
  dw 0

message_waiting:
  db "Waiting...", 0x0d, 0x0a, "$"
message_receiving:
  db "Receiving: $"
message_ok:
  db "(OK)", 0x0d, 0x0a, "$"
message_done:
  db "(DONE)", 0x0d, 0x0a, "$"
          

set modem type none
set line /dev/ttyUSB0
set carrier-watch off
set speed 9600
set flow none
set parity none
set stop-bits 1
send <filename>