Cross-platform DOS emulation package
Complete, accurate emulation and more

DOSBox-X 2023.10.06 Release Notes

Release Date: October 6, 2023

Please report any issues in our issue tracker.

Also, make sure to check out our Wiki guide.

New in This Version

  • Add “VRD” debugger command to force redraw of the VGA screen.
  • Add VGA debug set commands to force a video start address and another to clear all debug settings.
  • Add “PITSYNC” option to VFRCRATE command. “VFRCRATE PITSYNC ON” directs the system timer interrupt to synchronize tick rate with vertical refresh rate of VGA emulation if the game or demo set the timer tick rate to a value close enough to vertical refresh. This is intended for games or demos that use the system timer for a vsync interrupt.
  • IMGMAKE: Fix bug where if -bat was specified, the generated .bat file would attempt to mount the .bat file, not the disk image.
  • IMGMAKE: If -nofs and -bat was specified, the generated .bat file will refer to “IMGMAKE 2” instead of “IMGMAKE C”
  • DOS FAT driver: When the guest sends in a new BIOS Parameter Block, recalculate the disk locations and FAT type properly instead of assuming that FORMAT.COM is using the same format already present.
  • DOS FAT driver: If the partition is unformatted and looks as if freshly written by FDISK, then instead of failing to mount, mount the partition instead as an unformatted partition and fail file I/O until a BPB is set and the partition formatted by FORMAT.COM. This matches MS-DOS behavior and it makes it possible to mount an image, FDISK it, restart, FORMAT.COM the unformatted partition, and end up with a working drive letter (just like MS-DOS). So far verified against MS-DOS 6.22 and Windows 98 versions of FDISK, FORMAT, SYS, and SCANDISK.
  • DOS FAT driver: Add options -o sectoff and -o sectlen to make it possible to manually specify the start and length of a partition. Future code will use this internally as well.
  • IMGMOUNT: Allow *: as a drive letter to mean automatically pick a drive letter.
  • Fix debugger to use toupper(), but only for ASCII range ncurses keycodes.
  • Timer PIT: If the guest writes the counter value while the counter gate is off, make sure the counter read back is the same value written regardless of gate status. Prior code returned the stale latched value of the counter as it was prior to shutting off the gate and writing the counter, causing timing issues.
  • Fix restoring minimized window on TTF output (Issue #4248) (maron2000)
  • Fix macos crash on launch when output=surface or auto (SDL2) (maron2000)
  • Update in-tree SDL2 library to ver 2.28.2 (maron2000)
  • Updated build tool for MinGW lowend builds required for the updated SDL2 library. As a result, MinGW lowend builds are now able to enable debugger features. (maron2000)
  • Debugger RUN and RUNWATCH commands were broken, fix. Make sure debugger shortcut triggers execution to stop whether in RUN or RUNWATCH mode.
  • Fix SETCOLORS command didn’t change color when output=ttf.(Issue #4503) Also fixed the values reported were wrong. (maron2000)
  • BIOS CMOS date/time functions will now idle the CPU 4 times after reading or setting the clock to allow interrupts, CPU time, and RTC clock ticks to proceed normally. This fixes “Pizza Tycoon” and allows it to continue past the initial logo. (joncampbell123)
  • Fix segfault when mounting hard disk images with no file extension (joncampbell123).
Previous release: 2023.09.01 (release notes)