DOSBox-X is an open-source DOS emulator for running DOS games and applications.
DOSBox-X emulates a PC necessary for running many DOS games and applications that simply cannot be run on modern PCs and operating systems, similar to DOSBox.
However, while the main focus of DOSBox is for running DOS games, DOSBox-X goes much further than this.
Started as a fork of the DOSBox project, it retains compatibility with the wide base of DOS games and DOS gaming DOSBox was designed for.
But it is also a platform for running DOS applications, including emulating the environments to run Windows 3.x, 9x and ME and software written for those versions of Windows.
By adding official support for Windows 95, 98, ME emulation and acceleration, we hope that those old Windows games and applications could be enjoyed or used once more.
Moreover, DOSBox-X adds support for DOS/V and NEC PC-98 emulations so that you can play DOS/V and PC-98 games with it.
Add dosbox.conf option to control the duration of the beep when
DOS CON and INT 10h are given the BEL character. (joncampbell123).
DOS CON device BEL (beep) handling: For IBM PC modes, call on
INT 10h to make the beep, rather than duplicate code. Fix the
DOS CON device so that it can also properly beep in PC-98 mode.
(joncampbell123).
Fix bug where the "zero memory on DOS allocation" option was
stuck on. Some games, like "Bad Cat" rely on memory contents
peristing across DOS EXEC and memory allocation. (joncampbell123).
Fix Hercules palette selection related to herc blend. (joncampbell123).
DOS kernel: When executing an EXE file, the loader can now detect
EXE files that were compressed using EXEPACK. Based on the new
exepack dosbox.conf setting, it can decompress the EXE by itself,
switch off the A20 gate, or do nothing. The purpose of this
setting is to avoid EXEPACK "Packed File is Corrupt" errors that
happen if the A20 gate is enabled and the EXE was loaded too low
in memory. (joncampbell123).
Linux SDL1: Use XDG_SESSION_TYPE environment variable to detect
whether or not the user is running DOSBox-X under X11 or Wayland,
and if so, prevent the fbcon and svga drivers from initializing.
There seems to be a problem where, if run under Wayland and the
XWayland compatibility layer if not present, SDL1 uses the fbcon
driver to take over the screen using vtcon switching and the classic
fbdev driver interface. Don't do that! (joncampbell123).
INT 21h AH=4Ah resize memory: If memory resize fails because there
is not enough room for the requested amount of memory, do not
set ownership of the block to the program. This fixes memory
allocation error in California Games II. The game at one point
seems to miscalculate and ask for an excessively large amount
of memory on resize, and then fail, which doesn't seem to affect
the game. HOWEVER, prior to the bugfix, the memory block that
was available was assigned ownership to the game anyway. Later
on after helicopter takeoff, the game would attempt to allocate
more memory, which would fail because of the erroneous assignment
of ownership to free memory. (joncampbell123).
Add debug logging to not only indicate DOS kernel memory alloc,
free, and resize, but also log when the memory operation fails.
Perhaps someday I'll figure out what the memory management in
California Games II is doing wrong that makes the helicopter part
fail in DOSBox-X. (joncampbell123).
Code development now occurs across two primary branches: master
for fully functional emulation, and main-osfree for versions of
DOSBox-X where built-in MS-DOS OS emulation is disabled. The osfree
branch can only boot a guest OS. main-osfree is for use in jurisdictions
that enforce or wish to enforce OS level age verification, and
therefore, may consider the MS-DOS emulation an OS that is subject
to those laws. (joncampbell123).
El Torito CD-ROM floppy disk boot emulation is no longer as slow
as an actual floppy drive. Your bootable CDs will boot much faster
now. (joncampbell123).
DOSBox-X shell: If a DOS error happened while trying to execute a
DOS program, read the error code and print an appropriate message
on the console. So far only "Access Denied" has any specific error
message there. (joncampbell123).
Skip all keyboard code page and layout loading if running in PC-98
mode. PC-98 systems store the entire font in ROM with only very
limited room for custom fonts, therefore, it makes no sense to load
code pages in PC-98 mode. (joncampbell123).
Keyboard code page layout: Fix bug where an out of range start_pos
can cause DOSBox-X to segfault. Range check and print an error
message instead. (joncampbell123).
Keyboard code page layout: The UPX unpacker checks the stack pointer
(like a COM program would) to determine if there is enough memory
to decompress. If there is not, it executes INT 20h to exit to DOS.
Problem is, the code page execution never makes a proper PSP segment
for that to work, so, during execution, intercept INT 20h and safely
redirect execution to exit properly when called. Set an error flag
so the code can know if that happened and say so. (joncampbell123).
Keyboard code page layout: If executing the CPI/CPX file because UPX
decompression is detected, allocate memory based on the size of the
file plus reasonable stack space rather than assume about 128KB of
RAM following a DOS allocation of less, which for lower memsizes,
only causes a crash on startup. (joncampbell123).
Debug print to log what code page file is being loaded at startup (joncampbell123).
CPU Idle callback is now strictly limited to processing IRQs and one
CPU instruction, instead of however many CPU instructions can run
until the next scheduled emulator event. This fixes a bug where
system calls that use the Idle callback (INT 21h, etc) can sometimes
vary their delay time by emulator events, and if "scanline render on
demand is enabled", can cause the Idle call to take a full 1ms interval
of time. This fixes an issue where "scanline render on demand" caused
some DOS games like Xargon to take 5 to 10 times longer to transition
between title, main menu, gameplay, etc. (joncampbell123).
Debugger LOGL command now includes the PIC_FullIndex() emulator time
in millseconds so that it can be used to determine time as well as
CPU state for debugging (joncampbell123).
Add dosbox.conf option to control whether VBE emulation provides the
protected mode interface or not (joncampbell123).
Add dosbox.conf option vbememsize and vbememsizekb to control how much
video memory is reported through the VESA BIOS, which can be less than
actual video memory (but must be at least 256KB). This option can help
with some DOS programs that have problems with "too much" video memory
in the system (joncampbell123).
Add INT 10h mode flag _REQUIRE_LFB. When set, INT 10h calls to set
VESA BIOS modes will fail unless requesting to set the linear framebuffer
version of the mode (joncampbell123).
S3 emulation will mark any more large enough to exceed bank switching
limits in S3 hardware as _REQUIRE_LFB (joncampbell123).
I'm not sure why Adlib emulation defaults to 48KHz in most versions of
DOSBox, but the hardware rate is 49716 and that should be the default
(joncampbell123).
Fixed crash on starting debugger on MinGW builds (maron2000)
Adjusted the ChinaSea/Big5-2003 extended code point ranges for CP951 to
0x9140–0xA3FE and 0xC6A1–0xFEFE (1abcd)
Replaced deprecated symbols to enable launching on old macOSs (maron2000)
Converted all bash-dependent shell files to POSIX-shell compliant
(pandasoli)
Removed 7 duplicate Chinese character mappings from CP951 (Big5-UAO) (1abcd)
Added SoundBlaster microphone input support (Windows WASAPI)
(meldro364-glitch)
Fixed segfault on launch of macOS builds (maron2000)
Added OS/2 support for tinyfiledialogs, browser and external programs and
some more fixes. (josch1710)
