Dosemu2 Versions Save

There are over ~3300 commits since the last preview release (pre8) and a very large chunks of dosemu2 architecture were written and stabilized. Hopefully it would be possible to do more frequent releases in the future and avoid such a long development cycles.

Note: because of the new architecture in place, we suggest to re-install dosemu completely. I.e. erase your /etc/dosemu ~/.dosemurc ~/.dosemu/.dosemurc and clean ~/.dosemu/drive_c from any system/boot files (or remove ~/.dosemu completely if there is nothing important within). Compatibility mode (to run old setups) is present but may require some manual adjustments. Also note that compatibility mode means a reduced feature set. If you insist on an old setup but dosemu2 doesn't pick it up properly, don't hesitate to ask for help on our github discussions page.

Summary of user-visible changes:

• fdpp is now our default OS. It is a 64bit DOS core that boots under dosemu2 and allows to work without installing any DOS. Of course you can still install any DOS if you want, but that will in most cases only cause the features reduction.
• comcom32 is our default shell. comcom32 is a command.com variant that runs in 32bit space. Eventually we aim for the 64bit shell, but so far we only have this. You can still use your favourite shell if you want.
• Worked out the security model. We hope that dosemu2 now provides a relatively secure sandbox environment, and yet exposes all the needed features. Exposing features in a secure manner (rather than to simply declare them insecure and disable) was a challenge.
• Added KVM-assisted acceleration to DPMI (@bartoldeman).
• Added TTF support (@andrewbird)
• Implemented region locking and share support in MFS. One of the most requested/missed feature of dosemu1 times.
• Implemented $_trace_mmio option (@dos4boss)
• Lots of speed-ups to simx86 (@bartoldeman)
• Lots of i18n work.
• musl support
• Added lots of CI tests (@andrewbird)

Re-branding to dosemu2 and license change. No-turnaround point.

We have ~300 commits, many of which are bug-fixing, as pre7 was horribly buggy due to heavy development. As for the newly introduced regressions - not too much known at this time, except the drop of clang support. We hope to get clang support back again in the very near future.

Summary of changes:

• Improved hx-extender support so that the win32 version of quake2 can now work under dosemu2 (in pre7 it was supposed to but didn't).
• Support for external EMS managers like emm286.exe was (partially) implemented. As the result, we have a new UMB driver, umb.sys, that allows to enable UMB without also enabling EMS, leaving this possibility to an external driver.
• New DOSes supported: RxDOS 7.1.x and 7.2, PC-MOS 5.01.
• fossil driver got updates and missing functionality additions.
• Sound stack got updates to reduce the latencies.
• Passing DOS commands via dosemu's cmdline was changed, see man for details. Many new possibilities added, like passing environment variables and more.
• Some no longer used commands (comline.com, ecpuon.com, ecpuoff.com) were removed.
• Dumb terminal mode now handles the charsets.
• Fixes to all regression bugs of pre7 - there were many of them.

We have over 700 commits, mostly targeted on re-introducing and fixing the features previously supported in dosemu1, and a couple of new ones. Unfortunately we also have a few regressions. Summary below.

• Reworks to SDL plugin. The HW-accelerated rendering is now disabled by default, as well as the scaling filters, and full-screen switching may not work. If you want to use HW-accelerated rendering, try $_SDL_swrend = (off). If you want scaling filters or full-screen, use 'dosemu -X'. We will try to improve the SDL support in future releases.
• HX extender now fully supported, quake2 works!
• Mouse wheel support implemented
• Support booting OpenDOS and some old versions of MS-DOS.
• 2 new keyboard plugins implemented ("stdio" and "tty") to allow dumb terminal mode to work without slang library. Selectable with '-kt', '-ks'.
• VGA pass-through in text-mode console is now fully supported. Hope no one uses it though.
• Windows-3.1 support is fully re-introduced, and is actually much better than in dosemu1. We also provide the mouse driver for windows-3.1 that allows the use of the host's mouse pointer: https://github.com/stsp/win31-mouse-driver/tree/master/out
• Resurrected basic Windows-3.0 support.
• Foxpro support re-introduced.
• Fixes to SVGA/VESA modes. Support for some missing modes added.
• Many fixes to gfx remapper. The various annoying video artifacts should now be fixed.
• SB16 fixes to support sound on more games.
• Mouse copy/paste support is fully re-introduced.
• New $_bootdrive option allows to boot from any drive, not only C.
• Net: IPX and packet driver are fully functional again.
• Lots of build system improvements. We have now the debian build support and "make uninstall".
• X fonts are resurrected and provided again.
• Many fixes and improvements: DPMI support is now much more reliable, x86 JIT is more reliable, many performance improvements.
• Many updates to interrupt routing code.
• Resurrected emufs.sys.
• Sanitize syntax of lredir2: silly LINUX\FS is no longer needed.

See NEWS for more info.

We have around 500 commits since pre5 with the highlights below:

• KVM is now enabled by default on 64bit builds. A huge speed-up!
• SDL plugin now uses hardware-accelerated texture updates instead of the (slow) drawing surface
• virtual modem support is added
• serial port fifos now work again (were broken/unsupported in dosemu2 but worked in dosemu1)
• DPMI context switching is rewritten for speed-up, using a new linux kernel extensions and the code from libtask and libpcl
• default DPMI memory size enlarged to 128Mb, which is enough for all known DOS programs
• new builtin command system.com is added that runs DOS commands specified via the unix env vars. Similar functionality in unix.com is kept for compatibility.
• DOSDRIVE_D var is removed. Use new DOSDRIVE_EXTRA variable.
• mouse driver got a huge overhaul for improved robustness in non-grab mode
• winos2 mouse extension is implemented for better support of the OS/2 mouse driver under windows-3.1
• middle mouse button is now supported (was broken)
• dosdebug fixes
• many fixes to SDL plugin
• the home dir is no longer exposed to DOS by default. Use -home if you need this.
• added -cdrom option that tries to mount the cdrom and expose it to DOS
• $_hdimage option can now embed environment variables
• many performance bottlenecks were located and fixed
• many fixes and updates

See NEWS for more info.

• SDL video backend is now default, which means a GPU-accelerated rendering
• lredir command was deprecated, use lredir2 with the new syntax
• unix.com syntax was slightly changed
• new tool sound.com is added to change sound and MIDI parameters at run-time
• LPT2 is now pre-configured to print to PDF files
• Added preliminary support for old MS-DOSes (>=3.3) and some DR-DOSes
• many improvements to dosdebug
• use logarithmic volume scale for sound
• Preliminary KVM support - a very fast execution on 64bit machines. Should be manually enabled in config for now.
• Many regressions fixed
• Added valgrind support, which allowed to find many obscure bugs
• Work-arounds to support the newer fluidsynth for MIDI
• More versions of libao are supported for sound (each having its own bugs). This is good when SDL2 is unavailable.
• munt support for mt32 (you need to download Roland ROMs yourself)
• built-in backtracer is added for a better crash logs. Used if gdb is not installed.
• clang is now supported to compile dosemu2

dosemu2 starts here. This tag is only for git bisects and the like.

This is mainly a stabilization release. After a heavy development phase, we now have something that should at least boot and work for some time. :) Many many regressions were fixed.

Highlights:

• Support new gcc and gold linker
• Sound stack was enriched with ladspa plugins
• DPMI stability fixes
• Many regressions fixed

Mostly sound stuff. New sound stack is finally completed and delivered by default.

Too much to describe. :)