DOS and/or WIN-OS/2 Sessions Problems on ArcaOS

Arca Noae has comment on their website that this is a common issue running ArcaOS (OS/2) on modern hardware. . It says "Generally, this is due to an incompatibility in the BIOS of the system with the DOS VDM code in ArcaOS (inherited from IBM’s OS/2 Warp 4)."

DOS window mode shows wrongly
This is a problem found on a Thinkpad L420. DOS and Win-OS2 works fine in fullscreen, Win-OS2 also works fine on window mode, but DOS on window mode shows wrong/group/superimposed characters on the command line.

Like this image:



Commands on the DOS will work, like for example "exit" will close the window, but the characters just don't look right.

It was suggested to use: DEVICE=X:\OS2\MDOS\VSVGA.SYS /int10textgrfxsafe But on this case /int10textgrfxsafe does not solve the problem.


 * Workarround
 * Arca Noae offers this workaround "Another option, when full screen sessions work but windowed ones do not, is to open a full screen session first, and then press Alt-Home to switch it to a windowed session (this only works for DOS sessions, not OS/2 full screen and windowed sessions)."


 * That is a good trick that worked on the Thinkpad L420.


 * Patch
 * There is an experimental patch on which Arca Noae had been working - vio-1.0.wpi. You can find it on Arca Noae Ticket system. Ticket 1193

Problem: DOS Session quits after pressing any key
After starting a full-screen DOS session, a screen with "C:\" appears. After pressing any key, the screen closes and the popuplog.os2 is formed.

19.11.2020 22:58:30  SYS   0  PID 0038  TID 0001  Slot 00A7 C:\OS2\PMSHELL.EXE 16D7FFFF EEF3FFFF P1=FB92E113 P2=2F0CE14B  P3=FF62F000  P4=FEE2E10E EAX=00006247 EBX=0000FFFF  ECX=0000E118  EDX=0000FEC2 ESI=000091C3 EDI=00001240 DS=0348 DSACC=1092  DSLIM=00010FFF ES=FFFF ESACC=0000  ESLIM=00000000 FS=0000 FSACC=0000  FSLIM=00000000 GS=0000 GSACC=0000  GSLIM=00000000 CS:EIP=EB00:00000313 CSACC=0000  CSLIM=00000000 SS:ESP=FFFF:00000A74 SSACC=0000  SSLIM=00000000 EBP=00000A6A FLG=000A6212

Reported on a Motherboard Asrock B85. BIOS UEFI and compatible.

Solution
Disable DOS=UMB

Set in config.SYS DOS=HIGH,NOUMB

Links

 * Forum: Problem: DOS Session quits after pressing any key
 * Arca Noae FAQ
 * DOS-WIN-OS/2 ArcaNoae Ticket System. 1189, 1193