Search found 20 matches

by jamjamason
Sep 28, 2015 17:49
Forum: DOS
Topic: Issues in real DOS on a 486
Replies: 17
Views: 5816

Re: Issues in real DOS on a 486

Sounds like you need Powerbasic for DOS.

http://powerbasic.com/products/pbdos/

I used it for twenty years on everything from 386 to Pentium 4. Blazingly fast compilation and tiny executables size.
by jamjamason
Feb 27, 2015 20:40
Forum: DOS
Topic: Strange bug in ISR
Replies: 6
Views: 2271

Re: Strange bug in ISR

Had a similar problem where the SLEEP command was unloading my interrupt handler from the interrupt vector table. I didn't find a solution to it, nor an explanation for why it happened. I just had to stop using SLEEP.

If you find out anything, let me know!
by jamjamason
Nov 13, 2014 18:05
Forum: DOS
Topic: Interrupt Vector Table changes on INKEY or SLEEP
Replies: 0
Views: 1427

Interrupt Vector Table changes on INKEY or SLEEP

I've written a com port interrupt handler, and it loads and works as expected UNTIL my program uses either INKEY or SLEEP (there may be others; those are the only two I've found). If I examine the interrupt vector address after either of those two statements using _go32_dpmi_get_protected_mode_inter...
by jamjamason
Oct 20, 2014 17:25
Forum: DOS
Topic: New DOS Ver 1.00.0
Replies: 14
Views: 5901

Re: New DOS Ver 1.00.0

It looks like the download links in the News forum post and on the Downloads page still point to version 1.00.0, which means I just downloaded the non-working version, installed it and spent some time fixing up my directory structure and copying source, etc., only to find this bug, search for it on ...
by jamjamason
Oct 14, 2014 16:23
Forum: DOS
Topic: LFN vs FreeBasic program -> CRASH
Replies: 2
Views: 1309

Re: LFN vs FreeBasic program -> CRASH

Have you tried a version of DOS that natively supports LFN? I use the version of DOS that came with Windows 98 and don't have any problems.

This test would at least tell you whether the problem is with DOSLFN.EXE, or your FreeBasic program...
by jamjamason
Apr 25, 2014 15:57
Forum: DOS
Topic: Capture IP network frame
Replies: 6
Views: 2436

Re: Capture IP network frame

My apologies; I thought I had posted these weeks ago, and come back from a business trip to see I'd left you waiting. Face palms all around... https://osu.box.com/s/8dvkaeps4d6ifelpxmed https://osu.box.com/s/r9vj0l33xs80hz0zlgbi https://osu.box.com/s/2juuomlj2ubqxexlu52y
by jamjamason
Mar 31, 2014 18:19
Forum: DOS
Topic: Capture IP network frame
Replies: 6
Views: 2436

Re: Capture IP network frame

It's possible, but not easy. You'll need to write your own assembly code to capture the data passed to you by the network stack interrupts. I dabbled with this last year, but gave up after a few weeks when I realized how much effort it was going to take to get anything useful running. You're welcome...
by jamjamason
Jan 28, 2014 2:02
Forum: DOS
Topic: DPMI in Virtual Machine reports wrong physical memory size?
Replies: 6
Views: 2347

Re: DPMI in Virtual Machine reports wrong physical memory si

Problem solved! The KVM/QEMU virtual machine that comes with Centos 6.4 uses an old version of SEABios (v 0.6). I upgraded it to the latest version (v 1.7) and I'm now getting the correct information from INT15h for the physical memory, and no more swapping by either DPMI.
by jamjamason
Jan 23, 2014 20:19
Forum: DOS
Topic: DPMI in Virtual Machine reports wrong physical memory size?
Replies: 6
Views: 2347

Re: DPMI in Virtual Machine reports wrong physical memory si

When I probe the VM memory without DPMI, I get 382MB. No errors of any kind. I have a protected mode assembly routine that tests all memory locations by setting a flat memory model (not using DPMI), and it has no problems reading and writing all 382MB, and it doesn't change speed as it does so. Usin...
by jamjamason
Jan 22, 2014 20:23
Forum: DOS
Topic: DPMI in Virtual Machine reports wrong physical memory size?
Replies: 6
Views: 2347

Re: DPMI in Virtual Machine reports wrong physical memory si

Thanks for that, MichaelW. The results from your code agree with the results from the DPMI.EXE test program that comes with HDPMI: Booting into MSDOS natively, the total physical memory returned by INT15h is correct, whether using CWSDPMI or HDPMI. Booting MSDOS inside a QEMU virtual machine, the to...
by jamjamason
Jan 17, 2014 21:15
Forum: DOS
Topic: DPMI in Virtual Machine reports wrong physical memory size?
Replies: 6
Views: 2347

DPMI in Virtual Machine reports wrong physical memory size?

I need a 200MB image buffer for a data acquisition program running in a KVM-QEMU virtual machine under Centos. However, both CWSDPMI and HDPMI report only 64MB physical memory available. Is this a known problem, or can any DPMI gurus here point me to my next step to resolve this? Thanks in advance, ...
by jamjamason
Oct 03, 2012 16:02
Forum: DOS
Topic: GPFs again: I'm stumped!
Replies: 6
Views: 1444

Re: GPFs again: I'm stumped!

I think it's worth noting here that the methods given by dkl and frisian work in the MAIN section of code, but when referencing variables that were passed on the stack inside a subroutine, the correct form to use is:

MOV EBX, DWord Ptr [ErrorCode]
MOV Word Ptr [EBX], AX
by jamjamason
Oct 02, 2012 17:12
Forum: DOS
Topic: GPFs again: I'm stumped!
Replies: 6
Views: 1444

Re: GPFs again: I'm stumped!

Thanks to dkl and frisian for those insights. That's very helpful!
by jamjamason
Sep 27, 2012 18:13
Forum: DOS
Topic: GPFs again: I'm stumped!
Replies: 6
Views: 1444

GPFs again: I'm stumped!

Can any kind soul enlighten me as to why the following do-nothing code causes a GPF? Thanks in advance. #LANG "fblite" DIM SHARED DMADescriptor AS USHORT DIM SHARED DMALinearAddress AS UINTEGER DIM SHARED ErrorCode AS USHORT PRINT "Starting..." ASM PUSHAD MOV EBX, DWord Ptr [Erro...
by jamjamason
Sep 27, 2012 18:08
Forum: DOS
Topic: Long filenames?
Replies: 9
Views: 2094

Re: Long filenames?

Any special reason not to use FreeDOS?


Yes; while FreeDOS appears to be stable on my older PATA drive systems, it produces frequent lockups on file access attempts on my newer SATA hardware.

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