So what's possible to do with this computer ?

[Elia1995]

Hi folks, as most of you might know, this Summer I got a bunch of retro hardware, including several computers.
One of these computers is an AST BRAVO 486/25 with 4MB "proprietary" SIMM RAM, no other SIMMs fit those slots, so currently I cannot upgrade it at all.
I "borrowed" the hardisk from my Olivetti M4 434S (since it's currently off limits, due to graphical problems), installed it in that computer and got my DR. DOS 7.03 working, most games do work, some perfectly, others laggy.
I tried a lot of Apogee games, ID software (Commander Keen) and I even tried to run some Epic Megagames games.
Duke Nukem 2, Monster Bash, Ken's Labyrinth, Jazz Jackrabbit, One Must Fall 2097, Doom, Doom 2 and other games don't start at all, not for the 486 DX2 (which probably is the only decent thing in that PC), but for low memory.
Duke Nukem 2 require at least 2 and something MB, while I have roughly 687 kb free with the OS "just booted" and with EVERYTHING I need (Sound Blaster drivers and CD-ROM drive) loaded in high memory (LH).

So... what exactly is this computer for ? What's the maximum I can get out of 4MB of RAM, which don't even reach 4MB at all on DR. DOS 7.03 ?
Ah yes, I also have Windows 3.11 installed and it works

[cyclone3d]

To access the RAM above the 1MB low memory, you need to use HIMEM and/or EMM386 depending on what the program wants.

You are most definitely not using anything above the low 1MB memory by just loading DOS.

[Elia1995]

How do i only have 687KB of free conventional memory at boot then?

[andreja6]

Did you enable HIMEM or EMM386 in the AUTOEXEC.BAT?

[derSammler]

How do i only have 687KB of free conventional memory at boot then?

Exactly because of that. Without HIMEM, no memory above 1 MB is visible to DOS. HIMEM gives you XMS; EMM386 will convert XMS to EMS, in case a game needs this instead of XMS.

ps: in DR DOS, names of the memory managers may differ. No idea, never used that...

[Elia1995]

I have this in the config.SYS:

Code: Select all

DEVICE=C:\Windows\HIMEM.SYS
DOS=HIGH,UMB
DEVICE=C:\Windows\EMM386.EXE NOEMS

But I see that's for Windows, so what's for Dr. DOS?

[derSammler]

Output of mem /c ?

[Elia1995]

What?

[Jo22]

What?

He means it would be helpful to see what the command MEM /C displays to screen.
If text goes away too fast, just add a /P parameter (/P for pause).
You can also enter MEM /C >mem.txt and get a text file.

[Elia1995]

Ah, ok, here's a photo of MEM



Here are the contents of my autoexec (autodos7.bat) and config (dconfig.sys) files:

AUTODOS7.BAT

Code: Select all

@ECHO OFF
SET SOUND=C:\SB16
SET BLASTER=A220 I5 D1 H5 P330 T6
SET MIDI=SYNTH:1 MAP:E
C:\SB16\DIAGNOSE /S /W=C:\WINDOWS
C:\SB16\MIXERSET /P /Q
REM LH /L:0;1,44048 /S C:\WINDOWS\SMARTDRV.EXE
ECHO SmartDRV Disabled to save some memory ;)
PATH C:\DRDOS;C:\NWCLIENT;C:\WINDOWS;%PATH%;C:\
PROMPT TIME Elia1995 $P$G
SET DIRCMD=/4
MODE CON: CP PREP=((850) C:\DRDOS\EGA.CPI)
MODE CON CP PREPARE=((850)C:\DOS71\EGA.CPI)
MODE CON CP SELECT=850
KEYB IT+
REM LH /L:1,2912 KILLER
DOSKEY
LH /L:1,15408 DOSLFN /Z:C:\DOS71\CP850UNI.TBL
REM Remove the "REM" on the below command when testing the Celeron rig to get CD working
REM LH MSCDEX /D:IDE-CD
SHARE /L:30
REM LH NLSFUNC
REM LH SMARTDRV
REM LH /L:0;1,3328 /S CTMOUSE
REM For compatibility purpose:
REM CTMOUSE > NUL
ECHO.
LH C:\DRDOS\DRMOUSE.COM
REM For locking volumes to enable "direct disk access":
LOCK /T:1
BREAK ON
LFNFOR ON
ECHO Now you are in Dr. DOS 7.03 prompt. Type 'HELP' for help.
ECHO.
EMM386 PIC=ON
DPMI OFF
VERIFY OFF
SET DRDOSCFG=C:\DRDOS
NLSFUNC C:\DRDOS\COUNTRY.SYS
CHCP 437
NWCACHE 7670 1024 /LEND=ON /DELAY=OFF
REM Enable the below CALL to get working CD with the parallel port when using the 486 rig:
CALL C:\CDCONNEC.BAT
CD\
REM CALL C:\GIOCHI\MENU.BAT
REM C:\WINDOWS NET START
REM C:\WINDOWS\LSL.COM
REM C:\WINDOWS\ODIHLP.EXE


DCONFIG.SYS:

Code: Select all

DEVICE=C:\DOS71\HIMEM.SYS
REM DEVICE=C:\DRDOS\EMM386.EXE DPMI=OFF FRAME=NONE RAM
DEVICE=C:\DRDOS\EMM386.EXE RAM
DEVICE=C:\DRDOS\DPMS.EXE
DOS=HIGH,UMB
BUFFERS=80
FILES=40
LASTDRIVE=Z
FCBS=4,4
DEVICEHIGH=C:\CTCM\CTCM.EXE
REM DEVICE=C:\DOS71\ECHO.SYS W/E/L/C/O/M/E /T/O  MS-DOS 7.10...
REM DEVICE=C:\DOS71\ECHO.SYS C/O/P/Y/R/I/G/H/T M/I/C/R/O/S/O/F/T C/O/R/P. A/L/
DEVICEHIGH=C:\DOS71\ECHO.SYS E/L/I/A/1/9/9/5 /S/ /E/P/I/C /4/8/6 /R/I/G
DEVICEHIGH=C:\DOS71\ECHO.SYS /(/C/)/E/L/I/A/1/9/9/5 /2/0/1/6
DEVICE=C:\DRDOS\SETVER.EXE
REM DEVICEHIGH=C:\DOS71\POWER.EXE
REM DEVICE=C:\DOS71\VIDE-CPP.SYS /D:IDE-CD
DEVICEHIGH=C:\DRDOS\DISPLAY.SYS CON=(EGA,,1)
COUNTRY=44,,C:\DRDOS\COUNTRY.SYS
SHELL=C:\DRDOS\COMMAND.COM C:\DRDOS\ /E:640 /P:AUTODOS7.BAT
BREAK=OFF
HISTORY=ON,512,ON
REM ** FILES=30
STACKS=9,256
SET PATH:C\DRDOS;C:\WINDOWS;.


I have no idea what most of the lines mean, for example the "HISTORY=ON,512,ON" in the config or the "/L:*numbers*" part before loading certain things, like KILLER or CTMOUSE (which are all "REM"med, so they don't load at all anyway).
I do have it dual boot with MS-DOS 7.10, both systems work perfectly and both give me the exact same memory issues, although when I had this hardisk in the Olivetti, every game I had here worked perfectly and used all the 16MB of RAM it had !!! So why now it doesn't read these 4 megabytes ? They're all detected correctly in the computer startup, and in "mem" aswell, I only have 627K of free DOS memory, though for some reason...

[brostenen]

Looks like you got all memory loaded by the system. Just to be shure....

You do know that largest executeable program is not the same as the total memory?
And you do know, that Dos has this 640k barrier, and the rest are just extended and expanded memory?

Looking at your screenshot, you have a computer that pretty much see all the memory in it.

[Elia1995]

Would a fresh 6.22 with just the Sound Blaster and LTP CD-ROM drivers help?

[derSammler]

Looks like you got all memory loaded by the system.

Doesn't look correct to me. 1.4 MB XMS memory are missing. There are 3.4 MB of XMS from which ~2 MB are converted to EMS. But the rest is not listed as available.

I'd recommend removing EMM386 from config.sys, as most games from 199x are using XMS anyway. It's important to understand that XMS and EMS are not interchangeable. If a game needs 2 MB XMS then it's completely irrelevant how much EMS memory is available. (and vice-versa)

[Elia1995]

When Monster Bash starts, it gives me an error when I enable the sounds, because it needs 200k of EMS memory.
Jazz Jackrabbit requires 2,7 MB of free memory and it doesn't start at all.

I'm now gonna format the whole hardisk (not that I have anything to lose anyway...) and install a fresh MS-DOS 6.22, with the Sound Blaster, the LPT CD-ROM drivers and Windows 3.11.

[DeafPK]

Pardon my curiosity - but specifically which computer is this? You did mention AST with a 25 MHz 486sx.

My first PC was the Bravo LP 4/25s and even though the machine was crappy as hell I would love to see one again... nostalgia hits harder with age, apparently.

[Elia1995]

It's an AST BRAVO 486/25

This is the only photo I have it for now, I'll take a good picture of it later:

[brostenen]

Looks like you got all memory loaded by the system.

Doesn't look correct to me. 1.4 MB XMS memory are missing. There are 3.4 MB of XMS from which ~2 MB are converted to EMS. But the rest is not listed as available.

I'd recommend removing EMM386 from config.sys, as most games from 199x are using XMS anyway. It's important to understand that XMS and EMS are not interchangeable. If a game needs 2 MB XMS then it's completely irrelevant how much EMS memory is available. (and vice-versa)

Well... That is true... He only mentioned that he had a little over 640k avaliable.
I only read the 3.xxx portion and as stupid as I am, I just asumed.
Well... Need to do better in the future, stupid me.
So I read that he thought that he could not get past some 640kb to 700kb Ram loaded.

Anyway...
I think he will have better luck, sticking to MS-Dos-6.22. I think there are software issues on his installation.
Or some of the chips on one of his modules, might be bad. I truly think the motherboard it self are perfectly fine.
Yet, as I only have used Microsoft Dos and neighter DR nor IBM Dos, then I can not give any advice on his setup files.

[brostenen]

It's an AST BRAVO 486/25

This is the only photo I have it for now, I'll take a good picture of it later:

Looking at that picture, you might want to clean the sim modules and slots as well.
Looks a bit dirty on that photo, and a cleanup might do the trick in combination with MS Dos 6.22.

[Elia1995]

Yes I long cleaned the whole motherboard since I got it back in July.

[FFXIhealer]

Those look like standard 72-pinn SIMMs to me. Are we sure he can only use 4MB? He might be able to bump up to 8MB or even 16MB. And yes, those contacts look corroded/dirty as all hell. Get some DeoxIt contact cleaner and a good cloth or even a paper towel and clean that stuff. You can spray DeoxIt right on the contact sockets after you remove the RAM. An old toothbrush will clean all the contacts. Let it dry and then reinstall the (cleaned) RAM.