How do I get more Conventional DOS memory?

From OHRRPGCE-Wiki
Jump to navigationJump to search
This article only applies to the DOS/QuickBasic version. It is not relevant for the current Windows and Linux versions

If you are using the Windows or Linux versions, then Conventional DOS memory does not matter.


The first 640k of RAM in your computer is called "Conventional" memory, or DOS memory. This is the memory that the OHRRPGCE runs in. Normally, you have plenty of that conventional memory free to use, but some computers are configured so that unnecisary drivers are loaded into that memory.

The most common culprit is DOS CD-ROM drivers. A computer running Windows 9X has absolutely no need for DOS CD-ROM drivers, because the built-in windows drivers can handle your CD drive, even from DOS programs. Unfortunately, many PC manufacturers still preinstall the CD driver anyway out of superstition, and most CD-ROM manufacturers package a CD-driver on a disk without labeling it as a DOS-only driver.

This is how to disable your DOS CD-ROM drivers, and reclaim the wasted conventional memory that they consume:

Okay, the easyest way to edit CONFIG.SYS and AUTOEXEC.BAT is to go to "Run" on the START menu, and type SYSEDIT

that will bring up the system file editor, including AUTOEXEC.BAT and CONFIG.SYS

In AUTOEXEC.BAT, you can temporaraly disable lines by adding the word REM to the beginning of them. Find the line that loads MSCDEX.EXE and "REM" it out... something like this:

  REM C:\WINDOWS\MSCDEX.EXE /D:MSCD000

the REM will prevent the driver from loading. See the name after the /D? "MSCD000". Yours will have a name there too, although it might be a different name. Look for it in your CONFIG.SYS

When you find the DEVICE= line in your CONFIG.SYS that uses the same device name that MSCDEX used, add a ; to the beginning of it to disable it. (yours may not be CDROM.SYS, it depends on your CD drive)

  ;DEVICE=C:\CDROM\CDROM.SYS /D:MSCD000

The ; in CONFIG.SYS works exactly like the REM in AUTOEXEC.BAT

Now, save the changes to AUTOEXEC.BAT and CONFIG.SYS, and reboot your computer. When it starts up again, try out your CD-drive. It will still be working fine, even from DOS programs.

Now you should have enough conventional DOS memory free to run GAME.EXE (at the time of this writing, GAME-QB.EXE requires approximately 574k of conventional memory)

See also[edit]