The Explorer: Save Your Butt With DOS: Part Three - InformationWeek

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Software // Enterprise Applications
03:39 PM
Fred Langa
Fred Langa

The Explorer: Save Your Butt With DOS: Part Three

Here's a boatload of great files to finish stocking your DOS toolkit!

  • XMSDSK.EXE is a free RAM disk written by Franck Uberto in France. A RAM disk is a pseudo-hard drive (with its own drive letter) that lives entirely in your RAM chips, and remains active for as long as your system is powered on. Because there are no mechanical parts, a RAM disk is super-fast and can be useful for carrying out disk-intensive operations that normally would leave a hard drive churning: On a RAM disk, even the most disk-intensive operations fly.
  • UMBPCI is an improvement over Microsoft's "EMM386:" Due to memory architecture limitations that date back 15 years, some "upper memory blocks" (UMBs) in the address range between the top of a PC's standard memory (640K) and the start of extended memory (1MB) normally goes to waste. With the right software, these UMBs can be recovered and put to use. The usual way to do this is to include two lines in your Config.Sys:


    The first line loads EMM386, which is a driver for a very old technology called "Expanded Memory." Few apps use Expanded Memory any more; almost all (including Windows) use "Extended Memory." Because almost nothing uses Expanded memory, you add the command "NOEMS" to tell the Expanded Memory Manager that you don't really want any Expanded Memory Services.

    That sounds dumb: loading an EMS driver and then immediately turning off its EMS functions. But the EMM386 driver also gives your system access to the UMB area, and the "DOS = HIGH,UMB" line then starts to put this otherwise wasted memory to use. Thus, by loading EMM386 and turning off the Expanded memory functions via NOEMS, you gain access to UMBs that otherwise would go to waste.

    Still, that's clumsy. UMBPCI is a faster, more direct and better way to access UMBs without the rigamarole of adding and then immediately disabling an obsolete Expanded Memory Manager. It's a power tool aimed at knowledgeable users, and you'll find full info at

  • 3 Free DOS Utilities: FINDIT (a file finder), DEL-it (search for and delete file) and ACCR (ASCII Control Code Remover) are freeware programs by Steven F. Daniel. (requires free registration to download)
  • Apicd214.exe is a self-extracting Zip file containing a generic CD-ROM driver (and instructions) that will work on many systems. If you can't find Microsoft's generic drivers (Oakcdrom.sys or Nec_ide.sys) try adding this driver to your Config.Sys.
  • SHSUCDX is a free DOS-level replacement for MSCDEX, the Microsoft CD-ROM extensions for DOS. Both give you access to your CD from DOS, but unlike MSCDEX, SHSUCDX is part of a comprehensive package of DOS-level CD ROM tools that let you cache, emulate, redirect and share one or more CDs among anything from one to 48 simultaneous users.

Related resources:

By the Bootstraps

A Bevy Of Boot Disks

But Wait, There's More!
Reader Dev Teelucksingh has pulled together a page that lists many of the above DOS tools, plus lots more. And there are many sites offering a world us DOS software including:

With the resources above, plus those listed in Parts One and Two of this series, you can create an absolutely awesome DOS toolkit! Now please click on over to the discussion area and share your best DOS toolkit files, tips, tricks, and tweaks; or ask your DOS questions. See you there!

To discuss this column with other readers, please visit Fred Langa's forum on the Listening Post.

To find out more about Fred Langa, please visit his page on the Listening Post.

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