DOS

Get More Free Memory to Run DOS Programs

One of the strongest features of the HP 100/200LX is the fact that these computers are DOS machines and will run any DOS program that does not require a processor higher than an 80186 and doesn't require a co-processor or a VGA monitor.

This leaves a vast amount of old and new DOS programs available to users of the 100/200LX. Some of these DOS programs, such as WordPerfect 5.1 for DOS or NetTamer, require quite a bit of memory to run, and until now, users were left with the following three ways to free up more memory:

  1. 1. In Setup, allocate more memory for the system and less for disk space.

  2. 2. Allocate all available memory for the running of a DOS program. Do this by appending the "pipe signal" ( | ) to the path name in the Path field of the "Add an Application Screen," which is found in Application Manager. (The pipe signal is created by pressing (Shift)+(\).)

  3. 3. Terminate all applications from the AppManager. Terminating all applications had the disadvantage that you lost the use of built-in applications like the Phone Book and Appointment Book.

Now, MeW has written a TSR (Terminate and Stay Resident) program called MaxDOS = that allows you to run virtually any size DOS program without having to leave System Manager. MaxDOS allows you to do this by using a swap file that takes an image of everything that is currently running and saving it to a temporary file, freeing up all of the DOS memory to run another program.

MaxDOS first tries to use EMS memory, if you have EMM200 = loaded. If you don't, MaxDOS saves the image to a directory specified in the AUTOEXEC.BAT file. If you are not using EMM200, a temporary directory must be designated. MaxDOS requires 600 Kb free on the drive designated.

INSTALLING MAXDOS

Copy MAXDOS.COM to a subdirectory that is included in the path statement of the AUTOEXEC.BAT file. For this example we will assume that it is in the A:\BIN directory. Then open your AUTOEXEC.BAT file in Memo and add the following lines to it:

maxdos -l 100 (or 200) maxdos -r

The first line loads MaxDOS, the second line starts the System Manager and the last line unloads MaxDOS. If there are other TSRs loaded in the AUTOEXEC.BAT file, MaxDOS should be loaded before them and removed after them.

To use MaxDOS with your DOS programs, set the DOS program to start from Application Manager, using the following Path statement in the setup screen. (For this example, we'll set up WordPerfect.)

Path: a:\bin\maxdos.com a:\wp\wp.exe| This will start WordPerfect on your Palmtop using the maximum amount of memory available without having to terminate the System Manager.

Tom Gibson

tom_gibson@thaddeus.com