Mike's PCjr Page

Eleven years ago I spent $10 at a used bookstore here in Tucson for "IMSI TurboCAD Designer" 2D and 3D software on 3 1/2" 720KB diskettes, box, manual, and all. It sat on my shelf collecting dust all those years. I always thought it would be cool having CAD software that runs on the jr. So finally on Friday I tried to make the software work. The 3D software will not work on the PCjr, as 640K of free memory is needed. However, the 2D TurboCAD Designer software does work, as it needs only 512K of free memory, something jr can easily do. I thought that since I have the PC Enterprises DisplayMaster VGA sidecar with the Cirrus Logic 256KB video card, that I would be able to easily run it in color, but I never got past the color logo screen of the IMSI software. The PCE DisplayMaster allows you to switch from VGA to EGA to CGA to MGA video modes via software on the fly. Only CGA would work, either in black and white or in Hercules yellow monochrome mode. But it really works! Now I have to learn how to use the software. I did some test line and circle drawings, and it worked quite well. There is not a version on the software, but the diskettes are copyright 1991. When the software boots, it comes up Version 1.90a.

IMSI still makes TurboCAD to this day, and are now on Version 19. How is it possible that DOS CAD software can work on the PCjr? Interestingly enough, this sofware package does not use Expanded, Extended, or High Memory above 640KB RAM. Instead, it uses disk caching, like memory paging or swapping to disk. So you do need a hard drive. I brought out my old KoalaPad hoping it could be used with the software, but TurboCAD only works with real digitizers.

Back in the day I regularly used a program called "ProDesign 2" on a Tandy 2000 at work and my XT at home -- off DD 5.25" floppies, so the Jr. being up to the job isn't exactly a shocker to me.

Compared to most games, even back then, 2D CAD is a tinkertoy.