BioTerror! is a turn-based strategy simulation in which you manage resource units to quarantine cities, research a cure, and eradicate infections. The game was written in 2011 for a 1977 Commodore PET 2001-8. This computer only had 8kb of RAM and 40 columns on a colorless screen.
Learn about the Commodore PET 2001.

If this game sounds interesting to you:
  1. Visit
    Download the VICE Emulator and run xpet.exe.
  2. Download bioterror!.d64
    Attach it as a drive 8 disk image.
  3. Type   LOAD "*",8   
    After the program loads, type   RUN
v1.0 commands include:
The idea for BioTerror! began 25 years ago when I was making key-graphic (aka PETSCII) screens on my C-64. After watching the movie WarGames, I wanted to produce my own version of Global Thermonuclear War. I started with the map of the Unites States. I did not have the artistic vision at the time to create a decent map, and since I was only 15, I got bored with the idea and let it rest...for 25 years.

I began programming this game on a PET that I picked up on Craigslist, but my machine died and I resumed coding on a PET emulator available here:

Since I saved the map to tape, I was able to read the analog cassette through my soundcard and convert it to a d64 disk image for use with WinVice. Here's the wav file.

The game concept evolved over the course of a few nights. I wanted more game elements than I could cram into 8kb though, and some of my best ideas were axed to keep the game small enough to run on the original 8kb PET. I cut out the animated intro screen, which was later turned into a loader page as a separate file to save RAM.

I had programmed "Gene Code Mutations" but was forced to remove that feature to conserve memory. Once you found the cure code, it was possible for the code to mutate, forcing the player to research another piece of the code. This also had the nasty byproduct of re-infecting previously cured cities.

Despite eliminating many aspects of the game, I feel that my original concept remained intact. The final product was both fun and time consuming. The game has given me a great platform for introduction to other Commodore enthusiasts, and for me, that has been the real payback for my efforts.

My son and play-tester, Logan, at the 2011 CCAG Show in Cleveland. He's sporting a finely stitched Commodore Hockey Jersey (#8). We had many computers on display, but since the PET was dead, I had to run a video of BioTerror! on my tablet.

The game was transfered from the emulator to tape by a couple different Redditors. Here is the game running on a fleet of PETS by one of those users.

Thanks for your interest in my game!

Jason Grow

Comments or bug reports?

My game in progress, before the death of my beloved PET.

The PS/2 PET keyboard I made to continue my work on a PC. Also shown is the cassette adapter that I used to record a wav file of the map through my PC sound card.

PET keyboard sticker sheet.

Code in the process of being refactored.

A later (but not final) version of the map. I decided to remove some of the city connections to save memory.

Final version of the game showing an outbreak in progress.