(Luckily, we saved his page before it vanished from the web).

Bob Withers CoCo Graphics Adventures with Source Code and Maps!

Install the VCC CoCo Emulator to play these CoCo games Right Now!

Welcome to my little space on the web. The picture above may appear a little fuzzy but it is actually crystal clear. I’m just a fuzzy person!

Once upon a time, in a previous life, my friend, Steve O’Dea and I developed a series of six graphic adventures for the Radio Shack Color Computer. These adventures were marketed by Mark Data Products and were considered rather revolutionary for their time. The adventures stored all images compressed in memory and were usable from cassette based systems as well as from diskette. These games were all written in MC6809 assembly language and assembled with the fantastic Micro Works MACRO-80C assembler. To this day this is one of the best assemblers I’ve ever used.

A little known fact is that these adventure games were also ported to the IBM/PC using a CGA graphic screen. These versions entered the market too late and did not take full advantage of the available hardware and were not widely distributed.

You can read an interview with me about the CoCo adventure days here. Walkthroughs of all the games have been compiled by Ricardo Mendonça Ferreira and are available here. While developing these games I would always draw a game map to work from. This map would assign a number to each room in the game and identify direction and object placement. Sadly the maps for Trekboer and Vortex Factor have been lost.

• Before blindly grabbing all of these files: All Coco binary files have been replaced with Robert Gault’s modifications that save and load game positions from disk rather than tape as in the originals. The source code files are the originals that use tape. Also, a missing source file called ASCLNO.ASM has been recreated so the games can be assembled correctly.
• Like MANY CoCo 1 and 2 games, these games make use of the artifact color set which causes red and blue colors to appear on a composite monitor even though only black and white pixels are actually used. Most CoCo emulators generate the same artifact colors while a real CoCo allows you to hit RESET and cause red and blue to be swapped for the generated colors. Either way, you’ll have to hit ENTER to get past the artifact color selection screen you see at the start of some of these games.

Bob Withers holds the following programming certifications: