The Colecovision console from the early 1980s is probably not the most memorable platform of its era, but it retains a retrocomputing following to this day. The original hardware can be a bit pricey in 2023, so [nanochess] has built one of his own on a breadboard. It’s fully functional from original Colecovision cartridges, and we see it in the video below the break running Frogger.
Behind the mess of wires is a surprisingly simple circuit with only a few logic chips beyond the Z80 processor, the various memory and EPROM chips, and the video and sound chips. We’re told the complexity is considerably reduced by the use of a Texas Instruments TMS9118 video controller instead of a 9918.
Had we been building it we would probably have taken the less brave step of using color coded wires for the various signals, because we remember the fun and games associated with wiring old-style 8-bit computers by hand only too well. But we have to admit that it reminds us of a lost youth working out Z80 address decoder schematics, so it’s very pleasing to see one built today.
If you’re hungry for more Coleco goodness, this isn’t the first home made Colecovision we’ve brought you.
OMG
I worked on end of the line test equipment for power supplies and printer logic PCBs back in the 1980s, one of my first jobs after spending 4 years in the US Air Force. Coleco had a great design at the time and could have made a killing but……
One day my test equipment was failing everything coming off the power supply line. The manager assumed that there was something wrong with my test equipment but there was actually a problem. One of the assemblers was installing an electrolytic cap in backwards and the DC tests were failing for ripple. During the test, the PCB was only energized for a few seconds, I discovered the problem when a cap exploded in my face as I was troubleshooting the Test Equipment and had the PCB energized for ~1 minute, surprise!!!. They still sent thousands of PCBs out that they knew were bad that got assembled into final Adam computers.
Needless to say, people were not happy when 1000uf caps exploded on Christmas day when they powered up their Adam Personal computers. I have no idea how many other quality problems they had but they did have a customer return rate of over 50%.
Bunch of off the shelf parts and a case and you can sell it, but can you call it a colecovision?
That’s what a Colecovision is. A bunch of off-the-shelf parts in a box with a specific cartridge connector.