While unpacking some old boxes the other day, I ran across a computer I hadn't seen in some time. It's a tiny machine with an integrated chiclet keyboard in a cream-colored case about the size of two VHS tapes set side-by-side. I'm talking about the TRS-80 MC-10 Micro Color Computer, of course.
Introduced in 1983 by Radio Shack as an even lower-cost alternative to the chain's larger Color Computer series of PCs, the MC-10 originally retailed for just $120 (about $286 in today's dollars), making it the world's cheapest color-capable PC at the time. Before long, the prices of far more capable competing machines (like the TI-99/4a) fell to a similar MSRP, making the value of the TRS-80 MC-10 questionable. Radio Shack responded by dropping the TRS-80 MC-10's price to $79.95, but because the PC couldn't run software for any other Radio Shack computers, nor did it receive much software support in general, it never took off.
Those issues didn't dampen my interest. The weirder the machine, the more fun it is to collect. I actually have two MC-10 units, both of which I acquired a few decades ago at hamfests (local amateur radio swap meets). Due to the MC-10's limited nature (I could use them to program BASIC, and that's about it), I haven't used one since the late 1990s.
I figured I'd give the MC-10 another shot. I hunted around for the proper 9V AC adapter that could power this tiny beast, and an RCA video cable for an RF connection. I hooked it up to my old Samsung TV, flipped the switch, and voilà: It still worked—well, almost. The machine presented a green BASIC prompt, but half of the keys on the keyboard didn't work when pressed.
When things don't work, I know it's time to get out the screwdriver. A mere four screws (and one warranty label) later, I easily opened this small slice of computing history into two parts. "Cleft in twain," as they said in the old days.
Benj Edwards Once I opened the TRS-80 MC-10, I was able to reconnect the keyboard's loose wires.
Once apart, It became immediately obvious what was wrong: One of the two connectors that hooks the keyboard to the unit's main board was loose, with a few wires sticking out. I'm not quite sure how it got that way, because a jostle strong enough to loosen a connector like that probably would've broken the case. Perhaps it was a manufacturing defect and it never truly worked to begin with.
Benj Edwards My efforts to get a better look at the MC-10's Motorola CPU were thwarted by a soldered-on RF shield.
While I had the case apart, I took a closer look at the motherboard. Unfortunately, the most interesting chips (like the unit's 0.89MHz Motorola MC6803 CPU) were hidden from view behind a metal RF shield that was soldered in place. Wary of breaking anything, I left the shield alone, reseated the keyboard cable connectors, and put the whole thing back together.
Next, I pondered what I could actually do with this obscure machine. Turning the unit over and looking at the back provided a clue: a cassette port!
