An Odd Home Computer From The 1980s

If you were around when the Altair 8800 was king, you might remember the name Cromemco. They were an early vendor of add-ons for the Altair, along with companies like Godbout and Morrow. The company was mostly famous for a very crude digital camera for the Altair and a similarly-crude graphics interface card. They graduated into building S-100 bus computers. Like many similar companies, they could taste the upcoming home PC market, and they wanted a piece of it. Their answer? The $1,800 C-10 Cromemco Personal Computer, and you can see [Vintage Geek’s] thoughts on the odd machine in the video below.

The system ran CP/M and, like many similar systems, got lost in the rush to get the IBM PC. Compared to other computers of the time, the C-10 was compact. The keyboard layout seems odd today, but there wasn’t really much standardization in those days.

The video doesn’t feature as much of a teardown of  the machine down as we would have liked, but there were a few peeks inside the monitor. They first tried powering up the computer live on the video. The screen lit up but didn’t show anything legible. We wish they had eased the voltage up on the old machine since we are reasonably certain the power supply capacitors are shot. With luck, they didn’t fry any of the components. But we hope they will get it running soon.

We didn’t remember the Cromemco C-10, but that’s not totally surprising. There were many computers that came and went during that time, from the Sol-20 to the nameless prototypes that never made it to market. If you want to see what a webcam looked like in 1975, be our guest.

17 thoughts on “An Odd Home Computer From The 1980s

  1. It was a funny time ln the early 80s. The z80 and 68000 were going multi user with mp/m and early unix like (cromix?). Even Ohio Scientific had a multi user is for the 6502 (os/65u).

    Then came the ibm pc, single user, no network. It was like going back in the dark ages.

    Not too much later sanity arose with sun workstations, running bsd.

    1. “Then came the ibm pc, single user, no network. It was like going back in the dark ages.”

      Not only that, the limitations of DOS and the popularity of the IBM PC lead programmers go off course.
      In the CP/M and MP/M days, applications were well behaved.

      They used CP/M functions to for i/o, which allowed applications to be portable.

      With the exception for the CRT and terminal device, maybe.
      Bigger programs had configuration files, to cover popular terminal types.

      There also was GSX, a hardware-independent graphics library/API.

      Unfortunately, the IBM PC BIOS and DOS didn’t feature something comparable.
      So many applications went with the most basic video (CGA).

      Tragically, it didn’t have had to be like this.
      Before the IBM PC was somwhat dominant, there were MS-DOS computers, so called “MS-DOS compatibles” which had their own, enhanced architecture.

      Models lile the Sirius-1/Victor 9000, Sanyo MBC-550, Triumph Adler Alphatronic PC-16, c’t 86 PC

      Unfortunately, they became a footnote in history when programmers without manners started to directly support the IBM hardware (exclusively!).
      If they had at least included a hardware-independent fall-back for things like video memory access and serial port i/o..

      1. Put the Tandy Model 2000 in that list. Moving up to an 80186 (hey, one step at a time) it brought a fully MSDOS compatible system while moving in an improved hardware direction.

        Unfortunately, it, and numerous others including the ones you mentioned, were “MSDOS-compatible” and not “Lotus 123″ or Flight Simulator” compatible (at least not with the IBM PC binaries which diddled with hardware for improved speed) so they were seen as “lesser”.

        Too bad, things could have turned out differently…

        1. The entire pc market did everything in very simple steps milking every last dollar before making a single step progression, like cdroms, 1x 2x 4x 6x 8x 12x 16x milking each advance for all it was worth before inching farward

  2. In 1984 I did a lot of embedded Z80 assembling on a Cromemco Z2D (running CDOS – CP/M work-a-like) with 64K of ram, twin 8″ floppies and a huge Logabax serial printer. It was the cream for a long time.

  3. I remember a store in NYC that sold earlier Cromemco gear than the machine in the video. This would have been around 1980. It was big, heavy, and for the time, very expensive. As I recall, its unique feature was color in a world of black (or green) and white displays.

    The video (at least the parts I didn’t scrub over) was disappointing. I agree with Al that whoever the Vintage Geek is, he sure doesn’t have a clue when it comes to properly handling vintage gear. It’s frustrating to see some random idiot take a pristine bit of antiquity and then just plug it in and let it rip!

    1. If you find yourself in possession of a piece of vintage gear that been unused for more than a decade, resist the urge to plug it in and try it out! The electrolytic capacitors in the power supply will, at a minimum, have lost their polarity. In the worst case, they will leak DC current up to the point of being a 0 ohm resistor. Power one of those babies up and… BAM! Blue smoke everywhere. Best case the gear won’t work like this Cromemco machine because of AC all over what should be DC supplies.

      Leakage test, reform or replace those capacitors first! You’ll thank me later.

      1. Reducing the AC voltage to reduce the stress on old electrolytic capacitors works on equipment with a linear power supply.

        But this unit has a switchmode power supply. A low AC input voltage will either cause the power supply not to start at all; or it will output full output voltages. At best, a low AC input might protect the big 200v filter caps in the switchmode power supply.

        If I had to test this particular computer, I think I’d first check for any signs of swelling or leakage on the capacitors. Replace any that look bad. Then unplug the logic boards, and power up the switchmode supply by itself (with reduced AC input voltage). Measure all its output voltage to be sure they worked.

        Then check the resistance to GND on each of the supply voltages. If it’s excessively low, look for shorted caps. If the resistance is OK, use bench supplies to power the logic boards by themselves. Again, apply reduced voltages, and check for any bad capacitors.

        Only after all this checks out OK, would I reconnect and power up the entire unit. And you may still get a *bang* from some electrolytic or tantalum cap!

    2. Vintage Geek owns a large retrocomputing museum in Tennessee and likely knows what he’s doing. Perhaps he did a proper checkout prior to shooting the video and what you are seeing is dramatic license.

  4. When I was an EE graduate student at Stanford my advisor and his office mate were the founders of Cromemco. At the time the graduate engineering dorm was Crothers Memorial Hall. I always wondered if that was the source of the name of their company.

      1. I kept trying to join the Home Brew Computer Club but I could never figure out where they met. It seemed like they jumped all over and it always conflicted with a class.
        When I got burned out studying and needed a break I drove down to the Byte Shop. I believe it was the first personal computer store anywhere. Anyway, I was looking at an Apple 1 in all its glory when the owner walked over. I knew him and when he told me how much it cost I knew I couldn’t afford it. I was eating rice to fill my stomach so it was a no go. Since he knew me he offered to give me the address where they were making them. He said I could go talk to them. I passed since my class load was so heavy. Makes me think what could have happened. lol

  5. This is sooo cool and very beautiful, including the large components. The keyboard looks perfectly fine and very standardized, don’t know what the author’s on about.

    I’m very much of the “wait for the caps to fail” school of thought. It’s not like they’ll be unavailable (or unmakeable) After the Pulse.

  6. I still have my Cromemco Z2 with Morrow dual 8” floppies boxed up in my garage. 56K RAM. It was a true work horse. Super reliable. Someday I’ll have to take the time to restore it. And yes, I know about capacitors…

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