SCELBI 8H Usability Reasessment

For a long time, I would say that the SCELBI 8H was the first practical computer marketed to the general public. The key word being practical, as certainly many of the other personal computers of the day, were not very useful machines, other than for educational purposes, at least without adding additional capabilities to them.

From the time that I got my reproduction SCELBI 8H working, I’ve been able to demonstrate a number of interesting, practical applications on it. That I was able to do so, was justification for the claim that a SCELBI 8H was a “practical” computer. However, I’ve always used a second computer to assemble the source code and then downloaded the application to the SCELBI through a serial port. A few months ago, when I talked to Bob Findley, I asked about how they did application development for the SCELBI 8H. It turns out that Bob and Nat used almost exactly the same approach that I used. Only thing is that they used a PDP-8 as a platform for the cross assembler and a teletype with it’s paper tape punch/reader to download the program to the SCELBI. Though the cross development platforms are different, what Bob and Nat did, was essentially the same as what I’ve done.

I’ve come to realize that though you can run some interesting, practical applications on the SCELBI 8H, it really can’t do it, without either help from a host computer, an impractical amount of time, or the addition of features like a built in monitor. After talking to Bob, and thinking about it a bit, I guess I’m ready to say that though the SCELBI 8H, as shipped, can run practical applications, it was not a very practical stand alone computer. However, that still doesn’t remove the significance of the SCELBI 8H as the first offering from one of the very first personal computer startup type companies.

Note that the limited capabilities of the 8H were recognized by Nat and Bob, who developed the follow on SCELBI 8B, with it’s extensive built in software suite. More about the 8B in a follow on post.

3 Responses to “SCELBI 8H Usability Reasessment”

  1. Jack Rubin says:

    If you can come up with the PDP-8 cross-assembler, I’ll trade you a PDP-8 for a SCELBI kit! Would Mark Arnold or Bob Findley have access to it? Very cool, especially considering the photos of Nat’s PDP-8/E!

  2. Marco says:

    Interesting comment, but I remember back then writing applications for my Kim-1 with only pen and paper… couldn’t this also have been possible for the SCELBI?
    By the way, are you still demonstrating your SCELBI unit at VCF West this weekend? For some reason your name was taken off the exhibitors list…

  3. Mike says:

    You can program the 8H with the front panel, but just to get an idea of how difficult it is to use, before I added the EPROM monitor, it took me 10 to 15 minutes to enter the 37 byte boot loader that I wrote. Sophisticated programs, would be extremely difficult to get up and running and require extensive amounts of free time. Sorry, I will not be at VCF-west this year.

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