Friday, April 11, 2014

Imagination Machine

After getting hooked on the KIM-1 and the intimacy of working with such a small computer, I was desperate to make the leap to a personal computer. It was 1982, so the choices were slim: IBM had a PC, Apple of course with both the II and III, Commodore VIC-20, Atari 400/800, and Timex/Sinclair 1000 are the ones I remember. Of these, the Timex/Sinclair and VIC-20 were the cheapest, but as a poor college student, I needed something that was a far better deal. The VIC-20 was the only one that had a real keyboard that I thought I could afford, and was $300. But then I came across an ad in a magazine for something called the APF Electronics Imagination Machine.

The VIC-20 only had 3KB of RAM, while the IM had 9KB and came with two joysticks (with numeric keypads!) and a built-in cassette tape for data storage, something that was an extra cost on most other systems. Best of all, it was $250! I ordered one the same day I saw the ad.

The wait for the machine to arrive was agonizing. When it finally did, I was like a 6-year old on Christmas morning! Even the cassette storage unit seemed like high-tech compared to my beloved KIM. And an added bonus: The IM had a different CPU than the KIM. The KIM was MOS 6502, while the IM was a Motorola 6800. I had a brand-new assembly language to learn! It even had BASIC, which I also got to learn. I spent so many sleepless nights working with my Imagination Machine, and unlike the university mainframe, my time was not monitored or restricted. Looking back on that now, it was a little like locking up an alcoholic in a liquor store.

With a real keyboard now at my disposal, the first major program I wanted to write was an assembler that could translate the 6800 source programs I wanted to write into the hexadecimal machine code for me. That was the first program I ever wrote that I sold commercially, in a package along with some other utilities and games long lost to history.

In my senior year, I was in a computer hardware engineering class, and for my big project in the class I modified my IM to have 32KB of memory. In the days leading up to the project being graded, the unit started to get a bit twitchy, but held up until the day after it was graded, then died. It was quite sad for me at the time, but it was now 1983. There was a new home computer that came out just a few months prior, one that would possess me beyond all the obsessions with computers and programming I had ever known: The Commodore 64.

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