First Computer Memories with the Sinclair ZX81

Some people have an inordinate fondness for their first car. For me, it is my first computer. In Junior High School, I wanted a computer so bad I could taste it. What use did I have for a car? I was a geek and unlikely to get a date. I used to read Sky and Telescope magazine, and in the back they always had an advertisement for a new computer. This was in 1980, before PCs were mainstream. It was called the ZX80. That name caught our fancy. I had a close friend who wanted it as badly as I and used to dream about having my own computer, one small enough to fit on my desk. One that I could program any way I wanted to. The ZX80 came in both kit form and assembled. That year came and went and we never did get our hands on a ZX80. The price tag of $100 was way beyond our means.

In 1981 a new model appeared in the back of that same magazine: the ZX81. For those of you old enough to remember, and who really care, Timex bought Sinclair, who made the ZX81, and renamed it the Timex-Sinclair model Ts1000.

My father was all for education and felt a computer was very educational. He eventually bought me a ZX81 for a steal at $50. Wow! My own computer. I had taken computer courses at the local universities (on mainframes) and had learned the BASIC programming language. Fortunately for me, that was the language the ZX81 used. I still love BASIC, although Visual Basic gives me headaches.

But about the little black jewel. It was small and weighted just 12 oz. It was small enough to fit in my hand. The ZX81 came with no monitor attached. The computer was designed to use a black and white television as the monitor. Fortunately, back in the early 80's, black and white TVs were not hard to find. The attachment was via a VHF/UHF switch. I used to love flipping that switch and watching the computer boot up. Everything is exciting about your first computer.

It only had 1K of RAM, and yes, that's kilobytes not mega- or gigabytes, of RAM, but there were 8KB of ROM. Just how useful could that be? Well, with a lot of imagination and efficient programming I was up to all sorts of things. The best was programming games. Unfortunately there was no internal storage media. This computer was designed to store programs in a pretty old fashioned way -- on a cassette recorder. You would hook it up to the cassette player, hit record and the computer would make sounds like a modem, for those of you old enough to remember what a modem sounds like (it's sort of like a fax machine). Then, you would write down how many feet of tape that particular program resided on. Reading the program was done in reverse. Forwarding the cassette to the proper feet of tape, telling the computer to download a program and playing the tape the same as if you were playing Joan Jett.

The keyboard was very different as well. First of all it was an all membrane keyboard. No real tactile feedback. And, when you programmed, you could not just type in any old letter, each key performed a different task such as "print" or "for." That kept mistakes to a minimum and made the programming much much faster.

I used to mow lawns the same time as I got my first computer. We lived in Texas and it got hot very early, so I'd be out mowing at 6 in the morning programming as much in my head as I could. I just could not wait to get home and get it all on the computer. To this day, if I smell carbon monoxide, computer code runs through my head. Call me crazy.

As soon as I could, I bought a memory expansion of 16K that hooked onto the back of my computer. It was great. I could program longer and longer code. The problem was I had about 20 minutes before the behemoth, it was half as large as the computer, would heat up and shut down the computer. But it was still cool.

The experience of my first computer left me enthralled. I was young and full of wonder. Nothing else came close to bringing me such joy back then.

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