Happy 45th Birthday to the Sinclair ZX81!

Release Date: March 5, 1981

@tsturm Yes! With the massive add-on memory pack of 16K
@tsturm
I wanted one, so badly.
I fantasized about the printer even.

@mistergenest I can pretty much remember the day I saw a version of this ad in mid-1981. It was like "I SEE THE FUTURE".

Scraped together my pocket money and had a ZX81 shortly thereafter.

@tsturm My first computer complete with 16K and rubber band to stop it wobbling and crashing.
@donald_brady The 16K extension was a strong early education in saving your work and thinking about backups.
@tsturm It looks cheap, I guess.
@tsturm That was before I got involved in the #Cambridge micro industry. I did a lot of work on the ZX83 (the Spectrum was the ZX82 and the QL was the ZX83, at least as far as the numbers printed on the custom chips were concerned).
@TimWardCam Oh wow - that's awesome! I had a QL and used it quite a lot for some time after it came out. What kind of work did you do on that machine?

@tsturm I worked for GST. The main thing we did for Sinclair was 68K/OS, which they never used - but I got three trips round the world and a new kitchen out of it. We also did some software products to go with the QL as released, which sold in small numbers but allowed me to claim that I've authored a book that you could buy in shops - the user manual for the assembler. I also spotted a bug in one of the QL chips during development and got them to fix it.

I ran a project to rework the QL hardware to make a financial information terminal for Australian Associated Press, which is where the trips round the world came from, allowing me to visit Ayers Rock, Singapore, Hawaii and India on the way there and back.

I pressed some of the buttons during the press launch of the QL. But we'd had an awful lot to drink the night before, followed by Bucks Fizz on arrival at the press launch, resulting in me missing a cue so Clive had to repeat it.

That's my handwriting on at least some of the labels on the picture. https://en.wikipedia.org/wiki/68K/OS

You can't have that much fun as a programmer these days.

68K/OS - Wikipedia

@TimWardCam You are pretty much credited with writing 68K/OS - that's awesome! And I'm honored to meet you.

I actually at one point was using the GST Assembler on my QL... but it was kinda late in my intensive use of the machine just before I moved on to an Atari ST.

Yes, programmers back then could still build full a full OS from scratch, which is not possible on modern hardware nowadays. I had a chance to help build a multitasking OS on 68030 CPUs around 1990, which was a great experience.

@tsturm I did much of the design, but there were half a dozen of us writing the code. The challenging bit was to find something for the boss to write that was interesting and important but not critical path, as he kept having to stop writing code to go off and do boss things.

@TimWardCam In my case it was a team of about 6 core developers.

I was helping to set up a computer lab at a company of a friend of my parents as a weekend job and I was like - "Hey these Mega STs are cool, I'm writing some games in assembler on my ST!"

The programmers stopped what they were doing and all looked at each other, then looked at me. "Do you want to work here for the summer?"

That's how I ended up spending an intense summer writing I/O chip drivers in 68K assembly. 😁

@tsturm Oh yes, the ST as well, that was fun too.

https://en.wikipedia.org/wiki/1st_Word

1st Word - Wikipedia

@TimWardCam Oh wow. I had forgotten that this was also a GST product. 😲
@TimWardCam Is there a written history of GST and its impact on that era of computer history?
@tsturm Not that I'm aware of. We were just a bunch of kids having fund and being paid for it.
@TimWardCam That's the best way to do it.
@TimWardCam Talking about this puts me into a nostalgic mood. 68K systems were so much fun to program for. A great clean CPU architecture. 😊
@tsturm Give or take when you put odd numbers into an A register on one of the earlier chips ... but yes, much cleaner than anything else that was around.
@TimWardCam Nothing is perfect, but in university they made me learn x86 assembly and I will never complain about any other assembly language after that.

@TimWardCam "I pressed some of the buttons during the press launch of the QL. But we'd had an awful lot to drink the night before, followed by Bucks Fizz on arrival at the press launch, resulting in me missing a cue so Clive had to repeat it."

That's a great story! πŸ˜†

@tsturm We were on our third G&T each before we spotted the little card on the table which said "all spirits in this bar are sold in doubles". And then we had the chef's tasting menu which came with various wines with the various courses. Intercontinental hotel, Park Lane.
@tsturm
This is how it all started for me.
@koehntopp It's one of the few computers from that era that I never really had a chance to do much with. It sure started it all!
@tsturm
It is about in the middle between the first freely programmable computer (Zuse Z1, Patents date 05/1936, prototypes older) and today!
@vampirdaddy True! Those early 8-bit machines were such a dramatic change in how computing looked - before it was a room full of giant machines, and now suddenly it was a small box in front of the TV in the living room.

@tsturm I wrote my first lines of Basic on a ZX81.

Long, long time ago.

@otmar Yep, same. It's incredible that it's 45 years. What a wild ride!
@tsturm 'twas not my first computer but a classmate had one so it was the first one I met in person 😁
@tsturm My first computer, writing in basic and saving to cassette.

Owned one!

With a 32kB memory expansion!