What did you do Today 2018

Modern stuff needs batteries. At school we were shown how to use a Curta calculator. Lovely engineering.

However it was cheaper to have electronics as a hobby than engineering so I built a Sinclair in 1975 and a microcomputer (6800 based, 256 bytes RAM, 8 switches and LEDs for data and 8 for address) in 1977. Met Sir Clive in 1980 at the first London Computer Fair at the Polytechnic of North London.

After machining quite a bit of cast iron, I thought my poor little Sieg X2 mini mill needed a bit of a clean and oil. So I did. Only real surprise was that the X axis (?? side to side) leadscrew was supported by two thrust races. After ten years the slides definitely needed some oil, but they were clean with no apparent wear. So everything got a good wash, clean up oiled or greased as required and re-assembled. Everything now feels silky smooth, backlash free and good.

Happy New Year

cheers

Bill

ps Isn't cast iron filthy stuff!!

Edited By Bill Pudney on 04/01/2018 02:26:54

I went on an archeological dig. During two hours of careful work, a large number of 5C collets, tool holders, CBN and carbide inserts, nuts bolts and other historical artifacts were unearthed. The last, and most exciting, artifact to be found may be a lathe chip tray. Positive identification is still awaited, since this artifact has not seen the light of day for at least several years.

Cleaning the workshop up then?😉

Speak not of Sinclair, grrr.
I spent several summers picking black currants to fund the purchase of some Sinclair hi-fi modules, none of which ever worked.
I assembled them as per the instructions, even had a sparks check it over for me, nothing...

Decades later I mentioned it to Clive at a mensa dinner, no reply

Yes, I remember the stuff - great claims of the power output - by careful selection of words e.g. using terms like peak power it was possible to claim the modules were amazingly powerful. We used to joke about there being average power, peak power and Sinclair power!
Having bought a small module boasting 20W audio power, looking like a heat-sink filled in with black gunge, I powered it up and fed it with audio tone. It lasted well under 30 seconds. I conducted a post-mortem and found gunge had got between the collector of one of the output transistors and there was little thermal conductivity.
I also bought a ZX81 with added memory module - the latter bobbed up and down at the connector and crashed the computer regularly.
Sinclair - I think he is a genius who produced mainly rubbish. I hope he inspired others. Take heart though, the motors from the C5 are great for motorised bogies for models.

I understood that C5 motors were Electrolux components from their washing machine range.

I resisted buying one despite the hype; as well as being slow, positively dangerous in traffic, limited in range and having little weather protection, you needed to be "Billy No Mates" to drive one. (And if you weren't at the start you soon would be.)

Jim

Edited By Jim Nic on 04/01/2018 10:35:32

Anyone remember the upgrade kit to the ZX spectrum to the spectrum+? The latter had a QL-style case with better keyboard - the kit was basically the case and keyboard, you swapped your Spectrum motherboard. Anyway I heard from someone who worked for Sinclair Research that WH Smith's service policy for people returning Spectrums was to basically replace them since the failure frate was so high and they didn't have the support expertise, sening the ruturn back to Sinclair. Sinclair found they were getting quite a number of Spectrum returns that turned out to be empty cases - people had twigged on to the WHS policy and worked out a little scam.

I did Sinclair's stereo amplifiers c1973? Worked for approx. 2 seconds then were no more. With hindsight I thought I got the PSU wrong, but maybe I was an innocent bystander

Bazyle, I still have a Curta calculator, in pristine condition, it was my fathers he was a surveyor by profession and used it for what were then complex calculations but nowadays are relatively simple using modern calculators, he bought it during the 50’s and I inherited it from him about 30 years ago.

Dave W

I had a Sinclair amplifier for about 5 years power supply, pre-amp, tone controls, rumble&scratch filters and two 20W power amp modules. It was quite reliable apart from needing a regular supply of BD138 and BD139 output transistors! Very marginally rated. Everything else was ok apart from the cheap build quality. The wooden case I put around the home-built aluminium chassis made it look quite smart.

Back in the early 80s, Sinclair had an office on King's Parade in Cambridge, opposite the college of that name. I was an engineering student at Trinity at the time and one day I called in to have a look, as I passed it several times most days. I'd experienced some of their questionable audio gear previously and was curious to see what they were up to. It was lunchtime and clearly they all nipped out for lunch, leaving the door open. I went in anyway and had a sniff about. They had a couple of small rooms above the ground floor shop, each with a desk (or two?). Nothing technical to be seen, so clearly just an admin office. But all the way up from the front door, the stairs were piled high with returned products. I guess that was pretty much what I expected. I doubt the vast ego himself would have been there anyway.

I always found Sinclair an embarrassment, speaking as a British engineer. This was a time when we were being exhorted to buy British Leyland crap like the Metro, so stakes were lowered and he joined the race to the bottom enthusiastically. Last I heard from him, he was proposing fuel cell powered helicopters(!) - what a deluded fool. Seemed quite appropriate that he craved support from the likes of Mensa, a self-selecting, self-promoting group of snobs.

Murray

The Curta reminds me of a thing we had in the DO in my first real job. You set it up by manipulating levers in accordance with some arcane ritual (probably involving phases of the moon and chicken bones), wound a hand till a bell rang, then wound it back one rev and read the answer off. The first electronic calculator we got at work was the size of a book and you had to sign for it in the chief engineers office. At the end of my career if the batteries in you calculator went flat they would just issue an new one, I'm not convinced they knew you could fit new batteries!

Haha my dad got one of their preamps with an optional "scratch and rumble" filter board. The key characteristic of the latter was the deafening noise it made when you turned the crappy plastic Sinclair knobs. This was almost certainly due to the use of preset pots for level adjustment instead of pukka potentiometers that are designed for frequent adjustment. He wasn't best impressed with his investment, having spent ages constructing a proper enclosure and PSU for them. I recall the box being lined with silver foil in an unsuccessful attempt to reduce the hum levels. I know he also had to return the actual power amps early on. And I'll never forget the turn-on thump!

I recall blowing a load of pocket money on a pair of his TDA2020 audio power IC kits that were described as indestructible. You can guess how that ended up. They were little more than a std IC from SGS, supplied with a single sided PCB. Very little information about how to heatsink them properly and of course, no heatsink was offered for sale with them.

Murray

Jim nic

it was hoover washing machine motors powering the c5`s kept the hoover factory afloat in Merthyr tydfil for a few extra years.

brian

Brian

Crikey! I didn't imagine Sinclair sold enough of the things tokeep a factory going for more than an hour or 2. Still, at least it was made in UK and every little helped.

Jim

Too true, I only ever saw one on the road, pulled up to some traffic lights with a dirty great HGV alongside it, the lorry driver had got no chance of seeing the C5 at all, what it was going to do when it pulled of, turned or whatever. Was frightening to watch, you'd have to have a death wish to actually ride one on public roads..

Edited By Mick Berrisford on 04/01/2018 12:49:57

Edited By Mick Berrisford on 04/01/2018 12:50:36