Keeping yesterday's computers ticking takes more than nostalgia
Earie Salmon explains why soldering skills are only the start
ARCHAEOLOGIC Repairing and restoring vintage computer hardware has grown increasingly popular, but keeping decades-old machines alive presents different challenges from fixing modern kit.
Earie Salmon, of the YouTube channel Earie's 8-Bit Workshop, is one of many tinkerers documenting the process of keeping retro computers ticking over and building new examples of obsolete or never-released kit.
Based in Australia, Salmon's entry point into the hobby is all too familiar – a bit of nostalgia mixed with "what would I like to have had if given the chance".
My biggest frustration with sourcing parts are counterfeit chips. You will confidently order a big bag of 74LS logic ICs to find they are in fact not 74LS.
Worse, most IC testers will say 'oh yes it's a 00 IC and works fine' but it's had the label sanded off and re‑etched, it's a different family of logic chips and won't work in your computer
In the early 1980s, his brother had a ZX81 and Commodore VIC 20. "I was somewhat jealous and he rationed my access," recalled Salmon. The experience clearly stayed with him. "I bought the system I would like to have had at the same time he had his ZX81, an Acorn Atom, then on into the realms of C64 and Amiga."
"However, the personal connection, or at least tenuous link, to the computers after that point disappeared when I realized I had the makings of a collection."
The collecting bug bites plenty of people in the tech industry, and Salmon reckons he currently has between 35 and 40 systems "in various states of disrepair."
These days, Salmon is an IT professional and refreshingly agnostic about retro hardware. "Repairing half a dozen BBCs or Spectrums in one hit gets a little dull," he said, preferring to plug holes in his collection, or even build computers from scratch. "Last year, I built a notional successor to the TI‑99/4A, the TI‑99/22 designed by Dan Werner, and an Acorn Atom replica designed by Hackjunk."
Skills-wise, readers will be unsurprised to learn that knowing your way around soldering and desoldering equipment is a prerequisite, although Salmon cautioned against grabbing some vintage hardware and "cracking on." Better to practice on a Vero board with some disposable components before hitting something decades old with components that might be decidedly difficult to track down.
"Finding parts is definitely the biggest challenge… Anything custom, any custom IC such as a ULA that hasn't been built since the production stopped on the original computer.
"Getting hold of some of these parts isn't too bad but a lot of them are now only available from 'dead' systems. It just seems wrong to harvest parts but it's unavoidable now."
Salmon acknowledged that there were modern replicas of some devices, but many rarer computers lacked the same support.
"My biggest frustration with sourcing parts are counterfeit chips. You will confidently order a big bag of 74LS logic ICs to find they are in fact not 74LS. Worse, most IC testers will say 'oh yes it's a 00 IC and works fine' but it's had the label sanded off and re‑etched, it's a different family of logic chips and won't work in your computer. I learnt that one the hard way."
Then there are the schematics. Learning to read them and see what should go where is another core skill Salmon recommends, assuming the documents can be found in a language the repairer understands. "A lot of the Japanese computers, NEC or MSX, say, not only were the designs never published but the documentation isn't even googlable unless you know Japanese as it's not been translated."
Salmon's most rewarding work involved a BBC Model B. "Had I known what I was letting myself in for, I might not have started it, but once you get the cover off you feel sort of obliged to get it running again," he said.
The repair involved undoing somebody else's efforts: bodge wires running to the wrong places, blown ICs, broken traces, and more. Salmon reckons that some of the soldering had been done with a hot spoon. "I don't want to talk anyone down," he said, "but… their confidence exceeded their skills." Best not to look at some of the Raspberry Pi computers this writer has destroyed over the years after experience took a back seat to enthusiasm.
Salmon has strong feelings about the repairability of modern hardware, which makes the '70s, '80s, and '90s seem like a golden age. "Equipment designed from the mid-noughties adopted the 'look how small we got it' approach which coincidentally, and almost certainly with no intent, also results in 'look how unrepairable we made it, this is fantastic, now we can force everyone to buy a brand new phone/laptop/tablet every couple of years.'"
"In the Nineties and early Noughties, computers were really quite modular so if a bit broke then you only needed to replace that part where previously you could replace the component.
"Then from mid-Noughties, the replacement part was suddenly the whole unit. Where previously electronics would be built to last say ten years because you wanted as few returned in the first three as you could get away with, now you want it to last only for the warranty period plus one day. The science behind that to calculate just the right life span of components must be crazy!"
Salmon is, unsurprisingly, a huge supporter of the right-to-repair movement.
Finally, Salmon's biggest "don't" for budding repairers concerns plugging in the hardware. "Don't work with mains voltage until you know what you are doing and always keep the mains voltage covered to prevent you accidentally touching it."
"It's probably happened to everyone who has worked with electronics where you concentrate on placing a probe and your hand accidentally touched a high‑side power component, so get it out of the way or cover it! It might be the only mistake you ever make." ®
Originally published on The Register