That's very visually similar to a Northgate keyboard I had once. It's nice to see that there are actually companies starting to make decent keyboards again now as people actually seem to have realised how horrible the plastic mush we usually get these days has got.Hell Razor5543 wrote: 24 Nov 2019, 18:01 I like it when things are properly and solidly built. One of the best keyboards I have ever used was the Windows 95 keyboard (with a 5 pin DIN plug) from Fujitsu. If you were the sort of person who typed as though you hated the keyboard all that would happen was you got sore fingers (oh, and the keyboard worked properly nonetheless). I have taken it apart to clean it. From top to bottom it went;
Top casing,
Matrix casing (with LOTS of screws holding it to the steel backing plate),
Key cap,
Key head,
Spring,
Spring cup,
Rubber membrane,
Upper contact membrane,
Separator membrane,
Lower contact membrane,
Steel backing plate,
Bottom casing.
If you have ever seen the film "Wanted" you will know that James MacAvoys' character hits Chris Pratts' character with a keyboard (breaking the keyboard and, I think, knocking out a tooth). If he had used a Fujitsu keyboard there would be a lot more in the way of injuries, and the keyboard probably would still be useable!
Northgate Omnikey Ultra was probably my favourite keyboard, sadly I lost that when IT upgraded my workstation at work when I was out of the office and binned it. Furious didn't even come close!
Close second was the board in my old Toshiba T5200 portable - unsurprisingly as it uses the same Alps key switches as the Northgate board.
Third is the ubiquitous IBM Model-M. There's a reason they're so sought after, and still being produced. They are lovely things to type on, and nothing feels quite like a buckling spring board - though they are incredibly noisy!
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That's the bigger brother of the little Crypton Motorscope 335 that is currently in my garage.Gibbo2286 wrote: 24 Nov 2019, 20:47 This is a version of the one we had, a bit later than ours and not as pretty ours was in a red cabinet.
...Same multimeter that I use for most things too!
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Today was the day to get all the digital cards out for a check over and to get everything reseated.
So here are the digital boards, from left to right.
"CRT" - This is responsible for taking the data from the computer and converting it into a composite video signal which is fed to the monitor.
"MUX" - Handles all the analogue to digital conversion, signal processing and such like. Initially I thought "oh my god bodge wires" when I saw this, before realising those wires are all shielded coax, so they have just decided it's a more reliable way of getting a clean signal across the board than using PCB traces. Even if it does look a bit shonky.
The whole machine is astonishingly free of bodge wires actually...especially for a design from the late 70s where they usually would find *something* after the board's had gone to be made...
Lovely white ceramic package on the ADC.
"I/O" - No great surprise, does most of the heavy lifting with regards to the actual I/O side of things.
"CPU" - Unsurprisingly, contains the CPU and the 64kB of RAM it makes use of.
"MEM1" - Basically all the ROM. Interesting to see that while these initially all look to be EPROMS, they're not. While there are some, there are also a shedload of character generators. My guess is they're using this to give greater control over the display without going to the lengths of full bitmap control.
"PP" - Pre-Processor. Not actually entirely sure what this does, though I have to assume basically just does some general housekeeping which we would normally expect to be handled directly by the CPU these days... purely a guess though.
The EPROM here was losing its label, so a bit of black tape was applied to help keep the data safe.
Probably the main reason I would love to find an actual service manual for this (VERY unlikely as Sun kept really quite tight control over) is that it would probably give me a really good breakdown of the actual system architecture - sadly there's a lot of hardware in here I've never worked with before, so there's a learning process involved.
All of the socketed components on these boards were reseated while I had them out, as I knew this had already sorted one problem.
Turns out that while it's not fixed everything (the gas analyser is still failing the self test), it has definitely helped. Previously we had complete nonsense shown on the voltage readout. Now however we seem to have sensible data shown.
The column on the right is showing the data from when I had a car battery connected to the voltage measurement lead, the one on the left is with the leads shorted together. Had to do that as it's smart enough to know when there's nothing connected and will just blank the display for that measurement. Helpful in the real world...but slightly awkward during testing!
Not worrying too much about a 0.2V offset at zero for an instrument of this type, the reading with a load connected was spot on...multimeter was showing 12.23V.
Worth noting that we appear to have more sane readings on the vacuum gauge as well now, that was tending to wander around quite a bit at rest too.
Definitely progress.
Know this is repeating myself to some folks I've spoken to about this, but I figure it's worth mentioning one of my plans for this thing long term to the world at large. One of the useful things about the monitor the computer is that it's simply a self-contained composite unit. The signal from the computer to it is simply carried by a twisted pair of wires. So it would be a truly trivial task to cut into that and introduce a switchable video source.
My intention here is to fit a small self contained computer (probably a Raspberry Pi because I know I can just throw Debian at it rather than having to muck around with it) somewhere in the case. This would then allow me to use the monitor there to view manuals, data sheets, instructional videos etc in the garage on something a bit more user friendly than a tiny phone screen. It's a really nice sharp screen so should do just fine.
I'll do doing nothing which cannot be reversed easily. The only thing I'll need to fit to the outside of the case will be a switch to change video sources. Luckily I won't even need to drill a hole for that as there's a convenient rubber bung by the remote control input for an option port...so I can just put a hole into that rubber bung rather than drilling a hole in the actual case.
Just seems a really nice way to bring it functionally into the 21st century somewhat to help it perform the sort of tasks it was originally designed for. Quite often I find myself in the garage with a wiring diagram of something open on my phone and getting really fed up with the screen turning off every five seconds...so having a fixed screen which I can't drop under the car will be most appreciated.
So that's what will be getting done to improve it in addition to the actual service and repair work.
