Vintage Gould/Biomation K-100D Logic analyzer: Scrap for parts or keep?

[ChristofferB]

Hey!

I've recently gotten a late 70's vintage Gould/ Biomation K-100D logic analyzer.
There isn't much data about them online (apart from complete service manual, which is nice)
and I'm trying to decide with myself wether I should keep it or scrap it for vintage microcomputer parts.
It has a nice CRT with interface board that could readily be reused, and a nice card cage with backplane connectors and some other interesting parts to salvage.

Problem is, it's 16 channels, it needs some active differential pair probes, it seems, and
i have another logic analyzer, the 48ch Thurlby-Thandar LA4800.

So do I keep/use it, finding or building the probes? or do I salvage the parts and use my TTI one?

Has anyone worked with it? Is it any good?

Thanks in advance.

--Christoffer

[Lukas]

I've got one of it's bigger brothers the K450. It came with a huge "DOS option" comprising two 5.25" floppy drives. Supposedly, it's used to disassemblers for various processors of the time, pretty useless. It's got 48 data inputs which require a pod for a bus of 8. The pod contains some fancy thick-film circuits with bare dies bonded to the ceramic substrate. The pods get considerably warm. IIRC sample rate is in the order of 50MHz to 200MHz. The main unit consists of a card cage full of A4-sized PCBs packed with ECL gates and a humongous 500W power supply for all the ECL gates. Due do large inrush current the power supply made the circuit breaker trip several times. It also weighs >10kg and is as noisy as a vacuum cleaner.

Summary: unless you need many channels for some reason or are into debugging microprocessors from the 80s, logic analyzers from this time are pretty useless nowadays. A saleae logic (or one of its clones) is as large as a pod for one of these monsters and way more useful.

[ChristofferB]

or are into debugging microprocessors from the 80s

Almost all the electronics I do is design/restoration/modification of 70's and 80's microcomputers, so I do need a lot of channels!

 - The card size, weigh and ridiculously huge psu is recognizeable in mine too. If the pods (let's assume they're similar) is that sophisticated (in a 70's sense), it might not be worth it to keep it as a working unit unless one find the probes.

How does yours preform in use? Is it easy/comfortable to use (compared to other bench logic analyzers)?

--Christoffer

[Lukas]

You should have no problem replacing the probes with a bunch of medium-speed comparators with ECL outputs. That's my guess on what's inside of them.

The operation of mine is fairly simple (apart from the fairly advanced trigger), but kind of annoying as well. They arranged the hexadecimal keypad in a 4×4 layout with 1 2 3 4 in a row, you get the idea. So everytime I reach for the keypad I get confused.
The navigation in the waveform display is rather limited: Press one button to zoom in, another one to change the number of traces displayed. Panning is done by pressing the cursor keys for extended amounts of time. It's clearly missing a rotary encoder.

See https://www.mikrocontroller.net/topic/200148 for some 'screenshots' I captured by turning the ESC/P language the LA writes to its 25-pin RS232 interface at 1200baud into a bitmap.

I haven't used any other box-type LA than this one, so I can't say whether is one is particularly bad or just average.

[TAMHAN]

I am a gear head of course...but I would definitely keep it as a piece of history.

Re the non-vector CRT: please, don't bother with them anymore. If you build a gadget for yourself, ask Sir Won Hung Lo (aka AliExpress) for a nice cheap LCD and call it a party. At my exwifes agency, we phased out all CRTs in 2007 for eye pain reasons.

[ChristofferB]

Re the non-vector CRT: please, don't bother with them anymore. If you build a gadget for yourself, ask Sir Won Hung Lo (aka AliExpress) for a nice cheap LCD and call it a party. At my exwifes agency, we phased out all CRTs in 2007 for eye pain reasons.

It just wouldn't feel right, adding a modern LCD to a late 70's computer!

I might keep it as a historical item, and had it been a Hewlett Packard, I definitely would.
It just doesn't have a lot of history, the way I see it, it's not common enough to be classic, and not rare enough to be a curiosity.

--Christoffer