Repairing a $25K HP Workstation from 1981 to Run Pac-Man | Hacker News Reader

Repairing a $25K HP Workstation from 1981 to Run Pac-Man

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78 pointsredbell22 comments

Note the physical jog wheel in the upper left (which inspired https://news.ycombinator.com/item?id=35588770 )

HP used an RPG (rotary pulse generator) for the wheel. I believe they were the ones who invented it. It appeared it lots of their test equipment too.

https://picclick.com/Keysight-Agilent-HP-Avago-RPG-Rotary-Pu...

Is this a quadrature encoder or something more fancy?

I updated my comment above with a link. Just an ordinary quadrature encoder, but revolutionary back in the day.

Definitely not invented by HP though.

https://www.usdigital.com/blog/who-made-the-first-optical-en...

Okay perhaps not, but in my experience, HP was the first company to use them as a human interface device (HID).

Long before then I saw them on CNC gear that had nothing to do with HP.

What year? I first encountered one on a HP 8568 Spectrum Analyzer in 1978. They were also used on the HP 8672 synthesizer a year before that.

The company that made the ones I'm talking about is called Haidenhain and they were making these long before then. I think they go back as far as the 50's but I can't document that. But you'll find them all over old CNC gear.

Obviously the 50's was before the LED was invented. Did they use light bulbs? Also, they would also have had to use CdS photo-resistors instead of photo-transistors. Probably required a few vacuum tubes for the interface too. Seems like a lot of effort vs. a simple potentiometer.

I think that's particularly handy for interactively, remote controlling test&measurement gear. I want one!

Having recently had the (dis)pleasure of getting a DS1054Z oscilloscope, I'd confidently say I'd prefer mouse/keyboard-controlled numbers on a multi-gigahertz processor PC, over a waveform-scrolling jog wheel which updates at 3 frames per second with unpredictable acceleration. Though given a processor that isn't slower than trying to run YouTube on a Pentium M, I'd probably prefer a physical knob or dial for continuous parameter control.

Argh, I have the same 'scope and I know exactly what you're talking about. It's annoying to try to get the horizontal/vertical position over just enough without flinging it an entire screenful over. Not to mention trying to name files with the detent-less intensity/selection knob.

Great hardware for the money, but it sure is a little annoying to use. Don't forget to hack in the options if you haven't already!

I used to save files under the default name and rename on my PC, but got too lazy. I'm up to NewFile9.csv, having suffered from the scope refusing to recognize USB flash drives until I rebooted and lost my saved trace (DSRemote wouldn't connect to my scope over USB or Ethernet, I resorted to using the dreadful Windows UltraScope software to export a CSV) (somehow UltraScope manages to be as slow on a Ryzen 5600X as the DS1054Z software on the decade-old microcontroller), later stopped recognizing my drive mid-save (the progress bar hung indefinitely, the flash drive idle LED turned off) until I replugged the drive and tried saving again, and minutes-long CSV save times and randomly unchecking all but one save channel (I couldn't find good tools to parse .trc and .wfm files into PulseView-readable files).

So I'm not the only one! I thought the flash drive was buggy, but yeah my scope will just randomly start ignoring the flash drive I have in it. It's always after you capture that one-off random event and finally have it on-screen, too.

I haven't had the pleasure of using their desktop software yet. I do know that sigrok/pulseview has support for the DS-series, but aside from running it to make sure it could talk to the scope I haven't used it much. It doesn't look like it does much more than just duplicate the screen of the scope, but it might have more functionality that I am not aware of.

I had the pleasure of using a high-end but quite old digital scope recently (it had a 3.5 inch floppy drive for saving data). It's unreal how much nicer it was to use than much newer scopes (some of which were similarly expensive - the nicest one in the office has amazing specs but the interface is absolutely dire). I think it's just another example of the general trend towards lag in user interfaces.

I thought for a moment this was from Curious Marc[0], who has an addiction to vintage HP gear although mainly from the 60s and 70s.

I have no affiliation but if you like vintage computing he has quite an amazing video collection, including restoring and using gear from the Apollo mission.

[0] https://youtube.com/@CuriousMarc

This is most likely Tech Tangent. In the end hed details how the disk images messaged by the hp museum are hard to repro. Glad he deals with this, otherwise they could have been preserved but still lost.

It's not Tech Tangent I think. In the article he writes "some of the disk images [Tech Tangents] found at the HP Computer Museum" which implies to me that they're different people working on similar machines. Also Tech Tangent's name is Shelby, and this author is going by Robin Kearey, who seams to be a real person.

the article is about the Tech Tangent video, that is what I guessed and it is. the article writes about the dodgy video cable... which is shown in the first few minutes. so whoever wrote it, made a summary.

It plays pacman very shitty BTW, as the TSR control bar will stay on screen.

That monitor is gloriously minimalistic. What a great looking system!

With inflation that would be more than $83K today.

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