Atkelar Cat
@atkelar
Coffee addicted cat who loves to tinker with old school tech stuff... also makes videos of the process! - bsky account is a test run for now... See for the videos!
VT-110 Progress... But I am still not quite happy with it... see how the bars are "fading"? They should be solid. Something is still off in the chain.
And the Furries at #viennacomix are having fun on day 2 too! (Higher res pics to come after processing!)
Hmm... it worked here - not that I could not copy my four members manually - but it seemed to have requried a double click... the first click didn't do anything here either.
My universal ROM cartridge for the HP 9825A is done! Yay! The next update video will have details on the "oopsies" I had with it. But it does work!
Oops - forgot to hit "Post"; a bit late here... "I can see my house! Zoom and enhance!"
I think, I got all the mechanical parts connected again... at least all of them for the tape transport. Some other bits are still to do; I'm trying to make a quick short, showing off the movement of levers in the different functions, but that needs a working motor driver and power supply.
Does anybody here have an idea what these breadboard style sockets might be called? Or where I could get a bunch? These are used on several PCBs around prototyping kits I have, and I have a project in the queue that might benefit from these...
Day 23 - And a view of the 9825A motherboard. We have the CPU under the heat sink, expansion bus in the rear and memory bus to the lower left. The top left is unused in the "A" model, up front is the power connector. #TWAAC
Day 22 - Ah! I love these ceramic chips! In this case, it's a carrier for several pieces of silicone inside. The metal cover is glued on, so no peeking, but for a 1978 chip design, it is radical! HP 9825A CPU! #TWAAC
Day 21 - I don't think I have shown the populated logic troubleshooting kit from HP? I got the box with the logic comparator and added the probes which came with other "lots" for completeness. #TWAAC
Day 20 - This is the chip set for the Sanyo calculator; Again, white ceramic chips! I got quite a few of these this year! #TWAAC
Day 18 - Something scary for today: this is how a calculator from the 1970s looks like when a NiCd battery oozes all over. If you store devices: take out the batteries!! Sadly, this one is not salvageable. The LEDs in the display have turned into dust. #TWAAC
Day 17 - And a tiny little CRT! Black and white, but still: one of the tiniest CRTs I've seen, at least with magnetic deflection! #TWAAC
Day 15 - And here we have the lit up version of the LED matrix display! They don't make things as beautiful as this anymore... #TWAAC
Day 14 - I was on vacation in Germany... my hotel room had bolts in the wall! I was tempted...! #TWAAC
Day 13 - The insides of the Heathkit IT-1202 Nixie meter, pre-cleanup. #TWAAC
Day 12 - Yes! That is more like it and looks like the expected schottky diode. Reversed anyhow. The original one was a flat line. Literally. #TWAAC
Day 11 - And another ceramic IC; this one is quite the beast. Not so much for density or functoinality, but it might be considered one of the first ASICs out there. It has a bit of ROM, and quite a bit of glue logic inside; The 9825 KDP! #TWAAC
Day 10 - Cross view of the main PCB in the HPIB analyzer. I love how neat the traces are. #TWAAC
Day 9 - Another breadboard prototyping thing! This time, built into a sturdy metal suitcase. I converted it to my standard magnet strip style, so it takes my metal-backed breadboards. #TWAAC
Day 8 - Bare metal debugging! What you see is a bit of a trace on the data and address bus of an old computer system. Looking up the numbers in the instruction set and checking against the expected source code... #TWAAC
Day 7 - Hmmm... the question is: is this a 7448 chip from week 47 in '74... or is it a 7447 chip from week 48 in '74? Funny coincidence, and I almost sent the chip back for being the wrong one... #TWAAC
Day 6 - Sometimes botches take weird forms... I needed to pressurize the water tank for my water supply. After rummaging through my leftover fittings box, I say: good enough! #TWAAC
Day 5 - Another calculator project that is waiting its turn! Nothing too special on the technical side about this one, but certainly a piece of history! #TWAAC
Day 4 - And digital troubleshooting on a revision 1 PCB. From my paddle game project: trying out a fix for a problem before ordering the re-made part! #TWAAC
Nixies! Some awesome calculator action here! This is the Sanyo caluclator, with the rightmost digit still bleeding into the leftmost during rollover, because there is a flaky short in it somewhere. #TWAAC