here's a weird object! it's some kind of foot pedal with an IBM logo. is it for a sewing machine? electronic synthesizer? what do you think? 🧵 it's got a cursed connector! what IS that?

hey so remember the world's cutest oscilloscope i picked up last year? i think it's time to fix the probe socket issue.

https://twitter.com/TubeTimeUS/status/1513372232424501250

i printed a new panel insert that has two BNC sockets on it (the original probes would have had captive cables)

in honor of Sim Wong Hoo, here's a quick historical review of the Sound Blaster! 🧵 but first we have to go back to their first sound card, the Creative Music System from 1987. (image credit: Bratgoul on Wikipedia)

Tube Time: a 2022 retrospective 🧵
(and stuff you might have missed!) starting things off in january, i found a tube of super old 555 timer chips! i also decapped one of them.

https://twitter.com/TubeTimeUS/status/1481120280105811970

today's mini project: fixing this Radius Thunder IV GX daughtercard. it looks fine, but... 🧵 one of the chips has some broken pins!

on the bench of healing tonight: my coffee grinder which decided to bite the dust. symptoms: i push the start button and the motor just bumps a little bit and stops.

here is a really remarkable old chip. i decapped it today and was very surprised at what i found! 🧵 here it is, removed from the plastic carrier. based on the logo, this chip was made by Radiation, Inc. a very long time ago (maybe 1960s?)

here's a neat old graphics card! 🧵 it's the Multi Display Card from Paradise Systems, from around 1984.

I have a funny feeling I'm going to learn something interesting from this 9V battery... 🧵 huh, looks like it's an assembly of some sort!

new arrival at the Bench of Investigation: an Exatron Stringy Floppy drive! complete with a controller board!

even spicier tonight's mood is...🍃S P I N A C H 🍃

this is a very unusual printed circuit board! 🧵 instead of etched copper traces, tiny wires snake across the board, making all the connections. the wires are insulated, so they're allowed to cross!

say hi to the Pre-Modulation Processor (PMP) -- a critical piece of equipment in the command module of the Apollo spacecraft. 🧵 some of you may know that i've been working with @curious_marc and team on restoring and reverse engineering parts of the historic Apollo spacecraft.

on the bench of healing: this IBM PC monitor. but it's a 5154 EGA monitor! let's dive in... the two Velcro tags on either side were probably for holding on a glare filter.

an LED bulb in one of my fixtures started flickering a lot. let's tear it apart and see what's going on! it was really hard to pull the diffuser off. it was glued in! this part looks easier since there are just two screws.

WHAT ? ALARM

what's in this packing material? well, i purchased an IBM System 370 mainframe computer. but wait, you say! how can this fit on your workbench? glad you asked...🧵 here is the mainframe without the packing material. it looks like 3 ISA cards!?

dangit, my scope probe fell and smashed the plastic twist-on connector piece. let's try and fix it after an hour of CAD work

here's a very odd-looking floppy drive. it's also quite special, so let's dig in! 🧵 when you put a disk in, this little lever pops out of the front.

have any of you seen this rather stunning prototype of the Apple 1 computer which is up for auction right now? i have a few random thoughts about it. 🧵 here's a link to the auction itself, which has some better pictures.

rrauction.com/auctions/lot-d…

something tragic happened to my Powerbook 145b, and i didn't even do anything to it! it's the LCD display. only two years ago it was in perfect condition.