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vintage computers, tubes, the MOnSter6502, cross-sectioned electronic parts, capacitors, and other detritus. coauthor of https://t.co/KTJOa1Kvu6
otaria123 Profile picture Ross Grayson, MPH, CIH Profile picture Glenn Profile picture fche Profile picture Steve Pick Profile picture 8 added to My Authors
Sep 26 33 tweets 11 min read
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.
Sep 21 23 tweets 6 min read
on the bench of healing: this IBM PC monitor. but it's a 5154 EGA monitor! let's dive in... Image the two Velcro tags on either side were probably for holding on a glare filter. Image
Sep 10 11 tweets 3 min read
an LED bulb in one of my fixtures started flickering a lot. let's tear it apart and see what's going on! Image it was really hard to pull the diffuser off. it was glued in! this part looks easier since there are just two screws. Image
Sep 4 6 tweets 2 min read
WHAT ? ALARM
Sep 2 49 tweets 12 min read
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...🧵 Image here is the mainframe without the packing material. it looks like 3 ISA cards!? Image
Aug 15 6 tweets 2 min read
dangit, my scope probe fell and smashed the plastic twist-on connector piece. let's try and fix it Image after an hour of CAD work Image
Aug 10 53 tweets 13 min read
here's a very odd-looking floppy drive. it's also quite special, so let's dig in! 🧵 Image when you put a disk in, this little lever pops out of the front. Image
Aug 8 25 tweets 7 min read
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. 🧵 Image here's a link to the auction itself, which has some better pictures.

rrauction.com/auctions/lot-d…
Jul 30 31 tweets 7 min read
something tragic happened to my Powerbook 145b, and i didn't even do anything to it! Image it's the LCD display. only two years ago it was in perfect condition. Image
Jul 20 165 tweets 38 min read
I got a new Mac! let's try to restore it and get it working. 🧵 Image two obvious problems: it's filthy and one of the keys is missing ImageImage
Jul 18 8 tweets 2 min read
here's something I picked up at Excess Solutions yesterday. some mystery wireless module. no screws but I think I can pry it open
Jul 14 8 tweets 2 min read
time to repair my little pet. a Commodore PET, that is. it hinges open, and there's even this little metal kickstand so you can prop it open like a car hood.
Jul 10 16 tweets 5 min read
did you ever hear about the serious nuclear radiation accident on Apollo 11? it's not what you think... 🧵 it had nothing to do with radiation in outer space, the solar wind, or anything like that; it was entirely caused by humans.
Jul 5 18 tweets 4 min read
my Amiga 500's floppy drive decided to stop working. Image i wired up a little breadboard circuit so i can force the motor to be selected constantly, allowing me to monitor the read signal and index signal with my oscilloscope. Image
Jul 2 8 tweets 1 min read
great thread. a good analogy to the bullwhip effect comes from control theory: too much gain in a closed-loop system leads to oscillation. big companies create ersatz planned economies which can avoid it, to some degree. what about a situation without a monopoly? something spread across lots and lots of really small companies? the "gain term" of the system is the mathematical limit of average human behavior. my guess is that it's still unstable.
Jul 2 22 tweets 5 min read
two years ago i promised to tell the Capacitor Plague story. that time has come! 🧵 (original thread)
Jul 1 20 tweets 6 min read
let's make our own electrolytic capacitor! 🧵 Image i'll cheat a little bit and start with...an electrolytic capacitor. we're going to take it apart! Image
Jun 28 15 tweets 5 min read
here's an interesting little hard drive (not working, of course) it's detected in the BIOS just fine. and it spins up...
Jun 26 6 tweets 2 min read
i randomly decided to revisit this project. while plugging the drive into a computer, i noticed this row of SIP sockets. could it be this simple? did i forget to terminate the SCSI bus? Image adding a SCSI2SD just for the termination, haha Image
Jun 20 13 tweets 3 min read
IBM always had the best keyboards, don't you think? the classic Model M, the iconic Model F... and ummm what in tarnation it's the infamous PCjr chiclet keyboard!
Jun 13 13 tweets 4 min read
i need to read these disks. yes, i have equipment that can capture the data at the flux transition level, but the equipment is not the problem. 🧵 this is the problem. i can't just pop the disk into a floppy drive like this.