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Since it’s hard to search Twitter, I’ve put together a compilation of some of my best Twitter threads.

Welcome thread #1
Welcome thread #2
Micropodcast Episode 1

Cross Sections

Dipped tantalum capacitor (my first cross section)
LMR-195 cable
Fiber optic cable
Undersea cable
Ethernet plug and jack
VGA cable
Type N connector
Type N connector (annotated)
Apple Magsafe connector
DVI single-link cable
Tantalum capacitor from Fluke 8400
BNC plug and jack
Flat phone cable
RIFA paper capacitor
SFP DAC cable
BGA package
USB-C connector
AC power cable
MAX233 chip
Another USB-C cable
Micro SD card
Magsafe 2 connector
DIP socket
Glass thermistor
DIP socket (machine pin)
Carbon composition resistor
Blown LED
Micro-D connector
Modern BGA SoC
MacBook power cable
HDBNC connector
Axial aluminum electrolytic capacitor
12AX7 vacuum tube
Slowly rotating and dramatically lit cutaway view of a 12AX7
12AX7 vacuum tube (behind the scenes)
2N2222 in a TO-18 metal can
Bi-color red/green LED
2N3904 transistor (TO-92)
1N914 diode
DE-9 plug and socket
Headphone plug and jack
Electrolytic capacitor
15-turn potentiometer
Audio transformer
BGA chip
Quartz crystal (HC-49)
Electret microphone element
LR44 alkaline button cell
Vibrator motor
DIP switch
Film capacitor
Tact switch
Magnetic speaker
Slide switch
Ceramic chip capacitor
Reed relay
Polymer electrolytic capacitor
SMA connector
Ethernet transformer
Prototype XL741 Kit
Fencing scoring machine


Zenith Minisport
HP125 keyboard reverse engineering
1982 DisplayPhone video call
Northern Telecom NT6K00AN DisplayPhone from 1982
MOS 6581 sound chip — aka the Commodore SID chip — slowly rotating and dramatically lit
slowly-rotating, dramatically lit Yamaha YM3812 OPL2 synthesizer chip
The KIM-1 lives!
Just wrote my first blink-an-LED program for this microcontroller, which is quite special…
Today i dug up my first mobile computing device. i bought this over 20 years ago. i wonder if it still works…
Two identical-looking Commodore mouses aren’t compatible. Why?
Epson HX-20 repair
Epson HX-20 thread
New Apple laptop this weekend. New to me anyway.
Fischertechnik robotics kit.
Prototype Connor IDE hard drive.
Atari 800 connected to modern PC
Rockwell AIM-65 computer with the MOnSter 6502!
GEOS on the C64.
Rebuilding a C64 power supply.
UNIX computer that uses audio cassettes for storage.
The Xerox Notetaker from 1978, the first computer to ever be used by a passenger on a commercial flight.
Say hello to the Intel SDK-86, the first computer to use the 8086 microprocessor!
AIM65 keyboard repair
Unusual keyboard keyswitch
There’s nothing quite like the ear piercing screech of a dot matrix printer generating a line full of ‘#’ symbols.
AIM-65 says hi
Cursed 3mm audio plug. Yes, it’s an Apple product.


35 years ago today, the Amiga 1000 was born!
Amiga 1000 secret RAM
Resurrection of an Amiga 2000 motherboard.
Commodore CDTV
Amiga 1200 RAM expansion
Swapping out 200-pin Amiga CPU connectors
New Amiga 3000
SOIC pin repair.
Amiga 4000 with Toaster Flyer
GVP RAM for Amiga 2000
Experiments with Toaster Flyer 4000
Amiga ROM adapters for 27C4096 EPROMs to 27C400-style ROM pinouts
Amiga 1000 ROM easter egg
Amiga 500 with a PC hidden inside
Extreme Amiga 4000 repair
Amiga Brataccas with unusual copy protected disk
Amiga ticking floppy drives


IBM PS/2 Model 95 computer experiments
IBM 7496 executive workstation video review
PCI versus microchannel slot
PS/2 floppy adapter thread
Installing OS/2 2.1 on the PS/2 model 50Z
OS/2 2.1 thread
Replacement plastic fasteners for IBM PS/2 systems
Field stripping my PS/2 Model 50Z
PS/2 model 50Z drive sled (3D print)
MCA bus experiments
Expanded memory card experiments


ISA bus IO_READY signal
Exploring the light pen
Experiments with 90MB Iomega Bernoulli cartridges
Rev A IBM 5150
Presenting a Targa video card from the mid 1980s
Experiments with the Targa 16 video card
Three monitors on an ISA bus computer
Graphics demos for the IBM EGA
Number Nine Revolution 512×8 graphics card from 1984. It was one of the first hardware accelerated cards available for the IBM PC!
Windows 95 UI book is *glorious*
Iomega’s Bernoulli box of 1982 was *not* the first floppy disk to use the Bernoulli principle.
Imaging Bernoulli cartridges.
The official IBM game control adapter has several unusual features.
Extreme 486 motherboard hacking.
Early MDA graphics cards could actually do color!
The original IBM PC had a cassette port
Found something strange on an 8″ floppy disk.
Metheus Ultra Graphics Accelerator 1104 has only two video modes: 1024×768 and emulated CGA at 960×600!
Extreme Sound Blaster 16 repair.
Unusual Okidata gm3315b 5 1/4″ floppy drive. It’s thin!

Homebrew Hardware

The Intersil IM6100 is a PDP-8 on a CMOS chip! What should I do with it?
Scopetrex build thread
Announcing the SCOPETREX — the vector gaming console for your oscilloscope or XY monitor!
Plaid Bib build thread
Plaid Bib announcement
Plaid Bib CPLD announcement
Snark Barker MCA engineering thread
Roland MPU-IMC card
Open-source clone of the IBM extender and receiver cards for the IBM 5161 expansion chassis!
IBM extender board thread
Announcing the Snark Barker MCA!
Wanted: your *broken* old Sound Blaster 1.0, 1.5, or 2.0 cards. That DSP needs to get dumped!
Snark Barker build thread
Clones of my Snark Barker SB 1.0 clone are apparently now available in Hong Kong.
A CDP1802 breadboard computer that starts simple and gets complicated
I made a controller for my Vectrex clone today!
Own an IBM PS/2 model 50, 50Z, or 70 with a broken proprietary floppy drive? Here’s a way you can make your own replacement out of some 3D printed parts and a standard PC floppy drive!

MOnSter 6502

MOnSter 6502
MOnSter 6502 running validation program.

Tube Stuff

Fixing my Fluke 8400A digital voltmeter.
A look at my private stash of Nixie tubes!
One of the first digital voltmeters, the Fairchild 7100.
The bad tantalum cap in my frequency counter that started the cross section project
Power your Nixie tube with a coin cell!
One of my Nixie clocks that I built almost 13 years ago.
One of the world’s first electronic calculators, the Friden EC-130.
Testing vacuum tubes
Some unusual vacuum tubes
Using a VFD display as a triode
In 1959, GE tried to convince the world that vacuum tubes were better than transistors.
Oh look, it’s a vacuum tube module from a 1950’s IBM computer!
It’s tube time! well, time to sort and test some vacuum tubes.
A 120 year-old light bulb!
The Sony Watchman has a very weird “flat” CRT
Fired up my Sony Watchman today, and I actually found an analog TV broadcast
Check out this neat CRT display!
Playing with CRTs today. I can almost hear the sound effect this visualization pairs up with.
3D vector clock with three CRTs
A CRT with P7 long persistence blue/yellow phosphor
My friend’s TV pattern generator uses a tube called a Monoscope
First image from the Raytheon CK1414F10C Symbolray character generating tube.
Got a package dated June 28th, 1944.
Tidying up this tabletop Battlezone arcade machine I built
This cool 7-segment display uses neon instead of LEDs
Check out the archives of the Journal of the Society for Information Display.
Imagine it is 1935, and you’re trying to troubleshoot a circuit. How would you look at a voltage waveform?
Come to California Extreme! Come play my vector tabletop arcade games!
Don’t have a proper vacuum tube socket for a 7 or 8 pin miniature tube? Tear apart a solder cup DE-9 socket!
This is weird, someone is still broadcasting in UHF!
Do you remember that high-pitched whining sound that old school tube TVs used to make?
Let’s take apart this old TV camera!


This is the 26 x 72 foot (8 x 22m) crater resulting from the gas pipeline explosion in San Bruno in 2010.
This Tesla SUV ran into a traffic barrier at 70mph while on Autopilot. How could this happen?
This electrical transmission tower has a little problem. Can you spot it?
A tiny company nobody had heard of, Cadtrak, sued Commodore for patent infringement and won
All right, this is a new one. A EULA on…fruit?!
This happened to a Boeing 787 while it was parked at Boston Logan back in 2013
Celebrate Beethoven’s birthday by listening to this *remarkable* recording from 1944

Electronics Learnings

Why does the schematic symbol of a bipolar transistor look the way it does?
Performing computations with DRAM
Some neat IC die photos
A very clever radio transmitter circuit
Investigating a tunnel diode
I once made a transistor out of a germanium diode and a guitar string
When the first IC chips came out, General Electric fired back, introducing the Compactron in 1961.
How did people simulate heat transfer, fluid flow, and electric fields before we had fast computers?
Repairing a vintage analog oscilloscope
Weird diodes
Wanna see an old telephone stepping relay in action?
Troubleshooting the pulse dialer on my Automatic Electric type 80.
Fixing my other logic analyzer, the HP1661A.
An incredibly rare transparent SOIC chip package.
Let’s talk about multipliers!
Here’s the Intel 1702, the first erasable, programmable read-only memory (EPROM) from 1971.
You’ve never seen this D-sub connector before!
D-sub connectors were invented in 1952 at Cannon by Sam Arson!
This neon lamp should never light up!
Parts inside parts
Here is part of the payload electronics from the Explorer 8 satellite (1960)!
I went to the first Bay Area Maker Faire back in 2006. Here are some of the photos
Today i finished building an AM radio for the @hackadayio circuit sculpture contest.
I decapped this LH0070 precision 10V reference, and found something unbelievable inside.
Some IC chips come in clear plastic. I picked up a tube today.
Let’s look at old school LED displays under a microscope.
Troubleshooting the STM32F407 USB bootloader
Let’s take apart this old chart recorder!
This is the uA702, the first commercial analog chip (an op-amp).
Here’s a fun little mystery! See this 2N2222A transistor…
Here’s an interesting part, the LM399H voltage reference.
This desk fan is 85 years old and still running strong. How would YOU design an electronics gadget to last 100 years?
Hey look it’s an ultra-rare transparent IC chip!
TIL about stakeless earth ground measurement.
It’s not always a software problem. It’s not always a hardware design problem.
Measuring propagation delays through buffers from different logic families.
Fixing a 1960s Japanese transistor radio.
Here’s a fun little cascaded Peltier cooler. Let’s see how cold it gets!
Time to visit the giant 2N696 in person!
You may have heard of an IC named after someone, but have you ever heard of a chip *pin* named after a dog?
Let’s read this @digikey catalog from 1987!
Illegal RC car!
Check out this cool prototype LED!
Discrete breadboard version of 555 timer
Around 1994 I built this voice recorder box with my grandfather. I wonder if it still works…
This is an EMP-20 device programmer from the early ’90s. it supports a huge variety of devices. The thing in the side that looks like a SIMM socket? It’s not…
Surprising facts about electrolytic capacitors
Altered chips
The first commercial product I ever designed
Here’s a nuclear battery in a DIP package.
PSA – Don’t store your chips in that black ESD foam!
Built a phono preamp
Why are chips often so expensive?

Reverse Engineering

Reverse engineering the IR3E02 chip “DMG-REG” from several Game Boy variants.
Here’s the Snappy Video Snapshot. It is a video digitizer.
This computer has a really neat VGA BIOS screen with a shimmering rainbow
This is an LM168 voltage reference.
Time to extract some bits from this ROM image.
This is the chip layout of the famed Intel 80C51 showing all of the basic functional blocks.
Today I confirmed that I have a bit-accurate dump of the Sound Blaster CT-1351V202 DSP 2.02 firmware!

Flea Market Threads

Sep 14, 2019
Aug 10, 2019
Jul 13, 2019
Jun 8, 2019
May 11, 2019
Apr 13, 2019
Mar 9, 2019
Sep 8, 2018
July 14, 2018
Apr 14, 2018


An off-brand capacitor failed on me, so I made a TV commercial
Here’s the new proposed USB-C connector.
I didn’t have a terminator for a 1/4″ audio jack, so I had to improvise…
Salesman: *slaps roof of 7805* this bad boy can fit so much magic smoke in it
What kind of sadist makes a breadboard that is 3 rows too short to fit a 40-pin DIP?
Since everyone’s reviewing emojis, let’s look at the light bulb emoji.
Aren’t D-sub connectors neat? Here is a DA-15 (bottom) along with a… hmm… hipster D-sub.
Saw the Jameco truck at Excess Solutions today.
Let’s order strange things from NIST! First up is this jar of reference peanut butter.
7 segment LED? Nixie tube?


Prototype 4″ floppy disk drive
Prototype BART ticket card with magnetic stripe
World’s first hard disk head
First prototype of the Hercules graphics card
I see your bit and byte, and I raise you a prototype head for the world’s first hard drive, the RAMAC.
This is a module from the IBM 4 Pi series aerospace computer. Not bad for 1972!
Here’s the wire-wrapped prototype of the original IBM PC (5150) motherboard!


The WeirdStuff sign has turned off for the last time. 🙁
WeirdStuff megathread: What’s your best memory of the place?
Vintage laptops at WeirdStuff!
Super clean IBM PC convertible at WeirdStuff
Yep, HSC is closing.
HSC electronics is up for sale.
HSC electronics sure was expensive back in the day.
The photo is HSC Electronics (their old building). The coffee machine was just to the left out of the frame.
HSC electronics has been sold to Excess Solutions!
HSC/Halted electronics featured in Newsweek, March 21, 1983
HSC Electronics sale today!
Last day for Halted
It looks like Amazon is buying a bunch of buildings, including the one occupied by Excess Solutions
At Excess solutions. Check out this wave solder machine!
My visit to Excess Solutions.

3d printing

The orientation makes a difference when 3D printing something!
2020 Retrospective Thread

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