today's hike. went up a mountain, saw an antenna.

i fixed a computer this week. this is the 1960s IBM 1401 at the Computer History Museum in California.

Happy birthday to the MOS 6502! It was 50 years ago today that people were able to buy their first samples of the chip from a jar in a hotel room at WESCON. Here's my oldest 6502 from the 52nd week of 1975. Still works perfectly!

be sure to check out this Humble Bundle which includes my book, Open Circuits, along with other great titles! (Game Console is one of my faves.)

caption this

Celebrated Navajo (Diné) artist Marilou Schultz recently completed a striking weaving. Although this rug may appear abstract, it is a representation of the wiring inside an integrated circuit. It shows the 555 timer, said at one point to be the world's most popular IC. Let's take a closer look...

Me being told by the developer that no, they will not accept my 60's blueprints, $75000 for an 8000 square foot plot is barely a tenth the value of the land and to leave the site immediately because I'm trespassing. (2025)

so Microsoft open-sourced their 6502 BASIC interpreter. i'm reading through the code looking for interesting things, and i've already found a few! 🧵 github.com/microsoft/BA...

This is pretty cool. The source code for Microsoft BASIC for 6502 (Apple II, Commodore PET, etc) from 1978, released under the MIT license. opensource.microsoft.com/blog/2025/09...

ever wonder what happens to batteries after they die?

i reverse-engineered the Raspberry Pi Compute Module 5! check it out at github.com/schlae/cm5-r...

going to stream some reverse engineering work in a few minutes! check out www.twitch.tv/tubetimeus

Weavings by Marilou Schulz (Diné) on view in “Once within a Time” at SITE Santa Fe.

How did Intel's 386 processor connect to the outside world? Tiny wires connect to the bond pads around the edges. Special input/output circuits—visible in zoomed-in blocks—send and receive signals while protecting the chip from dangers that could destroy it. Let's take a look... 1/N

retrocomputing...in 1976!?

this DIP chip has a tiny window in it so you can see the quartz crystal inside. (it's a PXO-600 programmable crystal oscillator chip)

today i learned that you can use a VNA to measure ferrite beads. so i made this little 3d-printed jig for the tiny surface mount ones!

from yesterday's hike. anyone got a bicycle pump?

Intel's 386 processor was popular in late 1980s microcomputers. From the outside, the 386 chip is a boring ceramic square. But I obtained a 3-dimensional CT X-ray scan from Lumafield, revealing six layers of complex wiring hidden inside the ceramic package. Let's take a closer look... 1/N

This explains a lot about some of the model railroaders I know.

i'm proud to have been involved in the creation of this new book from @nostarchpress.bsky.social, Designing Electronics That Work! it's full of useful material for anyone who wants to build anything electronic and bring it to mass production. nostarch.com/designingele...

i've added support for more RAM chips to the Pico DRAM Tester! 4027 (4K x 1) 4108 (8K x 1 that are 4116s with only half test good: MK4108, TMS4108, etc) 4132 (32K x 1 that are 4164s with only half tested good: TMS4532, M3732) there are also bug fixes. github.com/schlae/pico-...

EXCLUSIVE: here are the plans for the Lunar Nuclear Reactor!

Big congrats to the System Source museum for winning the Halt and Catch Fire award today!

are you in Silicon Valley? do you want to check out some old computers tomorrow and Saturday? Come by the Computer History Museum for the Vintage Computer Festival. i have an exhibit there as well, come by and say hi! connect.computerhistory.org/events/1ffce...

here's my latest acquisition! it's a manual key punch. i'll be using it to write poetry for the 1960's IBM 1401 computer. did i say poetry? i meant "single card programs"

The new RP2350 A4 version fixes the GPIO current sourcing bug AND they've listened to us and the device is now officially 5V tolerant! fantastic!

a flower? no, this is a transistor (CDQ19136, Teledyne, 1973)

I really do see more people's posts under the discover tab than I do the following tab Under the following one it's just the same dozen or so people over and over plus my own posts

just keep blaming it on lag

just keep blaming it on lag

ahh good old DOS error messages.

It’s the 40th birthday of the first computer I remember using. The Amiga 1000 was released this day in 1985!

so um I've owned this Hakko FR-301 desoldering gun for years now and I just discovered that the blue handled "screwdriver" is actually meant to clean out the heater. 😳

We obtained a mysterious box of 1960s electronics. I reverse-engineered it, and with much effort, we got it running. It turns out to be a test unit for testing NASA's Up-Data Link, a system from the Apollo moon landing to control the spacecraft from the ground. Let's take a look inside... 1/n

We're at OpenSauce 2025, showing off Apollo hardware, electromechanical computers, the MOnSter 6502, and other treats. Join me, @tubetime.bsky.social, and Mike at the CuriousMarc booth!

Check out FOSSF Silicon at Open Sauce this weekend! We're showing off the FOSS semiconductor design + fabrication ecosystem including a Hacker Fab stepper, tube furnace, Maasi spin coater, prototype devices, and much more! Booth C.18

come see me at Open Sauce this weekend in San Mateo! i will have the MOnSter 6502 on display! this is the world's largest 6502 microprocessor, built out of discrete transistors. it will be set up at CuriousMarc's booth.

Ugh! eBay sellers strike again. It's not ok to pack vintage hardware in grocery bags. Parts were missing because the box was busted open. 3D print parts, trim to fit, sand and color match. Not perfect, but better than a giant hole.

I'll be at OpenSauce 2025 along with @curiousmarc.bsky.social, @tubetime.bsky.social, and Mike. We plan to show some Apollo hardware, atomic clocks, vintage avionics, and who knows what else, so stop by if you're attending. opensauce.com

These right-angle SMD adapters go kinda hard. Makes sense if you want to have a hall effect sensor at the right orientation.

It's Soup Tube Time

sad that the subminiature AC power plug never took off. the design was inherently safe since kids couldn't fit forks or scissors in

The Globus is a navigational instrument that uses a rotating globe to show the position of the Soyuz spacecraft above the Earth. Inside the Globus, a complicated system of gears and motors positions the globe. @jonbruner.bsky.social at Lumafield created a three-dimensional X-ray scan for us. 1/4

Apple’s Liquid Glass is coming along!

Hahahaha, thanks?

how about one of the first few hundred computer hard drive read/write heads ever made? this prototype head was made for the IBM RAMAC.

San Francisco is the city in which Farnsworth invented the image dissector tube and made the first all-electronic television transmissions, and yet despite this, his workshop at 202 Green is just some office building, and not an impressive museum to the history of television

someone reminded me that tomorrow is also this station's 100 year anniversary!

incredibly, there is still an *operational* Alexanderson transmitter! it is called SAQ Grimeton and they fire it up twice a year. in fact, if you want to listen to it yourself, they're going to operate it TOMORROW!