Tube❄Time

rainwater collection system?

book excerpt. "...ASCII, pronounced 'ass-key'."

I mean can you figure out a better way to help people pronounce ASCII?

What if the Apple ][ had run on Field-Sequential? One thing I remain fascinated by is the field-sequential color system. Essentially, unlike composite video, which sacrifices color depth in space, field sequ...

New blog post! A what-if scenario where we try to see how a home computer designer might've dealt with the field-sequential color television, had the Korean War not stopped that standards' rollout. Enjoy! nicole.express/2026/the-app...

fun fact--the Apollo moon mission's color cameras were field sequential, essentially System 1 in your table. this caused weird color artifacts when transmitting the LM's launch from the surface.

super clean looking, wow

yes. pretty nuts, right?

they call it pop art, but a can of Campbells is not a can of Coke.

screenshot from the failed Magic Cap operating system. hallway with a door, a table, and some signs on the wall. there are a row of buttons at the bottom.

i mean it has that Magic Cap energy

still in progress, slowly

a "pixel art" room with a sofa, telephone on a small table, a door, window, and some artwork on the wall, including a Lichtenstein painting titled "Look Mickey"

a bad Leisure Suit Larry game? no, it's Roy Lichtenstein in 1973.

there's also this, lol. www.vogons.org/viewtopic.ph...

MM1025 PDF Part #: MM1025. Description: System Reset (with battery back-up) Monolithic IC. File Size: 63.95 Kbytes. Manufacturer: Mitsumi Electronics, Corp..

Mitsumi MM1025A system reset IC.
www.alldatasheet.com/datasheet-pd...

i saw those earlier!

metal can oscillator marked HOORAY VX8111 34.500MHz . 9 1 4 1

Hooray! it's 34.5MHz!

peeling pcb layers with a spudger

sanded the copper off the top so the via barrels had no tops.

the board i sacrificed for this had extensive rot from the adhesive. it made it all the way through to the other side of the board through a via.

which ones do you have?

it was actually easier to peel the layers apart.

yeah that's a weird one. think they're trying to add a series impedance to a filter capacitor.

electricity is one of the few commodities that costs more to make more of. it's the opposite of a quantity discount.

3 months

Tube❄Time (@tubetime@mastodon.social) Attached: 1 image oh now that's some corrosion. (hp 16717a logic analyzer card with the characteristic corrosion caused by the decaying adhesive foam holding the plastic guard slides in place)

full thread with all the details is over at Mastodon: mastodon.social/@tubetime/11...

top level schematic of a complex circuit board.

what's really useful is that i now have the complete schematic, which i used earlier today to repair one of these cards that was broken. and best of all, i've released it so anyone else can see it: github.com/schlae/hp16717. so if you have an obscure HP logic analyzer, check it out!

xacto knife on top of a board with some of the copper layer removed. on the right is a small pile of copper shavings.

and yes, it was a bit tedious.

circuit board, backlit, with black traces highlighted against a glowing light brown fiberglass substrate.

the middle two layers look very cool since light can easily shine through.

center "core" layers of the board with a bag of parts on top and a bag of copper fragments. there are rolled up sheets of FR4 fiberglass that look like scrolls.

i scanned the board one layer at a time, peeling away layers of copper and fiberglass to expose the layers underneath. almost 3GB of image data.

colorful circuit board in a layout program. each layer is a different color. it's complicated!

this is the largest circuit board i've ever completely reverse engineered. 8 layers, larger than a sheet of paper, 1000s of nets, over 1000 parts. 🧵

I found the old 35mm slide for the cover for Neuromancer and had it scanned in for your pleasure. Enjoy!

clever trick. you could do something similar with one of those digital output hall effect sensor chips. might even respond faster

New blog post: Remote diagnosing a PET 2001 video fault from one photograph.
blog.tynemouthsoftware.co.uk/2026/02/diag...
Includes a look at how the PET video system works with redrawn schematics.
It also turns out to be a surprisingly early PET 2001.