Notices by Tube❄️Time (tubetime@mastodon.social), page 2

i should boot an operating system, but i stole the SCSI2SD in this box for use with another system and i'm too lazy to find it. maybe the Amiga 1000?

now i can finally order my pizza.

bam! and it's in color now.

someone's got a clock generator

it's another early morning Silicon Valley Electronics Flea Market!

West Valley College. it's on Saturday again, but we have to share the parking lot with a farmers market now for some reason.

wire bonder

very old video switcher

macintoshes

new project drop: this is the design for my IBM Micro Channel DBA-ESDI drive emulator. super early alpha version!

https://github.com/schlae/difnif

found someone on the eevblog forums who said they reverse engineered a schematic. naturally, they never posted it and then fell off the face of the earth

doing a little digging with a sharp knife. you can see the anti-pad openings in the copper pour on the layer directly underneath. but there's no copper in the via barrel for me to solder to. it's all dissolved away.

drilled down until I found copper in the via barrel. I wonder if this will work.

this is why. there's one via that's broken. just one. that's the only thing standing in between me and a working card. I'll have to excavate to try and find some copper I can solder to.

the trace leading to it is cut so I can check for the ESD diode in the FPGA on the other side of the via to confirm when it's been reconnected.

so it passes all the tests except for the VRAM serial readout tests for one bank (bank 1, choices are bank 0-9). think I know why

(screenshot is from the self test for a different card but you get the idea)

still working on this. I've fixed a bunch of traces, let's see if it passes the self test

my hunch that i need the cables plugged in to pass the test might be right. looks like this card works now!!!

well, there's good news and bad news. my via fix actually worked! but now there's a problem with the comparators. :(

here's what i'm trying to do. the top image is a normal via. you can see this is an 8 layer board, and the via has no connections to inner layers. it just goes straight through. then in the middle image, the gunk has etched out the copper in the top part of the via. in the bottom image, i've drilled out the material to expose fresh copper, then jammed a wire in there. there's a little solder which (hopefully) wetted to the via barrel.

it was easier to just remove the resistor array completely so i could clean up the pads and the resistor leads.

yeah there are corroded solder joints on that resistor array. at least 1 high resistance connection.