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1. Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 05:38:51 JST Foone🏳️‍⚧️

   Here's something cool I never realized existed:

   PCBs distributed through magazines!

   From Radio Electronics (June 1987):

   https://archive.org/details/radio_electronics_1987-06/page/n68/

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 05:43:45 JST Foone🏳️‍⚧️

     in reply to

     The way this works: You have a blank PCB coated in a thin copper layer, and it's coated in a photoresist material. This material breaks down when exposed to light.

     You then shine a bright (usually UV) light at it for a while, and the spots which got hit by light break down, while the other parts (which were in shadow) remain on the board.
     You then use a corrosive chemical to etch away the copper layer, but it only etches away the parts that aren't covered in photoresist.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 05:49:11 JST Foone🏳️‍⚧️

     in reply to

     So by using these magazine pages as your mask, you can create these PCBs with a chemical developing process and some blank copper-coated PCBs.

     That's really cool!

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 05:56:58 JST Foone🏳️‍⚧️

     in reply to

     Normally you'd do this by printing or photocopying onto transparent paper, but I think they're saying you can just turn up your brightness/wait longer and blast the light straight through the paper.

     I wonder how well that worked?

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:01:34 JST Foone🏳️‍⚧️

     in reply to

     And of course on one of the following pages, they had ads from companies who were happy to sell you the chemicals and equipment needed to make circuits this way.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:18:15 JST Foone🏳️‍⚧️

     in reply to

     The cool thing about this kind of photoresist PCB etching that may seem surprising if you know how circuit boards are designed today... you could totally do this without a computer.

     Fundamentally you just need to come up with a photomask: that's some dark black ink on a transparency. You could use stencils and stickers and markers to make that, then turn it into a PCB. The only electronics you need is a bright light.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:23:02 JST Foone🏳️‍⚧️

     in reply to

     it's just neat to think that today PCB design is "you use this complicated program on a computer then send some files to a place that mails you back a bunch of PCBs", when 30 years ago it would be more "you carefully do some arts & crafts with stickers and then some chemical processes"

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:26:50 JST Foone🏳️‍⚧️

     in reply to

     It's similar to how "amateur photography" went from "you have a dark room and a bunch of chemicals" to "you have a phone in your pocket"

   • vxo (vxo@digipres.club)'s status on Saturday, 18-May-2024 06:28:46 JST vxo

     in reply to

     @foone strange bubbling potion!!!

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:37:13 JST Foone🏳️‍⚧️

     in reply to

     • jornucopia

     @jordan I think that's a futurama joke.

     but yeah, I love the idea

   • jornucopia (jordan@sometimes.social)'s status on Saturday, 18-May-2024 06:37:14 JST jornucopia

     in reply to

     @foone full-size expansion card on a centerfold

   • vxo (vxo@digipres.club)'s status on Saturday, 18-May-2024 06:38:40 JST vxo

     in reply to

     @foone you have me tempted to merge graffiti art techniques into freehand PCB pieces, develop, then sneak in circuitry!

   • Drew Fitzpatrick (drewfitz@mastodon.social)'s status on Saturday, 18-May-2024 06:41:12 JST Drew Fitzpatrick

     in reply to

     @foone oooo did they have two side patterns or was that before the general use of double layer boards?

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:41:12 JST Foone🏳️‍⚧️

     in reply to

     • Drew Fitzpatrick

     @drewfitz yeah, this design here is a two-layer one!
     I'm not sure how you do that. I guess you just expose it twice, once on each side, and then do the etch step once?

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 06:49:13 JST Foone🏳️‍⚧️

     in reply to

     • Hugo Mills

     @darkling yeah the vias are real tiny, so you need a fast drill with a very tiny bit, so it's a little tricky to do by hand.

   • Hugo Mills (darkling@mstdn.social)'s status on Saturday, 18-May-2024 06:49:15 JST Hugo Mills

     in reply to

     @foone He also had problems with drilling the holes in the board, so he was building an X-Y rig for a drill.

     We spent a long night with an Acorn A440, me on the front end with the keyboard, him on the back end with the printer port and an oscilloscope, working out how to write a driver for this thing that ran off the !Draw files he'd use for the board designs, and would put the holes in the right place.

   • Hugo Mills (darkling@mstdn.social)'s status on Saturday, 18-May-2024 06:49:16 JST Hugo Mills

     in reply to

     @foone I think I met something like this back in 1989 or 1990. A friend's dad was doing this with his own designs. He found that photocopies or laser prints on acetate weren't dense enough to block the UV properly, so you had to run it through the printer several times to get the ink density to make it work.

   • Jencen (jencen@furry.engineer)'s status on Saturday, 18-May-2024 07:14:03 JST Jencen

     in reply to

     @foone Huh.... I wonder if that'd work with the PCB layouts that are in older service manuals from places like Yamaha or Roland >.>

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 07:14:03 JST Foone🏳️‍⚧️

     in reply to

     • Jencen

     @Jencen certainly. Especially if you scan them, clean them up a bit, and print them out onto transparent sheets

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 07:35:36 JST Foone🏳️‍⚧️

     in reply to

     • Xe :verified:

     @cadey you have big pockets

   • Xe :verified: (cadey@pony.social)'s status on Saturday, 18-May-2024 07:35:37 JST Xe :verified:

     in reply to

     @foone what would you call this

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 08:01:04 JST Foone🏳️‍⚧️

     in reply to

     • vxo

     @vxo Did you ever see my Copy Pro Control board? I still made it in Kicad so I couldn't get to weird with it, but I did attempt to get as Weird as possible given the circumstances.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 18-May-2024 08:13:04 JST Foone🏳️‍⚧️

     in reply to

     • Graham Sutherland / Polynomial
     • F4GRX Sébastien
     • ĸurth

     @kurth @f4grx @gsuberland these look tasty. some kind of fried chicken!

   • ĸurth (kurth@social.tchncs.de)'s status on Saturday, 18-May-2024 08:13:05 JST ĸurth

     in reply to

     • Graham Sutherland / Polynomial
     • F4GRX Sébastien

     @f4grx @gsuberland @foone

     yeah, remember those dirty balls

   • F4GRX Sébastien (f4grx@chaos.social)'s status on Saturday, 18-May-2024 08:13:06 JST F4GRX Sébastien

     in reply to

     • Graham Sutherland / Polynomial

     @gsuberland @foone ferric perchloride is so old school and annoying. copper chloride is the way to go. in practice that just means hcl with a pinch of h2o2. when depleted it can be replenished with an air bubbler.

   • Graham Sutherland / Polynomial (gsuberland@chaos.social)'s status on Saturday, 18-May-2024 08:13:07 JST Graham Sutherland / Polynomial

     in reply to

     @foone iirc one of the tricks was to add some sort of clear oil (like baby oil) to stick it to the PCB, which made the white paper go kinda clear.

     the actual home etching process is super messy though. ferric chloride stains eeeeeverything, it's bad for your skin, and you have to neutralise it before disposal which also creates a lot of mess. I used to own a kit and used it only a couple of times because the cleanup is horrible.

   • vxo (vxo@digipres.club)'s status on Sunday, 19-May-2024 10:11:39 JST vxo

     in reply to

     @foone I love it!!

   • Tim 🎮 (timixretroplays@digipres.club)'s status on Sunday, 19-May-2024 12:49:08 JST Tim 🎮

     in reply to

     • vxo

     @foone @vxo best easter egg hunt