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Lear Siegler ADM 3A Terminal - Raspberry PI

taos23

Member
Joined
May 7, 2019
Messages
44
Location
Austin TX
Lear Siegler ADM 3A modernized and connected to Raspberry PI via RS-232

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What's done to it:
-Disassembled, thoroughly cleaned
-Painted top bright white (bottom remains dark brown)
-Removed all keys and retro whited them to get brighter letters
-Covered dip switch plate with white printed decal
-Added switch to the motherboard to eliminate column 72 beep
-Added lower case rom (from another motherboard).

Here's before photo, and new pictures of the keyboard

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Cool. Mine is blue. A few of the keys are sticky, it doesn't have lower case, and I'm missing the cover for the option DIP switches that you have. I need to get me one of those. The display on mine is perfect and white phosphor.

It was gifted to me by one of my former co-workers who assembled the kit himself back in the day!
 
Hey thanks for the kind words everybody! Absolutely my favorite "vintage device" at the moment. There's a lot you can do with PI/debian and scripts, even at 9600 baud. I ended up buying two of them, one for parts to get the lowercase ROM. It's was an option for the 3A back in the day, and I'd say 50% or less had it. Really easy to install, 2 RAM chips, 1 ROM chips, and set a dip switch. There's a great document online about how to identify lower case ROM and install it:https://www.esocop.org/docs/LearSeieglerLowerCaseOption.pdf
 
This is exactly what I want to do if I can get my hands on one. It’s one of the only things I want from the vintage computer space. Let me know if you ever decide to sell.
 
I have two ADM3a's, one is beige with a brown base and one has a blue top. I put in new CRT's (old-timey blue-white, not the later paper white available in the late 80's+ color). I've been paranoid about burning those screens and on my to do list is a hardware screen saver for them.

One of mine had the 2513-L, and I made a 2716 copy and an adapter for the other one. This page ( http://www.juliepalooza.com/sl/adm3a-2.htm ) describes it and contains a downloadable 2716 image of the 2513-L. I worried about copyrights until I realized that there are darned few ways to make a font for a 5x7 matrix for lower case English!

I didn't have the "dip switch doors" for either of these, so I made aluminum plates for them.

I can't believe how expensive these have become. But a brilliant design really is timeless and therefore desirable.
 
What's done to it:
-Disassembled, thoroughly cleaned
-Painted top bright white (bottom remains dark brown)
-Removed all keys and retro whited them to get brighter letters
-Covered dip switch plate with white printed decal
-Added switch to the motherboard to eliminate column 72 beep
-Added lower case rom (from another motherboard).

Here's before photo, and new pictures of the keyboard

IMG_7609_800.jpg


IMG_7623_800.jpg


DSC02058_800.jpg

On refinishing keys that have discolored, when I had time and un-diagnosed OCD, !!!AND AFTER DETERMINING THAT THE KEYTOPS WERE DOUBLE-SHOT MOLDED!!! (the ADM-3A's are), I would sand the keys with 1000-1500 wetordri (wet) and then polish them with automotive polishing compound by hand (machines can melt the plastic). This works especially well on 1970's HP equipment. Nowadays, I use automotive PLASTX (which is actually useful in several of my hobbies).

!!!DO NOT do ANY of this on pad-printed keys!!!!
 
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