At&t Model 513 Terminal, or Teletype 56D, or…

Talk about an identity crisis! I recently stopped by the swap meet at System Source, a computer museum just outside of Baltimore, Maryland, where I picked up this eighties masterpiece of a terminal. This…style terminal I believe is known by many monikers. This actual unit is labeled an At&t “513” on the front, and “Teletype 56D” on the back. (At&t bought Teletype Corp and often branded some of their final products with At&t nomenclature.) This unit was likely paired to an At&t Definity PBX, and simliar units could also be At&t 4425 as well as many other models (likely only minor firmware tweaks between them).

Posted on it was a sign that basically mentioned it was a “barn find”, and as such, no guarantees on it working, or ever working. As I’m a glutton for punishment, naturally I bought it. (I know the seller and he gave me a good deal on it).

Let’s see what’s inside…

This isn’t actually the first time I’ve owned one of these per se; believe it or not, I was given one as a kid, brand new in the box, thinking “hey he can play with a computer”. Unfortunately I had no idea what a serial port was, let alone a terminal at that time. I threw some basic commands at it and nothing happened, so I gave it back. Wish I had kept it! As soon as I saw it at the swap, nostalgia hit me hard, and working or not, I had to have it.

Overall it doesn’t actually look too bad for “barn find” – he did say he cleaned up the outside, but the keyboard cable kinda told a different story, its nasty! I really hoped that wasn’t an indication of what the inside held, and for once I figured it was a good idea to pop it open first, as I see a little surface rust visible on metal parts. The keyboard is mostly intact, with only the 4 key being broken off (but present). We’ll have to fix that up later.

The unit is somewhat simple to open; just tilt the monitor straight within the unit, and remove the screws off the back. Do be careful with the tilt lever though! Once the back is off, there’s nothing preventing it from tilting, so watch that as well.

Once open, I see the usual barn find signs; rusty metal, a dirty board, and a mud daubers nest. Good thing it was vacant; that would have made an interesting ride home! Also to note, you can see whats left of the DAG wire across the back of the tube, that I believe was previously made up of springs. Now they’re rusty and broken springs laying on the logic board. Its a VERY good thing this wasn’t powered up, it would have been a catastrophic ending for this vintage terminal.

The dag-gone dag is gone!

Overall it actually looks good all things considered! What likely really helped it was the fact that At&t put mesh screens on all the vents; only the most pervasive critters could get inside, and nothing that likely peed or pooped (like mice).

Between the rusty metal brackets, the wasp nest, the missing dag, and the logic board having both rust particles and some corrosion, it was obvious this thing needed some help, and full disassembly was required. I started by removing the power supply, which unplugged from the motherboard and monitor chassis. Then I removed the ribbon cable from the monitor chassis, and the logic board (with some wiring harness permanently attached) was able to removed.

From there, I was able to simply remove both the tube and the monitor chassis as one group as well. Last but not least, I removed the brightness control knob/potentiometer. Everything so far is very easy to service in this thing.

Mostly clean!

With the case now empty, it got the hose until morale improved! Ok well it got the garden hose treatment and left in the hot sun which meant it dried very quickly. Its morale was certainly better with no wasps nest or crud inside.

Stay tuned for part II of the At&t er Teletype terminal saga…