[Wiki] Teletype 56K 342 AAJ - hybrid capacitive
Posted: 15 Jun 2017, 01:58
I acquired this Teletype 56K 342 AAJ keyboard because I think it goes with an AT&T 6300 series computer (or might) but in addition, I was curious about the unique font. I do love the look of these key caps as it has an almost "classic Monopoly" style font. This keyboard is branded AT&T but it's a Teletype keyboard; and probably one you would never expect to see.
It's construction is very durable but it's uniqueness is in, what I call, the rubber tactile membrane. It's used in place of individual springs but it's actually very tactile. One might not know how it was constructed until you take it apart. The thick particle board used internally on the bottom and thick particle cardboard surrounding the components on the top of the keyboard is a bit of a mystery. I don't think it would shield EMF or provide any extra rigidity. The keyboard controller is in-house made by Teletype (TTY) and I wonder if it's construction is related to the Teletype Capacitive keyboard patent that is discussed in our wiki here as Patent 3750113.
The interesting part of the rubber tactile membrane is that it's real rubber. It also has air channels underneath the membrane so that if you press down a key, it doesn't turn into a suction cup and have issues returning the key to it's upright position. The foam and foil pads are very thin and removable and look to be in great shape. Sadly, I don't have a cable for it but it would be a RJ type cable anyway.
The key caps appear to be PBT with perhaps pad printed legends? It seems a little too dark for lasered legends but a close up in below. There is a texture on the key caps.
Anyway, here are some pics below. More pics are in the wiki here: [wiki]Teletype_56K_342_AAJ[/wiki].
It's construction is very durable but it's uniqueness is in, what I call, the rubber tactile membrane. It's used in place of individual springs but it's actually very tactile. One might not know how it was constructed until you take it apart. The thick particle board used internally on the bottom and thick particle cardboard surrounding the components on the top of the keyboard is a bit of a mystery. I don't think it would shield EMF or provide any extra rigidity. The keyboard controller is in-house made by Teletype (TTY) and I wonder if it's construction is related to the Teletype Capacitive keyboard patent that is discussed in our wiki here as Patent 3750113.
The interesting part of the rubber tactile membrane is that it's real rubber. It also has air channels underneath the membrane so that if you press down a key, it doesn't turn into a suction cup and have issues returning the key to it's upright position. The foam and foil pads are very thin and removable and look to be in great shape. Sadly, I don't have a cable for it but it would be a RJ type cable anyway.
The key caps appear to be PBT with perhaps pad printed legends? It seems a little too dark for lasered legends but a close up in below. There is a texture on the key caps.
Anyway, here are some pics below. More pics are in the wiki here: [wiki]Teletype_56K_342_AAJ[/wiki].