deskthority

Yes, that is possible. The frequency of the clock signal that the keyboard/teensy generates can be controlled using a timer on the teensy. Did the original "external adapter box" have a switch on it to change frequencies? if so the same could be done with a teensy. If not, I would have to assume tha...

Oh neat, the HP 15C remake is one I missed. The originals are still commanding high prices in good condition. The "HP Nut" processor these calculators use feature transistors etched into silicon deposited on a synthetic sapphire crystal. It's an early form of SOI fabrication and the reason they get...

I have one of these as well and is has the same messy look to the RF absorbing/blocking material. A while back I also found an interesting PC version of this keyboard which seems to have more refined application of the goop which looks molded. https://deskthority.net/keyboards-f2/ibm-pc-emr-keyboard...

Nice find. Early 2nd gen. Assuming grey linear space invaders?

JP! wrote: ↑Vintage Ancient Cherry board.
https://www.ebay.com/itm/Ancient-1982-k ... Swx3dbnWxC

My guess would be M8 switches. i have something similar

A bit late, but the linear white version of the late clicky switch (with large stepped eyes) is very common in the later terminal boards such as ADDS and NCR. I assume towards the end of the run of space invaders they were no longer using the linear molds so made all switches using the clicky mold a...

Nice work. Definitely an interesting piece of engineering especially compared to today's disposable keyboards.

Does look like a dusting is in order, however...

I don't know what plastic they used, but Nylon != POM. Nylon is a family of synthetic polymers while POM (aka acetal or Delrin) is a specific polymer. POM is a denser material.

Actually the IC in the picture appears to have a late 1986 date code

I have 2 similar terminal boards with the silver badge. They are both marked 1390636. On is dated 1992 and the other 1995. The earlier has an IBM label and the later a Lexmark label. The bottom half of the case on the later one is slightly different as the center hole above the label is missing. IBM...

I love this! I like where you are headed. Please update this thread as you progress.

Nice work. These are really neat boards. The metal case and interesting block shape are quite unique.

Magnetic trapdoor switches are something I’ve wondered about for ages. Seems like something we should be able to make, with magnetised ferrous rings, inside plastic housings… once affordable and durable 3D printing takes off. You know the recipe: MX mount and footprint. Just picture getting two dim...

I recently met a man named Aaron who had discovered a cache of terminals from the 1980's. More on that to come. Among them were a few made by the Teletype Corporation subsidiary of AT&T. This terminal used 122 key style keyboard that I had not seen before. At first glance I wasn't expecting anything...

Doctor Click, how do the SKBM Blacks feel? NOS Zenith Data Systems Keyboard Modules. https://www.ebay.com/itm/Mechanical-Keyboard-AT-style-keyboard/292652680571?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 What is that switch? Looks very interesting Looks like KPT or something similar

Nice work snacks! A really great and rare board made usable. Looking forward to your review and post cleaning comparison.

Most if not all terminal boards with a regulator will require a supply of more than 5V as the regulator (usually some form of a 7805) will drop the voltage around 1.5V - 2V. Many terminals supplied 12V to the keyboard. Often you can remove the voltage regulator and place a jumper wire from pin 1 to ...

Can anyone identify this keyboard or switch. It appears to be a membrane keyboard. It is AT&T Teletype branded.

A square wave is indeed echoed, but at a significant attenuation, so an amplifier or comparator with an appropriate reference would work to detect key presses. IIRC, some switches conduct the pulse in the up position and block it when pressed. You may be able to use an Xwhatsit.

Wow...really interesting.

Incredible. I want one. Maybe not $260 want one. More of an "I know what I'm building next" kind of want. Bought it for $50. I'll take pics when it comes. Should be no surprises but it's a parallel ASCII keyboard which will have great vintage usability. Classic era look too! Looks homebuilt and fan...

It might be listed under MCS-48 which is the family of microcontrollers or 8748 which is the programmable version of the 8048.

Nice job. The caps fit the board..a little bit of everything. Which typewriter did the alphas come from?

Looking forward to this.

Very nice. I have never seen so many 122 key space invaders boards in one place before! Would definitely be interested if you are willing to let any of them go.

The ping is just the way they are. They ping significantly more than a model m. As far as the click problem, its sounds like the space between the barrel plate and back plate has been increased by the damage such that when you press a key the spring does not bend enough to buckle until it bottoms ou...

andrewjoy wrote: ↑You put that in the ultrasonic ?

I have cleaned cables in the ultrasonic before. As I think the OP did, leaving the connectors outside the the liquid prevents any electrical issues.

I have a DC-2214 with white alps`