Amtelco Unified Keyboard - Cherry MX Black

snuci · 17 Jul 2016, 20:43

I recently acquired the Amtelco Unified keyboard that was on eBay from Canada and cleaned it up. It has Cherry MX blacks and is a keyboard from 1990. You'll notice that the keyboard PCB is split up into two boards. The bottom board help the speaker and other electronics while the top board was dedicated to key switches. The key caps are mostly double shots but has some specialized engraved key caps that have worn away. I left the keyboard label strip on that makes this easily identifiable as to what it did when it was in service.

Here are some pics:

: Amtelco Unified - keyboard top; Amtelco Unified - keyboard top.JPG (300.72 KiB) Viewed 3501 times

: Amtelco Unified - keyboard bottom; Amtelco Unified - keyboard bottom.JPG (172.93 KiB) Viewed 3501 times

: Amtelco Unified - keyboard mechanism top; Amtelco Unified - keyboard mechanism top.JPG (317.13 KiB) Viewed 3501 times

: Amtelco Unified - keyboard mechanism bottom; Amtelco Unified - keyboard mechanism bottom.JPG (393 KiB) Viewed 3501 times

: Amtelco Unified - PCB markings 1991; Amtelco Unified - PCB markings 1991.JPG (365.04 KiB) Viewed 3501 times

: Amtelco Unified - Cherry MX black key switches; Amtelco Unified - Cherry MX black key switches.JPG (252.37 KiB) Viewed 3501 times

: Amtelco Unified - spacebar stabilizer; Amtelco Unified - spacebar stabilizer.JPG (234.53 KiB) Viewed 3501 times

: Amtelco Unified - mix of double shot and engraved key caps; Amtelco Unified - mix of double shot and engraved key caps .JPG (192.37 KiB) Viewed 3501 times

: Amtelco Unified - back profile; Amtelco Unified - back profile.JPG (237.41 KiB) Viewed 3501 times

: Amtelco Unified - front profile; Amtelco Unified - front profile.JPG (228.64 KiB) Viewed 3501 times

MrNorse · 18 Jul 2016, 01:37

It seems so strange seeing a phone style keypad on a keyboard.

snuci · 18 Jul 2016, 02:10

MrNorse wrote: ↑It seems so strange seeing a phone style keypad on a keyboard.

Nice catch. Yes, this keyboard was used for telemarketing so it may have been used as the phone as well so the keypad would be arranged like a phone instead of the usual way.

terrycherry · 18 Jul 2016, 06:48

Nice shared. I have no idea why it need a big PCB on the top. It waste the space and gain the weight.
The telephone keypad just like the [RJ-12][Canada][2003.01]MITEL SUPERSET 700 Console Keyboard(MU190EA)

: 01.JPG (107.27 KiB) Viewed 3447 times

The Hong Kong Housing Authority still using it until 2015mid.(I took the photo in 2004.11.30)

I never know what switch it has. Do you know that?

Harshmallow · 05 Jan 2017, 00:44

Snuci, my Amtelco just arrived today and I was excited to find out that all of the key caps on mine are double shots for some reason. They all look to be in great shape, and otherwise the keyboard looks to be in similar condition as yours. I think it's the same seller as well - he must have gotten hold of another one or perhaps several. This one also came with a 'keyboard condom' on it and that's likely why the keys are in such good condition - because call centers are filthy places with lots of human traffic (I worked at many

) and they probably wanted to protect their investments from all the dirty hands using the boards.

Anyways, I will clean mine off and try to take some decent photos. They likely won't be as good as yours, but I do want to show the double shot versions of the same block of keys you have as engraved versions. I'm also curious to see the internals. Perhaps mine is a slightly older model...or the one you have had a few key caps replaced with cheaper superseded parts at some point in its service life.

Either way, $20 + $12 shipping for 146 vintage MX blacks and a beautiful battleship like this is a good deal in my books!

snuci · 05 Jan 2017, 01:50

Hi Harshmallow,

Congrats on the acquisition! They really are nice boards with great switches and a "How can I say no?" price. I also had the rubber cover on mine too but had removed that and cleaned up the board. It looks like I had a couple of dirty engraved caps. That "Disc" key cap is just dirty. I have ordered one of those ultrasonic cleaners so I'm curious if it will clean the crap in the engraved grooves well.

In any case, I look forward to pics. We'll have to compare dates of manufacture.

zslane · 05 Jan 2017, 01:51

Maybe someone can explain to me the (historical) rationale behind having stepped keycaps that only provide a 1u surface to aim for with your fingers, while taking up more than 1u of layout space.

XMIT · 05 Jan 2017, 02:33

Just guessing but that would avoid the need for a stabilizer. I'm not sure why that would be a design goal, though.

ideus · 05 Jan 2017, 02:40

A one unit top allows larger key caps to be balanced with no stabilizer. Stabilizers were used for space bars only. The hat type key caps were very common in the era of the XT PC. I have a couple of Cherry sets that feature the same characteristic. Also, most of model F and M IBM XT boards also use those type of caps. This particular model features the same hat type but with larger width key caps. I really cannot understand the logic of these type of key caps. Maybe, it was only due to styling.

snuci · 05 Jan 2017, 02:51

I honestly think it was just to make the combined key cap footprint on the IBM PC keyboard to be squared off so the keyboard mechanism cutout was perfectly square regardless of 83 key or 84 keys.

Spoiler:

This eliminated the jagged sides of the cutout that would be specific for 83 or 84 key mechanisms. I just think everone else copied IBM so it became a "thing" after that. I don't see any reason other than filling in space (like the long "Q" on the Alps AKB-3420).

Spoiler:

Harshmallow · 05 Jan 2017, 03:03

It kinda looks like they wanted to save some money on putting in extra 1u switches/stabilizers and just went with varying sizes of 'brims' to fit into the key module cutouts they had put into the metal upper case. Yeah, btw the entire thing - except for the little grille at the top with the logo and speaker underneath it and the triangular, beige side trim pieces - is metal. This beast is quite heavy.

I'm just picturing a couple designers that had proudly cut out all of their key module holes in the case, had the factory produce thousands of 'perfect' cases and then went 'S**t! We cut out the wrong size modules! Screw it, just give the keys some hats to fill in the gaps!'

Edit: Exactly, I had this message typed out and walked away while Snuci had posted. It just seems like filling in space for the sake of symmetry/appearance and/or convenience.

Harshmallow · 05 Jan 2017, 03:53

Ok, here are a few quick photos - I just wanted to get some info up to compare the manufacturing dates. I just moved and don't even have the tools to fully disassemble this, but I got enough of the back panel off to take out the speaker/smaller PCB and snapped a photo of the tag on the main PCB as well. Looks like mine is an 89...could explain the use of more doubleshots.

*These are just cell phone pics, plus I still haven't cleaned it at all. Just excited to show some photos lol, so I didn't want to be patient.

Spoiler:

snuci · 05 Jan 2017, 04:05

Interesting. Yours is a Rev C and mine is a Rev E. That would make a difference. By the way, don;'t try to take it anymore apart. The keyboard mechanism PCB is a nigfhtmare to take out and put in.

Harshmallow · 05 Jan 2017, 04:18

snuci wrote: ↑Interesting. Yours is a Rev C and mine is a Rev E. That would make a difference. By the way, don;'t try to take it anymore apart. The keyboard mechanism PCB is a nigfhtmare to take out and put in.

Yeah I noticed some oddities looking into the case from the part I had off. I mean, even the little PCB has a small, almost floating metal panel that screws into the back, 90 degree angled panel. nothing simple about this assembly.

I can see the two main screws holding in the PCB to the case...and they're going through what look like metal risers that each have a piece of foam/pad between them and the PCB. I have no idea how I would center those again to try to reinstall the case screws through the PCB. The plate and PCB shifted a little during shipping as well, but I was able to push it back into place.