Keyboard mystery: Alps 12KC018A for TRS-80 Model III

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Daniel Beardsmore

24 Dec 2014, 18:11

Here's an eBay auction for an Alps 12KC018A keyboard:

http://www.ebay.com/itm/131105786803

It's for a TRS-80 Model III and is clearly marked "12KC018A".

The only confirmed part number for the TRS-80 Model III keyboard is 12KE010C, which HaaTa owns. "KE" means SKE_ which includes integrated dome and semi-integrated dome; HaaTa's is integrated dome.

The above code with "KC" implies SKCL/SKCM, but I don't have an eBay account, and there's no switch depicted.

mr_a500 has or had a TRS-80 Model III keyboard:

https://geekhack.org/index.php?topic=21206.0

The pictures are dead, but Google's cache shows them to be tee mount Alps. If that's true, then there's a suggestion that the tee mount version is 12KC018A, making tee mount switches SKC_. That would make sense, since tee mount switches have the same switchplate design exactly.

Anyone able to confirm PCB part numbers and switches for the TRS-80 Model III?

jacobolus

24 Dec 2014, 20:43

Judging from the keycaps, those definitely look like tee mount switches.

User avatar
Daniel Beardsmore

24 Dec 2014, 22:25

The TRS-80 Model III was introduced in July 1980, and the Model 4 in April 1983, which also fits.

However, I need to be certain, from actual photographic evidence (that we can reference perpetually) depicting at least one keyboard, with both the switches and the PCB part number.

mr_a500

24 Dec 2014, 23:21

I had a thread on Geekhack (2011?) showing my TRS-80 Model III "vintage T" ALPS keyboard PCB and switches, but like many things posted on Geekhack, it's now gone. (and I didn't save those photos because I foolishly believed they'd be safely stored on Geekhack)

I'll need to disassemble the Model III again. It's a pain though - lots of screws.

My Model III looks like it's a very early model, serial number 00046 and proudly displaying "4K RAM" on a metal badge.

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Daniel Beardsmore

24 Dec 2014, 23:36

Your photos are on Photobucket, but something's messed up there. I can't tell if they exist or not, as image hosting sites are so scummy and retarded.

mr_a500

24 Dec 2014, 23:38

That's very odd because I never uploaded them on Photobucket. I either put them on Geekhack directly or on Imageshack. (back before Imageshack became a pot of shit)

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Muirium
µ

24 Dec 2014, 23:44

Someone might have kindly purloined them. (It happens.) I'd always recommend storing them on the forum instead of a skeezy 3rd party image host (and they are all skeezy, given enough time) but in GH's case I guess there was no good solution.

I'm lazy and don't always save my pictures locally either. (The original files from the camera get archived, but not necessarily my crops.) Webwit's proven to be a better maintainer than GH has bumbled along with, but if I were more paranoid I'd save the page from my browser every time I uploaded a bunch of good stuff, so the files were kept locally and were already in context for when I might have to piece things back together.

mr_a500

24 Dec 2014, 23:48

Ah, I found one photo in my keyboard photo files:
TRS 80.jpg
I'll open it up and take a PCB photo later when I get some time.

User avatar
Daniel Beardsmore

25 Dec 2014, 00:32

You're right, it's Imageshack.

I file all my photos away on my PC. This is now my second PC where the hard drive is actually too big to fill up with anything, although I've always retained my master images.

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Muirium
µ

25 Dec 2014, 00:56

Too big!? Shoot harder! I'm keenly awaiting a NAS to ease up the pressure on my 4 drive bay Mac Pro (antient six and two thousande annum auf oure kinde, goode and graceious Lord eeditshun).

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seebart
Offtopicthority Instigator

25 Dec 2014, 11:01

Oh I'd love to get a vintage T Alps KB but it's not happening. ='( I doubt I would be able to fill my 3tb drive with images, even if all were shot in RAW. <*_*>

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Daniel Beardsmore

25 Dec 2014, 13:08

Muirium wrote: Too big!? Shoot harder!
Shoot harder, die harder …

Pictures\Incoming-2 — all the images from my 9-year-old camera that I've kept (including many of the alternative shots to ones I've used for the wiki) — totals 21.3 GB (12,688 files in 325 folders — I've hit IMGP9999 at least three times, so that's over 30,000 photos to date; the older ones get their filenames rolled back to IMGO, IMGN …). I have 538 GB left to go.

jacobolus

26 Dec 2014, 04:16

seebart wrote: Oh I'd love to get a vintage T Alps KB but it's not happening. ='( I doubt I would be able to fill my 3tb drive with images, even if all were shot in RAW. <*_*>
500 pictures/day and you can fill that in 1–4 years depending on your camera’s resolution.

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seebart
Offtopicthority Instigator

26 Dec 2014, 10:07

jacobolus wrote:
seebart wrote: Oh I'd love to get a vintage T Alps KB but it's not happening. ='( I doubt I would be able to fill my 3tb drive with images, even if all were shot in RAW. <*_*>
500 pictures/day and you can fill that in 1–4 years depending on your camera’s resolution.
OK that's a realistic calculation BUT what about the time needed to take 500 pictures a day, let alone 500 good pictures a day. ^_^

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scottc

26 Dec 2014, 11:37

Who said they needed to be good?

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Muirium
µ

26 Dec 2014, 11:40

~50 pictures a day * the 3000 days I used my first digital camera (a point and shoot Olympus) = the 200 gigabytes in my iPhoto library when I finally got a DSLR. Since then I've taken a few terabytes. Large portions of which are jpegs from borrowed cameras, which are in the 8-16 megabytes per file range. My 8 megapixel 350D shoots 3-5 megs per jpeg (minimum "fine" compression). I never save raws, the camera's too slow for that to not get in my way.

A friend of mine who does (on a 12 megapixel Nikon D5000) is on his second 3 TB hard drive. And he shoots less often than I do. But always raw + jpeg. He is literally yet to do anything with any of those raws. I frequently ask him!

I don't shoot 50 shots every day. It's often zero, especially this time of year in general. But on occasions I'll do hundreds, like every DSLR wielding shutterhead. Once you've got that thing out, you're sure using it!

The blessing of large hard drives is you don't have to waste the thousands of hours it would take to trim down your library. I do the opposite: I simply flag pictures I like at a glance, and pick from those when sharing. But my deep archive is intact, and invaluable when it comes to retrieving things you didn't realise were important at the time. Storage is cheap. Ergo more storage!

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seebart
Offtopicthority Instigator

26 Dec 2014, 14:44

I guess it's the way you photograph. I generally shoot less (15-30 shots per keyboard shoot) and then find 1-5 of those to be useable. I still drop the rest on my HD in full resolution. Of course with the current GB prices the glory is it does not matter at all.

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Daniel Beardsmore

26 Dec 2014, 14:56

Well, yes, the more competent you are, and the better your camera is, and the better your setup is, the fewer photographs you need, since you'll be getting them right every time. Further, taking good photographs means far less time required to retouch them — just to remove hairs from the picture, not because the colour balance is out of wack in every single photograph.

On the other hand, if the photos aren't going on the wiki, all those photography skills aren't amounting to anything ;-)

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seebart
Offtopicthority Instigator

26 Dec 2014, 15:12

right but I do also know people that are quite skilled with their camera and just shoot 50-100 pictures spontaneously and then see if any of those turned out great by chance. A little silly in my opinion but if someone enjoys working that way why not. It also has to do with the subject. Keyboards are not ideal subjects for spontaneous "action" photography. What comes to my mind is that long exposure shot by madhias of him typing which is a little different than what we usually post around here.

That reminds me I wanted to reshoot those FK-2002 blue Alps photo´s of mine in the wiki. They were a little "rushed".

Here you go:http://www.techradar.com/news/computing ... dd-1264941

Try filling that with images. :shock:

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Daniel Beardsmore

27 Dec 2014, 14:37

I just found proof:

http://www7.ocn.ne.jp/~hisao/image/paso700.htm

Alps vintage tee mount is SKC-something!

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seebart
Offtopicthority Instigator

27 Dec 2014, 14:40

Nice! (-_-)

mr_a500

27 Dec 2014, 15:40

What the hell? You mean I opened my TRS-80 for nothing? (28 screws, slot, phillips, even one robertson!)
TRS-80 Model III keyboard PCB.JPG
I also opened my Japanese green T ALPS 6112884, just because it's Christmas:
6112884 PCB.jpg
Then, since I already trashed the room with open keyboards, I opened the TI-99/4A. This one surprised me, because the (somewhat ratty) PCB is not ALPS, but made by "General Keyboard, Instruments Division")
TI keyboard PCB.JPG
But the switches look identical to T ALPS:
TI switches.JPG
Either General Keyboard made keyboards with ALPS switches, or this is a T ALPS clone.

Edit: The sliders are not exactly identical. They're also thinner - so although T ALPS keycaps will fit on this keyboard, TI-99 keycaps don't fit on T ALPS keyboards. This is likely a clone.

User avatar
Daniel Beardsmore

27 Dec 2014, 16:05

Not for nothing, no — always good to have more evidence, thank you!

Interesting PCB on that TRS-80 — nothing like normal Alps PCBs.

Also, the TRS-80 should have some chip dates that might prove that the vintage tee predates SKCL, since the only confirmed dates so far (M0110, M0110A and Pasopia 700) are from 84–85, which would make them a later design! The TRS-80 Model III is reported to be a 1980–1983 machine, so a date in that range will confirm that this is the older design.

The date codes on the other two are of course also useful. I was looking at IBM Japan photos and I found one showing what appeared to be an Alps PCB, but no codes, and being Soarer's photo, I can't ask him as he's vanished. However, you delivered instead :) (Though photos showing the switches would be nice to have, as there are so few pictures of those IBM Japan boards.)

And those yellow ones again — I've seen those before, in a mysteriously unbranded PCB. I don't know if they're intentionally yellow, or if the cream plastic just turned yellow (since it doesn't seem to normally).

mr_a500

27 Dec 2014, 16:21

Daniel Beardsmore wrote: Also, the TRS-80 should have some chip dates that might prove that the vintage tee predates SKCL, since the only confirmed dates so far (M0110, M0110A and Pasopia 700) are from 84–85, which would make them a later design! The TRS-80 Model III is reported to be a 1980–1983 machine, so a date in that range will confirm that this is the older design.
I already checked for chip dates. Strangely, the TRS-80 keyboard doesn't have a single chip on it - no diodes, nothing. It's just switches on a PCB with a connector.

All the chips on the TRS-80 motherboard start with 80 and as I said, this is an early model, so the keyboard is almost definitely made in 1980.

mr_a500

27 Dec 2014, 16:30

seebart wrote: Oh I'd love to get a vintage T Alps KB but it's not happening. ='(
Why don't you get one? New in original box, $24.95 US plus shipping:

http://www.ebay.com/itm/380994210683

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seebart
Offtopicthority Instigator

27 Dec 2014, 16:34

Because everything outside the EU is a no go in terms of shipping and German customs for me. I miss out on A LOT of stuff that way.

User avatar
chzel

27 Dec 2014, 16:35

It's the "plus shipping" that kills it for me!

mr_a500

27 Dec 2014, 16:40

Here in Canada, we expect to be ripped off with monstrous shipping charges. The Americans get free shipping all over the damn place, but a little hop over the border and we're charged more than if you shipped something half way around the world.

Still, if I never paid those horrible shipping charges I'd have 1/10 of the keyboards I have. It's hard to find good (old) keyboards in Canada. All the good stuff is south of the border.

User avatar
Daniel Beardsmore

27 Dec 2014, 16:53

mr_a500 wrote: I already checked for chip dates. Strangely, the TRS-80 keyboard doesn't have a single chip on it - no diodes, nothing. It's just switches on a PCB with a connector.
Doesn't seem strange to me. Interestingly, BBC Micro keyboards have three or four chips on them; I don't know what they do, though. Not one big chip, but three or four little chips (details from my "Type 1" AWC/Futaba keyboard):
  • Texas Instruments SN74LS251N "8-Line To 1-Line Data Selectors/Multiplexers With 3-State Outputs"
  • Motorola SN74LS163AN "Synchronous 4-Bit Binary Counters 16-PDIP 0 to 70" or "BCD Decade Counter/4-bit Binary Counter"
  • Texas Instruments SN7445N "BCD to Decimal Decoder / Driver"
  • Texas Instruments SN74LS30N "8-input positive-NAND gates"
IC descriptions vary from site to site.

I know that one of the Versatile Interface Adapters (VIAs) controls the keyboard, so it seems that the controller duty is split between the primary 6522 VIA and a series of dedicated chips.

From 8bs.com:
8bs wrote:The keyboard circuit connects via PL13. A 1MHz clock signal is fed to a 74LS163 binary counter, the outputs of which are decoded by a 7445 decoder driver circuit. These outputs drive along one row of the keyboard matrix and each row is driven in turn. If any key is depressed the 74LS30 gate will produce an output when that row is strobed and this will interrupt the computer on line CA2 of IC3. On this interrupt, the computer will enter the key reading software. In order to discover which key was pressed, the microprocessor loads directly into the 74LS163 the address of each key matrix row allowing it to interrogate each row in turn. Also, the microprocessor loads into a 74LS251 data selector, the address of each specific key on that row, i.e. column addresses. In this way, the microprocessor can interrogate each individual key in turn until it discovers which one was depressed and causing the interrupt. Once read, the keyboard regains its free running mode.
I think the VIA just connects the 6502 to the keyboard circuitry. So there you go, a keyboard without a dedicated controller chip.
mr_a500 wrote: All the chips on the TRS-80 motherboard start with 80 and as I said, this is an early model, so the keyboard is almost definitely made in 1980.
Codes like 80__ (YYMM)? The code "12KC018A" is presumably an early code. I think I'll start putting years in the codes table, too, as that might prove useful one day.

mr_a500

21 Jan 2015, 20:34

mr_a500 wrote: Then, since I already trashed the room with open keyboards, I opened the TI-99/4A. This one surprised me, because the (somewhat ratty) PCB is not ALPS, but made by "General Keyboard, Instruments Division")

Image

But the switches look identical to T ALPS:

Image

Either General Keyboard made keyboards with ALPS switches, or this is a T ALPS clone.

Edit: The sliders are not exactly identical. They're also thinner - so although T ALPS keycaps will fit on this keyboard, TI-99 keycaps don't fit on T ALPS keyboards. This is likely a clone.
Ah ha! I knew I saw another TI-99 keyboard that was actually labelled ALPS:
TI-99.JPG
TI-99 ALPS.JPG
http://www.ebay.com/itm/281571442793

It's "SKC" so it must be T-ALPS. I'd like to see the switches in this to compare.

I still think it's very strange that my TI-99 keyboard is "General Keyboard, Instruments Division" with T-ALPS-like switches - when they also had actual ALPS keyboards in the TI-99/4A.

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