deskthority

After that sell it to me

clickykeyboards wrote: see for some photos

http://www.clickeykeyboards.com/model-m ... years-old/

I will take some time this weekend to setup my macro lens and lighting rig and will add additional PCB photos, for reference.

Regarding the stamp it looks like it's top middle of the case interior?

Interesting, it looks like the rivets on your board were made by machine rather than by hand.

Now that we have identified 3 specimens of the same PC-compatible controller, it seems like we have discovered a new species here.

That is, this PCB has as socket and a tape-covered EEPROM instead of a normal chip found on normal late '85 early '86 1388032, 1390120, 1390131, etc. This is a new '84-85 controller. It's funny because we already have something thought of as the "1st generation" controller....and these precede it.

What else is interesting is that these specimens have popped up in both the US (E29) and UK (Chyros)...so I guess both factories got their controllers from the same place...makes sense. At first I thought I was seeing a Grennock exclusivity here (because of the extra label on the back plate, which from my observation was exclusive to the Grennock boards).

bitslasher wrote: At first I thought I was seeing a Grennock exclusivity here (because of the extra label on the back plate, which from my observation was exclusive to the Grennock boards).

That'd mean my board wasn't made in Greenock though, which would be... interesting Oo .

Yeah I'm not sure about the whole label situation. I'll use key words like "my observation" to open a door for someone to correct me. So please someone chime in and tell me if that's a good assumption or not!

If only I could find myself an industrial Model M... Haven't even gotten myself an official Model M yet.

They IMHO are the best boards, as far as mechanism goes. I'm biased I guess. I've typed on them for 22 years. First was an M2 in 1993 that came with my first computer an IBM PS/1 (age 15), then I got an 1391401 in 1996 and have used it ever since. Best boards ever. Just spent a bank on a Topre HiPro and have not been that impressed. Accuracy is down. I find myself accidentally pressing keys with fingers I didn't realize I rested on the board. These are 45g. Not sure what an M is (I've heard 70g???) but it was the easiest to type on to me.

They truly are life-long boards. Don't get hung up on getting the most exotic industrial from 1985 or the SSK that is very hard to find. Go on eBay spend around $50 and get a run of the mill 1391401 from the late 80s or early 90s (1987-1992) and you'll have the best board. Why? They're used. They're broken in and they'll type like a dream. I have an Dec 85 board (industrial) and an Apr 86 board (1390131) and neither is as good as my April 1989 board. They both looked hardly used when I got them. I spent a lot of money on those 85, 86 boards. That '89 board I got for free off a PS/2 Model 80 server in a storage building when I was working at a RadioShack as a college student back in 1996. . It still sets at my desk at work (I'm a software developer) so I've used it all day every day for that long!

E TwentyNine wrote:

clickykeyboards wrote: see for some photos

http://www.clickeykeyboards.com/model-m ... years-old/

I will take some time this weekend to setup my macro lens and lighting rig and will add additional PCB photos, for reference.

Regarding the stamp it looks like it's top middle of the case interior?

I had some time this weekend to look at the keyboard and took a few additional photos and added them to the link below.

http://www.clickeykeyboards.com/model-m ... years-old/

The only dates that were clearly visible were the ink stamp on the back of the front case interior that reads AUG 15 1985.

Date on front of PCB controller is 18 85 which might translated into 18th week of 1985 (April 29 - May 3, 1985)
(no other dates on the back of PCB keyboard controller)

Looking at the back of the keyboard, there is the cutout in the case for the IBM certificate, but it is empty on this keyboard.

What's the lettering/symbol to the left of "7J" on the board? Can you get a clearer pic of that?

Is your case white painted black or molded black plastic?

bitslasher wrote: They IMHO are the best boards, as far as mechanism goes. I'm biased I guess. I've typed on them for 22 years. First was an M2 in 1993 that came with my first computer an IBM PS/1 (age 15), then I got an 1391401 in 1996 and have used it ever since. Best boards ever. Just spent a bank on a Topre HiPro and have not been that impressed. Accuracy is down. I find myself accidentally pressing keys with fingers I didn't realize I rested on the board. These are 45g. Not sure what an M is (I've heard 70g???) but it was the easiest to type on to me.

They truly are life-long boards. Don't get hung up on getting the most exotic industrial from 1985 or the SSK that is very hard to find. Go on eBay spend around $50 and get a run of the mill 1391401 from the late 80s or early 90s (1987-1992) and you'll have the best board. Why? They're used. They're broken in and they'll type like a dream. I have an Dec 85 board (industrial) and an Apr 86 board (1390131) and neither is as good as my April 1989 board. They both looked hardly used when I got them. I spent a lot of money on those 85, 86 boards. That '89 board I got for free off a PS/2 Model 80 server in a storage building when I was working at a RadioShack as a college student back in 1996. . It still sets at my desk at work (I'm a software developer) so I've used it all day every day for that long!

You NEED to try a Model F. This is your next major goal in life.

The problem with that is, once you try a model f you cannot go back to an M , and to get one with a good layout is hard! Best (cheapest and most available option) would be a model F 122.

Honestly, I prefer my Unicomp EnduraPro 104 over my F 122. The F 122 has some critical design flaws in that the mechanism is poorly supported internally, and too much flex is allowed to occur.

They can be worked around with a rebuild and a bolt mod, though - I need to do that to mine. The smaller Model Fs, because they don't have as large unsupported spans, are much better.

Also, all Model Fs have rather poor stabilization for the 2U+ keys (except the spacebar, which is fairly similar to Model M stabilization), such that they really need to be hit over the buckling spring mechanism or they bind. The XT board has hat keys to force that, but the 122 doesn't. However, a 122 can be fixed by swapping those keys for Model M keys, and installing the Model M stabilization inserts, so there is that (while you've got the 122 open anyway).

Each to his own, i have 2 122Fs never bolt modded them and i don't feel any flex whatsoever. I do however slightly bend over the middle tabs, just to be sure its tight.

It is also a metal body bolted by 4 bolts to a heavy metal back along with 2 locating pins, i don't see how it can flex.

You don't even need to open the F to install the model M stabilisers. I have never noticed a problem with the F style bar stableisers, the space bar is better than an M IMO as the thinner bar is not as heavy.

FLEX?! Oo You've got flex in a 4 kg metal beast? oO

I also never had any stabiliser issue on my F122 like you described =o .

Chyros wrote: FLEX?! Oo You've got flex in a 4 kg metal beast? oO

I gotta try that some time, sounds more like a workout.

It's flex in the middle unsupported span that makes tactility inconsistent and poor. Doesn't take much at all to throw things off. (And, IMO, the outer keys are a bit inconsistent too, wouldn't be surprised if the foam is rotten.)

bhtooefr wrote: It's flex in the middle unsupported span that makes tactility inconsistent and poor. Doesn't take much at all to throw things off. (And, IMO, the outer keys are a bit inconsistent too, wouldn't be surprised if the foam is rotten.)

I totally believe you, it's a long keyboard after all. My 122 is an M, I wonder if that's even worse. I have not used it in ages, I'll have to check.

Very nice find, enjoy !

To bring up the original topic again (:P), how do you know if your keyboard is a prototype? Because I've been thinking about it and it'd be really exciting if it were! The no-label thing kind of set me off on it because it so obviously never had a label in the first place that I'm wondering what it is I'm holding here right now (especially considering it's ANSI with German lock legends and those weird terminal caps too) . When I know more about it I might do an in-depth video about it at some point .

Chyros wrote: To bring up the original topic again (:P), how do you know if your keyboard is a prototype? Because I've been thinking about it and it'd be really exciting if it were! The no-label thing kind of set me off on it because it so obviously never had a label in the first place that I'm wondering what it is I'm holding here right now (especially considering it's ANSI with German lock legends and those weird terminal caps too) . When I know more about it I might do an in-depth video about it at some point .

In my case, I believe the main reason it was suggested was because of the handwritten designation on the socketed chip label. I confirmed with an old IBMer that codename was used for the keyboard firmware (Ferrari).

Yours and mine have other similarities - socketed chip, the controller board datecode being one of the earliest seen, the hand-assembled backplate assembly, different case, some other things, would have to review/recompare.

Clicky's is a little different - he has a "short form" board and a soldered chip. I'd definitely like to see more detailed photos of his and yours.

Took a little while but here's some more, as promised; I made a video instead of more pictures though. Thought that would be more comprehensive .

Oh my god I want that. One of my grails. I hope you enjoy it as much as I would.

Maybe the chip with the opaque sticker on top is an EPROM?

jacobolus wrote: Maybe the chip with the opaque sticker on top is an EPROM?

Yeah that's what somebody suggested in the comments on Youtube, they said

It's an EPROM memory or a microcontroller with EPROM memory (I haven't found exactly this one, but it's something like "TMS7742JDL"). The sticker covers a window, under it is the memory itself - don't remove the sticker, the UV light could erase it -> making keyboard unusable...

What is EPROM?

Erasable Programmable Read Only Memory.

Essentially, you have the following classes of ROM:

Mask ROM: Fabricated with the data that it'll always have - the cheapest type of ROM to make in mass quantity, but very expensive to change the data.
OTP ROM (One-Time Programmable ROM): Can be programmed by writing to it with high voltage, but once that's done, that's it, that's the data you've got on there.
EPROM: Similar to an OTP ROM, but with a window in the top. UV light can reset these, so they can be rewritten. The sticker makes sure no light can get in to accidentally erase it.
EEPROM (Electronically Erasable Programmable ROM): Similar to an EPROM, except instead of a window to erase it using UV, there's an erasing voltage that can be applied to erase the whole chip.
Flash: EEPROM that is organized in blocks, and erasing happens on one block at a time, instead of the whole chip.

I don't think it's an EPROM: It was quite common for chip packages to have a protruding metal plate on the top of the chip back in the days. On an EPROM they would probably have put a more oblique kind of sticker.





http://www.chipsetc.com/vintage-compute ... dware.html

But they did make one time programable versions , they would have no need for a window for UV erase.

I am guessing its just a keyboard controller.

The chip on that IBM will prob be a very early run of the chip, to be in a plastic package ( at least back then) the chip had to consume less than 0.5w, if you did not know the power draw then it makes sense to put it in a ceramic package until you have tested the physical chip sure the price for plastic vs ceramic is about 100x ( more for the ceramic) but if your doing an early small test run its not that big of an issue.

Mill spec stuff will usually stick to them for the durability.

BTW, the unpopulated part of the PCB is probably because they used the same controller PCB for 122 key terminal keyboards. Those have a third membrane connector that goes into the J6 spot. Rxx are resistor spots, U4 and U5 are the spots for logic chips.

andrewjoy wrote: But they did make one time programable versions , they would have no need for a window for UV erase.

If it’s a prototype board, then being able to erase it would make some sense.