Help Dating a Silver Badge Model M

[rocco_16v]

I just got this silver badge Model M (to pair up with my silver badge M122) but its lacking both the external sticker (birth certificate) and the internal stickers on the back plate.I know getting a definitive date will be next to impossible (unless IBM answers my inquiry with a date) but I want to ask the community here for your input. I also wanted to at least document and make available as much info as possible on it to help others.

Here is the images link: https://imgur.com/a/fY10M9s

I posted this as well on r/modelm and got good feedback from the community there. If you happened to see my post there I apologize for the double posting.

Thanks.

[clickykeyboards]

@Rocco,

Nice early model M example. Looking at your photos of the controller and keyboard internals, it definitely is an early 1984/1985 model M keyboard. Without the IBM paper labels on the back of the keyboard case or back of the curved plate, it is hard to assign a more specific date.

Too bad about the keyboard case condition and the paint condition and the leaking dye sublimation on the alphabet keys.

Do you have any other photos before the LED overlay was removed?

It is hard to tell from the thickness of the "black paint", but I looks more like "black vinyl dye" based on how thick the coating is.

For reference, here is an August 1985 model M keyboard

http://clickeykeyboards.squarespace.com ... -keyboard/

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aug-1985-model-m-3.jpg (171.67 KiB) Viewed 8871 times

aug-1985-model-m-4.jpg (105.97 KiB) Viewed 8871 times

aug-1985-model-m-5.jpg (116.65 KiB) Viewed 8871 times

[rocco_16v]

Thank you for this! It makes me happy knowing that the black covering is potentially original. The black finish and the missing piece in the bottom case will be professionally repaired in the future. I will once again look inside the case for that date stamp in case I missed it.

The only pictures I have before the LED panel fell off are from the auction posting since the panel came off as I was un packaging it upon delivery. https://imgur.com/asd2EuA I did not measure the thickness of the black coating on it but the backside of the pieces that came off were gray in color and smooth in texture. Additionally the surrounding area of the led panel location is perfectly smooth unlike a non coated Model M (at least the ones I own and have seen).

[rocco_16v]

Took another look at the LED overlay (trying to figure out why it does not align properly) and comparing the images between yours and mine I noticed the recess for the LED overlay on my keyboard is not the same as yours. I looked at other images from the web and all the silver badge images I found seem to match yours.

I took a measurement (H x W) of the recess area for the LED overlay from my other Model Ms ('94 Lexmark and '13 Unicomp) and those measure (22mm x 77.5mm). The recess on this "black" Model M is 20mm x 78.5mm and the distance between the top of the recess and the edge of the bezel measures 5mm. This explains why the LED overlay does not align properly with the holes in the case and makes me believe it was replaced at some point in time.

[JP!]

Thank you for this! It makes me happy knowing that the black covering is potentially original. The black finish and the missing piece in the bottom case will be professionally repaired in the future. I will once again look inside the case for that date stamp in case I missed it.

The only pictures I have before the LED panel fell off are from the auction posting since the panel came off as I was un packaging it upon delivery. https://imgur.com/asd2EuA I did not measure the thickness of the black coating on it but the backside of the pieces that came off were gray in color and smooth in texture. Additionally the surrounding area of the led panel location is perfectly smooth unlike a non coated Model M (at least the ones I own and have seen).

To me the assembly is absolutely period correct to an early Model M from 1985 but just wanted to mention that it is very difficult to say if this coating is in fact original. In short, I would lean towards this having been painted at a later date, likely many years ago. Paint or coated finishes essentially disappeared with the Model F and I don't know of any other Model M's with such a coating. The introduction of the Model M was designed to cut costs and additional steps would no doubt add cost. Something just seems very different or weird with this case and the more I look at it, the more anomalies that I can see. Either way it is certainly an interesting board and thanks for sharing. Now I want to start looking at the internals of more Model M examples through the years.

-If you look at Clicky's board and my black GE Model M from 85' for example the texture is very different. There is no texture inside the black GE M case so different processes and materials were used. The black GE could be scratched and it's color would not change.

-"The plastic under the coating (surrounding the LED template sticker) looks flat and smooth (non textured) unlike other Model Ms"
Definitely strange. Can it be that the entire top shell is smooth rather than textured?

-Unusual LED overlay dimensions - 2mm shorter than standard

-Nothing conclusive but beige pads instead of black. Seems like a simple detail to exclude since black instead of beige did exist as seen here.

m3.jpg (34.62 KiB) Viewed 8542 times

-Different case part? Edit: My case has this part number but at a different location

RV4oNQt.jpeg (568.79 KiB) Viewed 8542 times

[Edit]:
Did you find one of these foam assembly supports? They came with the earliest generation of Model M's.

[rocco_16v]

I have to be honest I got over excited about it. I agree with you as both the features you pointed out were my first indicators on thinking the coating was not original in the first place. My initial goal was to remove the coating completely, but seeing another board with similar looks made me think it could potentially be original and worth to repair it. Now I don't really know what I'm gonna do either remove it or repair it.

The foam wedge was not found inside the case, if it ever had it its long gone now.

Additionally would you happen to know if the size of the LED overlay has varied at any point in during manufacture of the Model M? I f so is it possible to source a replacement?

Thank you!

[JP!]

I have to be honest I got over excited about it. I agree with you as both the features you pointed out were my first indicators on thinking the coating was not original in the first place. My initial goal was to remove the coating completely, but seeing another board with similar looks made me think it could potentially be original and worth to repair it. Now I don't really know what I'm gonna do either remove it or repair it.

The foam wedge was not found inside the case, if it ever had it its long gone now.

Additionally would you happen to know if the size of the LED overlay has varied at any point in during manufacture of the Model M? I f so is it possible to source a replacement?

Thank you!

I'm with you on that one. It's a tough call on a what to do. As they say in the car world: "it's only original once". This case is an anomaly to me at this moment. It is perhaps unique enough that you might be better off leaving it as it is. Not sure if it can be touched up as that texture is probably impossible to match. Additionally, it seems that this coating was applied professionally as it looks well done with a consistent texture but perhaps you or your paint guy might have more insights on the quality. I think it would be very time consuming to completely remove the old coating from every nook and cranny. I do wonder if the entire top shell is smooth or if it is textured? The overlay though is really throwing me off. It should be the standard size that you would see on Millions of Model M's that were produced through the years. I think a custom overlay scaled to fit would need to be made if you wanted to make it look it's best.

Even looking at early model M's without LED's you still see a cutout that look like the perfect size for an LED overlay while yours is 2mm shorter which looks a bit out of place next to the lines of the function row keys.

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bq8tyOZ.jpeg (314.18 KiB) Viewed 8426 times

Initially I was thinking that maybe the case had been swapped out with a newer case. Looking at the top shell it appears there is less material and reinforcement which makes me think later era Model M where some cost cutting was necessary. Model M's eventually became lighter over the years with the earliest models weighing the most. A later model case or top shell doesn't address the unusual overlay situation and Square label M's being less common than say oval / pill logo Style M's made in the millions so I don't think this theory tracks. Actually the reinforced screw post design doesn't really change even up the Lexmark era years later. Also that same part number 1351554 is present on my 1985 Model M, just in a different location along with the M-1 marking.

Later Lexmark Model M:

lexmark.jpeg (94.91 KiB) Viewed 8231 times

Your 1985 Model M Vs. 1985 Black GE branded Model M

topshell.jpg (593.53 KiB) Viewed 8426 times

One thing that tells me your case (at least evident from the bottom shell) is very early, at least period correct to the keyboard module is a lack of these rectangular notches present above the label / birth certificate. These seemed to have become the norm by late '85.

With:


Without:

1390131.jpeg (639.7 KiB) Viewed 8412 times

In summary I can't tell you what all this means. Was the paint just a cool customization someone did, was it subterfuge to hide any flaws or defects, or perhaps a weird customization IBM did as some sort of very early draft / prototype case thus explaining certain characteristics not present on standard production models?

[clickykeyboards]

@Rocco. Do you have any information about the provenance (chronology of the custody or previous location of an object) of this model M keyboard?

After running ClickyKeyboards since 2004, I have collected some unique pieces from other IBM'ers who worked across IBM factories and distribution facilities in Lexington, Kentucky; Boca Raton, Florida; Armonk, New York; and Charlotte/Raleigh, North Carolina.

Certainly the internal keyboard assembly (barrel plate with buckling springs installed and key stems/key caps) and the controller are IBM original parts consistent with 1985. From the raised case markings on the lower plastic case (1351555), this is consistent with other IBM nomenclature for parts. I have also personally seen IBM screw the internal assembly to the lower case on some early model M keyboards (as well as IBM electronic typerwriters).

• The smaller cutout of the LED sticker is atypical.

• The peeling black paint for a model M case is also atypical.

• The worn dye-sublimation of the lettering on the keys is something uncommon with most vintage model M keyboards, but something a few others have seen first-hand in the past.

Going forward, you might want to keep the peeling painted case as-is for the sake of authenticity and save it for the next generation.

The thicker curved metal plate assembly, with shiny coating and circuit layers glued to the curved plate.. along with the internal PCB controller with the flashable ROM chip is certainly unique and adds to the mystique of this model M in your hands.

To make this model M keyboard usable as a daily driver, you could certainly substitute a replacement top and bottom case assembly from https://www.clickykeyboards.com/product ... -4-screws/ or find other sources on ebay.

I have seen some interesting custom keyboard cases done with Cerakote (ceramic coating) and with hydro dipping (aka water transfer printing or immersion printing). for example: https://www.facebook.com/photo.php?fbid ... 000&type=3

[JP!]

To make this model M keyboard usable as a daily driver, you could certainly substitute a replacement top and bottom case assembly from https://www.clickykeyboards.com/product ... -4-screws/ or find other sources on ebay.

I'm with you this one, just substitute a replacement case. At this point I think this board is too interesting and unique to mess with. I'd of course want a square badge like a 1390131 and finding just the case alone is pretty impossible since you'd more than likely end up with an entire separate keyboard worthy of it's own restoration and use for generations to come.

My notes so far:

• The smaller cutout of the LED sticker is atypical.

• The smooth texture on the top shell surrounding the LED cutout and possibly other areas is atypical.

• The lack of reinforcement and material of the top shell is atypical (missing screw post support gussets, etc.).

• The peeling black paint/coating for a model M case is also atypical.

• The worn dye-sublimation of the lettering on the keys is something uncommon with most vintage model M keyboards (I have really only seen this issue on some Model F's).

• Missing foam supports as typically seen with the first generation of Model M's but these could have been lost at a later date.

• Different controller / PCB design. This one is longer with a slightly different design with unpopulated chips and a few subtlety different components. Likely shared PCB design with early terminal keyboard variants.

• LED assembly is atypical and also uses a nonremovable connector.

• Socketed Motorola SC81192L IC rather than soldered is atypical.

[JP!]

Another really interesting find. It seems that the controller is quite atypical for a production Model M from 1985.

1987/88 Model M Controller:

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1985 GE Model M:

IMG_8201.JPG (559.78 KiB) Viewed 8197 times

@Rocco's 1985 Model M:

What this heck is going on here? This PCB is quite a bit longer with space for a number of unpopulated components, not to mention some other subtle differences in components.

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*It seems that this controller layout was likely borrowed from early terminal models such as the IBM 1386303.

IBM Model M terminal 1386303 from 1985-06-13

*Note that J2 has a provision for the LED cable. Evidently this disappears on later terminal controllers, likely as the Model M for the PC gets it's own dedicated controller.




'87-made 1386303

2024-02-05 16_54_21-IBM 3161 Terminal & Model M 1386303, the original enhanced keyboard - deskthorit.jpg (243.28 KiB) Viewed 8069 times

Besides the PCB the LED PCB and connector is different:

@Rocco's 1985 Model M:

Connector pins likely fixed / soldered to this LED daughterboard.

led.jpeg (1.78 MiB) Viewed 8143 times

1985 GE Model M:

IMG_8178.JPG (457.84 KiB) Viewed 8149 times

[sharktastica]

What this heck is going on here? This PCB is quite a bit longer with space for a number of unpopulated components, not to mention some other subtle differences in components. It seems that this controller layout was borrowed from early terminal models.

(Copying what I said on my Discord to you for this discussion) I've seen something very similar in terms of overall board layout. This is from a 1987 P/N 1390680 IBM 3163/3164 ASCII Display Station ALA Keyboard (photos from sandy):



Being a terminal keyboard, I initially thought it might be there for possible Keyboard ID purposes (ie, through a DIP switch bank on IBM 3270 family keyboards) but I found no evidence of that (and for 122-keys IBM usually opted to have an expanded right-angle pin header from the cable header, and more pins to support the 8-position switches they could have).

Sandy says this about that third Triomate (J6):

J6: Unknown , shortened to PCB GND with a metal alloy.

[rocco_16v]

@clickykeyboards, the only details I have on the provenance of this board is I acquired it from ebay (2 weeks ago) and it was shipped from Coppell, Texas. The seller is an electronics recycler and had the board listed as an NMB keyboard, so I don't think he even knew what he had. I saw the markings for the badge on the case and the stem for the missing keycap (esc is missing) and immediately recognized it as a IBM Model M.

@JP!, I'll take some measurements (W x D) of the controller so it can be documented and so you can compare. I will also add a full image of the backside of the controller.

@sharktastica, I will look at the traces on the unused pads in the controller to see if I spot something unusual or interesting. I'll also add some close-up pictures of the unused pads area as well.

For the time being I will not do any more repairs to this Model M aside from a good cleaning and screw mod (which is now done). I have yet to test it for functionality (electronics) since I don't have a cable, but that will have wait until I finish another keyboard project I had already started working on. I truly and really appreciate all the information, recommendations and education provided on this matter.

[rocco_16v]

I did some more measuring the PCB measures 205mm x 50mm (surface area).

Here are some images of the PCB area with the unused pads/holes. I have backlit the PCB (put some light behind it) so the traces can be better seen. I also added these pictures to the original album linked on the main topic as well as some extra images of the whole backside of the controller.

Component side (front) of PCB


Solder Side (back) of PCB

[JP!]

I did some more measuring the PCB measures 205mm x 50mm (surface area).

Thanks for the pictures. I have more to say about this board so stay tuned.