IBM/Toshiba Model M7 POS Keypads

[sharktastica]

Yeah, I know these are not the most glamourous things in the world, but I thought it might be of interest for some.

IMG_20200509_230108188.jpg (1.83 MiB) Viewed 5594 times

I'm working on converting two of these keypads into macropads - one for home and one for my university office I'm allowed back - with the ultimate goal of making turning the keyhole turn the host PC on and off. I mean, how cool would that be? Anyway, earlier in the week, I took some photos when I was digging inside the one dead one I have to see what's what and decided to share them in case they are interest or useful for anybody. I've also made some commentary too.

41J7248_box_open.JPG (262.51 KiB) Viewed 5594 times

The M7 in question is the only one out of the three that's effectively dead. P/N 41J7248.

41J7248_keycaps.JPG (256.13 KiB) Viewed 5594 times

M7s have two types of keycaps; 1-unit stems with either a 1-unit or 2-unit keycaps on top, or 1.25-unit stems with transparent keycaps on top. Not using a bar or rod stabiliser approach that traditional Model Ms used, the numeric zero key simply uses a second redundant stem for stabilisation.

41J7248_logo.JPG (318.5 KiB) Viewed 5594 times

Not being a consumer product, branding is tame on the M7s, with only a single IBM oval on the back wall.

41J7248_sdl.jpg (245.99 KiB) Viewed 5594 times

M7s use what is seemingly a variant of the shielded data link (SDL) connector traditional older-generation Model Ms famously use. Compared to a standard SDL socket, this socket is overall wider and it is a very tight fit if you try and ram a standard SDL cable in there. It can get stuck, so don't try that at home. You have officially been warned! Besides, even if it did fit, it wouldn't do much as the M7 speaks RS485 serial, something no average home PC supports natively.

41J7248_mount.JPG (377.13 KiB) Viewed 5594 times

41J7248_screws.JPG (397.05 KiB) Viewed 5594 times

One aspect M7s thankfully don't share with their more infamous brethren is that they are held together with just three Phillips screws instead of four 5.5mm nuts.

41J7248_opened.jpg (308.06 KiB) Viewed 5594 times

41J7248_backplate.JPG (276.04 KiB) Viewed 5594 times

Guess the assembly is screw-modded for you, eh.

The keyboard assembly is a sandwiched just like a Quiet Touch M, with domes on top, followed by two layers of membrane, and backed by a thin plate of metal. I didn't open it on this occasion since I need this assembly intact and didn't want to take additional risk. The black coloured assembly on top of the plastic ridge is the magnetic strip reader (MSR).

41J7248_mainboard.JPG (435.07 KiB) Viewed 5594 times

41J7248_mainboard_closeup.JPG (402.45 KiB) Viewed 5594 times

41J7248_ribbons.JPG (405.41 KiB) Viewed 5594 times

Perhaps the most interesting revelation for me is that the way the membrane connects to the mainboard is the same as how it is done on a traditional Model M. The type of connector is a Triomate, which is commercially available and means hooking the assembly up to a breadboard is super easy.

41J7248_ribbon_socket.JPG (459.17 KiB) Viewed 5594 times

Specifically, the Triomate I'm holding is a 6-520315-6.

[youtube]https://youtu.be/yuB3bfj6JIA[/youtube]
If you want to know how it sounds. You can tell it's an IBM product (ie, they're quite loud). As for key feel, they're not really mushy like you might expect. Their action feels very sharp, with the keys instantly descending to bottom once you apply force. They're heavy enough that you can't actuate them by resting on them, though.

Anyway, I'll post updates once I've got some process on my mod. Enjoy!

[Redmaus]

Interesting, you could make that keyswitch the on off button for your computer. Would def make a great macropad.

[Muirium]

If you turn the key to the off position (according to your planned mod) does the computer throw a shutdown dialog, straight shutdown, or hard power off? Just wondering on the intended implementation! There’s a range of user experiences available.

As for the macro pad: got plans for the macros themselves? I just don’t think that way. My tricks are all fired from regular key chords—not even function keys—or I’ll just forget them.

[sharktastica]

If you turn the key to the off position (according to your planned mod) does the computer throw a shutdown dialog, straight shutdown, or hard power off? Just wondering on the intended implementation! There’s a range of user experiences available.

I'm leaning towards straight shutdown. I like the idea of a simple no-nonsense shutdown I can trigger with the key as I leave my room/office.

As for the macro pad: got plans for the macros themselves? I just don’t think that way. My tricks are all fired from regular key chords—not even function keys—or I’ll just forget them.

The scenarios will be different for the two locations. At home, my plans for it are quite fluid, but most likely coding-related shortcuts. Thought about gaming ones too, but I don't see the advantage of having a separate board for those (in that case, I would prefer my macros to be on regular keys like you, otherwise you're just moving your hand away from the main keyboard a lot). In my office, I'm definitely leaning towards having them bring up stuff my various email accounts, GitHub repos, and important forms like timesheets, progress report templates, and expenses claims.

[Muirium]

Ah, those sound very useful functions. The hard part may be in scripting them. To state the obvious, yet essential: you want the macro pad to be able to trigger the action no matter what app is in the foreground on your screen. I trust you have a cunning plan!

(For what it’s worth, mine come in many shapes and forms, and the most convoluted run via this system wide scripting utility.)

[sharktastica]

Aye. I'm hoping that I can adapt the Wheelwriter conversion mod for it, allowing me to use a Soarer's directly on the matrix and bypass the RS485 serial components. But failing that, I have a few other things in mind. Besides, it will be a while until I'm allowed back at my office, so I've got a while until absolutely needing this.

[Sturmtiger001]

I always wanted to get one of these things and after watching your video on the sound of them, I think I might just get one after all.

[sharktastica]

I always wanted to get one of these things and after watching your video on the sound of them, I think I might just get one after all.

Awesome!

[Tbernstein2368]

We’re you able to convert the RS485 to something that a PC can use? Also what cable were you able to use from the keyboard to the pc or converter? I’ve got a few NOS 4683 keyboards id love to convert but despite searching I’ve not been able to find anyone else whose been able to do it