IBM Electronic Typewriter Model 95 - Capacitive Buckling Springs

emdude · 03 Jun 2017, 05:05

Thanks to ohaimark, I recently learned about the IBM Electronic Typewriter line, an obscure typewriter that sat between the Selectric and Wheelwriter typewriter lines and was a hybrid of both, with electronic internals and a Selectric element ball. The only reference I could find to them on DT was in the opening paragraph of the wiki entry on the Model F.

According this site, the later 65/85/95 models were introduced in 1982 (although I believe this is from 1983 or later, see the photos of the typewriter controller below). After watching a video of a disassembly of one, I had a hunch they had capacitive buckling springs; after some eBay snooping I was able to land a Model 95 keyboard assembly for a reasonable price:

I was happy to see it was definitely a Model F! I hope I can get it converted. Some interesting features of the keyboard:

Plastic barrel frame with melted rivets, predating the Model M!
Latching Caps Lock
Slip-on controller
Rubber O-Rings on most barrels, like some Wheelwriters
Stepped, unstabilized wide keys

Keyboard:

: IBM 95 -- Keyboard w/ chassis; 22.png (2.84 MiB) Viewed 14699 times

: IBM 95 -- Chassis close-up; 21.png (2.81 MiB) Viewed 14699 times

: IBM 95 -- Assembly sandwich; 20.png (2.67 MiB) Viewed 14699 times

: IBM 95 -- Keyboard w/ chassis removed; 0.png (2.87 MiB) Viewed 14699 times

: IBM 95 -- Keyboard bottom w/ thick rubber mat over backplate; 1.png (3.06 MiB) Viewed 14699 times

: IBM 95 -- Label; 32.png (2.86 MiB) Viewed 14699 times

Keyboard Controller:

: IBM 95 -- PCB Pinout, 24 pins, 16x4 matrix; 2.png (2.95 MiB) Viewed 14699 times

: IBM 95 -- Keyboard controller; 5.png (2.97 MiB) Viewed 14699 times

: IBM 95 -- Keyboard controller close-up; 6.png (2.69 MiB) Viewed 14699 times

: IBM 95 -- Keyboard controller close-up; 7.png (2.7 MiB) Viewed 14699 times

Keys:

: IBM 95 -- Wide keys; 11.png (2.87 MiB) Viewed 14699 times

: IBM 95 -- Wide key barrels; 12.png (2.63 MiB) Viewed 14699 times

: IBM 95 -- Latching Caps Lock key; 13.png (2.64 MiB) Viewed 14699 times

: IBM 95 -- Comparison of A key (left to right): IBM 95, IBM Model M 1390120, Custom Unicomp SSK keyset; 17.png (2.63 MiB) Viewed 14699 times

: IBM 95 -- Comparison of W key (left to right): IBM 95, IBM Model M 1390120, Custom Unicomp SSK keyset; 16.png (2.79 MiB) Viewed 14699 times

: IBM 95 -- Comparison of key bottoms (Left to right): IBM Model M 1390120, IBM 95. The sprue for the 95's keycaps is underneath the cap and not on the back.; 18.png (2.74 MiB) Viewed 14699 times

: IBM 95 -- O-Ring; 10.png (2.68 MiB) Viewed 14699 times

Misc:

Spoiler:

Typing and Caps Lock Demonstrations:

hypkx · 03 Jun 2017, 09:59

Thanks for the pictures, very interesting post and awesome find. #DTA7

//gainsborough · 03 Jun 2017, 10:04

This thing is really neat - it would be very cool if you could convert it somehow!

You should do a typing demo =)

Nuum · 03 Jun 2017, 10:39

Nice one! How does the latching caps lock work? Is the long on/off button a buckling spring toggle key of some kind?

arkanoid · 03 Jun 2017, 12:29

Another buckling mini layout keyboard! Thanks for the photos.

emdude · 03 Jun 2017, 20:51

Thanks guys.

@Gains, if I can find time to record one this weekend, I'd like to!

@Nuum, the Caps Lock works like one on a manual typewriter, after toggling it, it's released by pressing either Shift key.

emdude · 04 Jun 2017, 00:34

Updated the OP with a brief typing video and a demonstration of the latching Caps Lock!

Apologies for the poor sound quality!

ideus · 04 Jun 2017, 01:20

Wow! the typing sound is really impressive. Thank you for the videos.

//gainsborough · 04 Jun 2017, 01:41

emdude wrote: Updated the OP with a brief typing video and a demonstration of the latching Caps Lock!

Apologies for the poor sound quality!

Thanks for the typing vid, dude! It sounds really neat!

XMIT · 04 Jun 2017, 04:01

Wow, that's incredible. Does the typewriter itself work? I imagine it takes a third generation Selectric ball...

Findecanor · 04 Jun 2017, 04:10

Hmm... What was the reason that IBM did not choose to use the latching mechanism for the IBM PC?
Are the Shift keys harder to press when the Caps Lock key is down?

emdude · 04 Jun 2017, 04:26

XMIT wrote: Wow, that's incredible. Does the typewriter itself work? I imagine it takes a third generation Selectric ball...

I only got the keyboard assembly with a few other things, but its seller noted that the typewriter did not seem to function. The typewriter does take a 96-character element ball, like the Selectric III.

Findecanor wrote: Hmm... What was the reason that IBM did not choose to use the latching mechanism for the IBM PC?
Are the Shift keys harder to press when the Caps Lock key is down?

Only slightly, the spring holding the lever up is very light.

Spoiler:

daedalus · 05 Jun 2017, 22:18

Extraordinarily nice find. I think this is the first example of a buckling spring keyboard with a locking Caps Lock which I've seen too.

Darkshado · 06 Jun 2017, 04:49

What's the reasoning behind o-rings and why have they disappeared since?

ohaimark · 06 Jun 2017, 13:50

Probably to prevent bottom out (though I can't say for sure). I've noticed that AT keycap stems will deform at the base if bottomed out heavily on a regular basis. That can result in them catching on springs.

alh84001 · 27 Sep 2017, 19:35

Here it is with xwhatsit's controller (emdude was kind enough to pass this little beauty on to me):

I desoldered the header from original controller and soldered it to xwhatsit's. Mapping of the pins (when viewing keyboard/PCB from above is):

Code: Select all

G R4 R3 R2 R1 G C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 G G

This is slightly different from xwhatsit's pinout, so I bent leftmost G and R1, and added a jumper wire from R1 to a row pin on xwhatsit.

Next up, there are two additional pads on the right side of spacebar. When 5.25U spacebar is used instead of original one, that leaves space for a right shift key to be put up there. It's either that or two 1U keys, at least until ellipse produces split right shift pack for his kishy replica project.

Two positions on the left side of spacebar don't have contact pads unfortunately.

(Attached is my xwhatsit config file (base layer only), for archiving purposes)

0100010 · 27 Sep 2017, 20:06

Only the second time I have seen a Model M / F with orings around the barrels. One of these days I'll get around to adding some to my boards to check for sound affect.

0100010 · 27 Sep 2017, 20:09

Darkshado wrote: What's the reasoning behind o-rings and why have they disappeared since?

I don't think the orings do anything with bottoming out, only area you can place something that will effect that would be on the top of the barrel. I think they are only for changing the buckling sound response.

Edit : adding image

alh84001 · 27 Sep 2017, 20:22

Yeah, sound is definitely different. Less ping reverb or something similar. It's maybe a little less loud as well, but still quite loud though. Note that this is an F PCB in M assembly, and probably only louder BS board I have heard is i$'s FSSK, which is in a league of its own.

2ter · 28 Sep 2017, 00:00

0100010 wrote:
Darkshado wrote: What's the reasoning behind o-rings and why have they disappeared since?
I don't think the orings do anything with bottoming out, only area you can place something that will effect that would be on the top of the barrel. I think they are only for changing the buckling sound response.

Edit : adding image

this gif omits the little reinforcements on which the o-rings sit. i think o-rings do soften the bottom out. they don't really influence the sound, at least on a model m. only the floss mod, dry lube and similar mods on the spring and/or the inside of the barrels can get rid of the ping and ringing.

JP! · 13 Oct 2017, 15:53

Nice work on this with the Xwhatsit. Now we just need a custom case for this.

Chyros · 13 Oct 2017, 16:32

I had one of these a while ago, it was extremely filthy and kind of falling apart. If I had known this model wasn't really known I'd have done more to clean it up and document it xD . Yours is much nicer though

.

alh84001 · 15 Nov 2017, 20:25

Yeah, it's quite rare. People over on http://www.ibmtypewriters.com/ don't have one for instance.

How can you pass up a model F, whatever the condition is?! If anything, springs and flippers are useful to all of us here

purdobol · 15 Nov 2017, 21:06

Very nice find indeed. Hehe yet another typewriter added to watchlist.

DustGod · 20 Nov 2017, 23:43

Ah, latching switches on buckling springs! That's awesome!

Karmel · 09 Jun 2020, 20:46

There is also an IBM selectric that used beamspring switches, it was the first word processor I believe. This also means that every generation of IBM mechanical switches can also be found in typewriters.