Opening an IBM AT

[Muirium]

Brown is live here. Black neutral. And striped green/yellow is earth. There's no rhyme or reason to them anywhere. You'd think the fancy striped one was highlighted because it's the most dangerous! Far from it.

Anyway, I'll know better than to trust diagrams over my meter. Because someone (me) is surely making a mistake.

[Muirium]

Intey-resting. I was having trouble with the Pro Micro powered AT on my desktop machine. Worked everywhere else reliably, but not the main place I wanted it! Today, I narrowed this down to using it on a hub. The (ancient 2006) Mac Pro is the only place I use one. I always plug straight into USB ports on my laptops. The AT worked fine on the hub so long as I didn't have much else drawing juice. But plug in my mouse charger and an (old) iPhone and all bets are off.

Hmpf.

Anyway, the Mini USB extender cables came over from China today, so I took the opportunity to swap out the Pro Micro for a Teensy 2 so I could use one. Did the trick. As in I've got everything hanging off that hub again and the AT is still working fine. Apparently the Pro Micro is hungry for power compared to a Teensy. Which makes sense, as my Teensy 2 powered Soarer box has never given me trouble no matter where I plug it in.

Right now I've got the Mini USB extender's female socket filed down to fit vertically in the AT's cable slot fairly nicely. But I haven't got it glued. So no pulling out the mini USB cable… yet. Seems a great upgrade to the AT, though, and I'm likely to make it permanent. What do you think?

[fohat]

Brown is live here. Black neutral. And striped green/yellow is earth. There's no rhyme or reason to them anywhere.

You might be able to trust colors when wiring household appliances, but electronic devices and particularly computers and keyboards get wired all sorts of crazy ways.

My advice: Never trust color!

[orihalcon]

IMG_0666.JPG

That's a pretty cool numberpad layout, I must say!

Definitely would look into adding ALT keys and using a Model M spacebar or split it with a Code key from a wheelwriter. I will be doing this to mine here one of these days! Just too bad they didn't put capsense pads between control and ALT. Seems like only 4704's and Unsavers have that, Though modifying an Unsaver that way would probably be considered sacrilege.

[Muirium]

Thanks. That's become one of my main keyboards, the TKL (77 key Kishsaver-like) layout is very compelling in Model F. In fact, it's one I'm missing while on holiday. I brought my HHKB but no Fs!

[Touch_It]

Thanks. That's become one of my main keyboards, the TKL (77 key Kishsaver-like) layout is very compelling in Model F. In fact, it's one I'm missing while on holiday. I brought my HHKB but no Fs!

Thats probably a mistake you only make once

[Muirium]

Well, I might not be quite as short of boards over here as all that…

A42A7703.jpg (450.75 KiB) Viewed 8772 times

These are all new to me. And the bottom one came brand new! It's the only one I've used, as I've conversion work to do. Including, thankfully, Xwhatsit's Controller:

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When you can't Model F, go straight to beam.

[scottc]

That Realforce is sublime. Exactly the board I wanted. Is there a story behind you getting it, or you just felt like one after the HHKB?

[Muirium]

There is a nice wee story, in fact. I'll tell it in the review. Still need to write about my HHKB, see, and the two boards are definitely comparable. The Realforce is 55g while my HHKB is 45g Type-S, so plenty going on there.

Glad I bought that second HHKB keyset, so I never had to handle the infamous Realforce bubble keys. HHKB caps work just peach on it. Just not the full set, of course.

[scottc]

I suspected there would be! I didn't realise that those were HHKB modifier caps. Nice. How do you find the 55g domes? I borrowed it at a friend's house and found it a little heavy initially, but it definitely grew on me.

[Muirium]

Definitely useable. I think my very first impression was "ay oop… Julle was right… sharky sharky" but that only lasted the first minute as my fingers figured out I wasn't on my HHKB any more. Since then it's been a sweet board indeed. I love the key shapes and the feel. It's a right looker, of course, too.

As I'm at my brother's, I'm using these boards hunched over my laptop, so I'll need to get them home and use them at my standing desk before I really know. Been nagging him to get a 4k desktop display to spare my back! Bugger me if I'll pay for it if it has to stay at his place…

Anyone got recommendations for 4k IPS displays with (mini) Displayport? Note the IPS and 4k, before you answer, Andy! Smaller is actually better. I want my photography to pop, instead of my back!

[Hypersphere]

@scottc, @Mu, Regarding 55g Topre, I go back and forth. One day I definitely prefer 55; other days, I like the lighter touch of 45.

The best combination for me is found in my modified HHKB: black case with Topre silencing rings and transplanted 55g domes. I also like a different color scheme from the standard options -- the alphanumeric keys are blue with black legends, the mods and spacebar are blank black, and the Esc and Fn are red. This has become my favorite board, at least for now. I really like the sound and feel that is achieved by combining silencing with the somewhat heavier domes.

I also like my RF87u boards, but after using the HHKB and V60 for some time, I am finding it harder and harder to adjust to anything larger than a 60%.

No recommendations for 4k or 5k displays. It will be some time before I can afford to upgrade monitors -- I have 3 workstations, each with with 3 monitors. Each station has a 27-inch 2560x1440 and two 24-inch 1920x1200 displays. I am content with these resolutions, and so I don't even want to look at a 4k or 5k display, because I know I would then have to upgrade all of the monitors.

[Muirium]

My display at home is an ancient and positively crappy 1680x1050 20" Dell. Dim as my old PowerBook, and just as waxy. It was playing dead the last day I was there. If Apple came out with a new Thunderbolt (or USB C!) display I would read that as a sign. But looks like I'm just plain buggered!

I've got a 55g Realforce TKL over here, as well as my travel HHKB, so I'm noting impressions. Besides the very first moment that I tried it, 55g doesn't feel that compellingly different to me. The Realforce is a pretty board, and feels excellent in its own right, but the HHKB is nigh impossible to beat.

[Ludovician]

So guys, I partially disassembled my AT yesterday (I appreciate the encouragement about taking off the case initially, that thing really sounded and felt like it was going to break), and not sure what I need to do to disassemble the inner assembly. I see that bent tab on the end, and I think someone mentioned that you need to bend that out of the way with pliers?

I just want confirmation that that's what I need to do, because I really don't want to damage this board. Won't be able to find it at that price again, most likely.

Also, is there anything that is likely to cause problems during reassembly?

Thanks.

[Muirium]

I vaguely remember detailed guides about opening up Model F assemblies. Perhaps someone has a good link. If you're worried, you're best to wait until one shows up!

It's not really a dangerous process though. I've done it several times now to two Model Fs: my AT and my even more valuable Kishsaver. You're basically just sliding the back metal plate to the side a little bit, where it comes free from the hooks you can see coming down from the barrel plate. You're unlikely to harm it. But the springs could get a bit angry. Especially during reassembly. And *especially* on the spacebar on an AT!

So yeah, anyone got a video?

[Khers]

I found this guide by JBert very helpful when I was disassembling, cleaning and reassembling my Bigfoot. No video, but rather detailed nonetheless...

[fohat]

I see that bent tab on the end, and I think someone mentioned that you need to bend that out of the way with pliers?

Bend the tab upright, just like the others.

The parts are in a "sliding force fit" so you will have to stand it on one end of the longer plate, and gently tap the shorter plate with a hammer until the "inner" tab slides out of the "mouth" of the larger tab.

At that point, the plates will fall apart and the barrels and springs will spill out on the table.

"Reversing the procedure" to re-assemble is the hard part!

3 rules: (1) use clamps (2) use clamps (3) use clamps

[Muirium]

For what it's worth: I never needed a hammer for either of my Model Fs. I found them pretty easy to slide open with my hands. This likely varies between keyboards, of course. Especially up at the big end with 122 key Model Fs. My AT felt very similar to my little 62 key Kishsaver though.

Oh yeah, I didn't use clamps either. Again, there wasn't anything to fight against. My jig was simply two big books to hold the barrel frame upside down from the edges. Everything else done by hand.


http://deskthority.net/post209092.html#p209092

But look out for that spacebar! JBert's guide helps get that captured spring to stay still while reassembling.

[JBert]

@µ - The ATs don't need too much tools, though the clamps are seriously handy to keep your hands free (pun intended).

You can't do without clamps for an XT though, they're even tougher buggers!

[Ludovician]

Will the spacebar still be an issue if I intend to do the Model M spacebar mod?

[Muirium]

Somewhere along the line, I forgot to update how this AT went. Good news: fully functioning, feeling fine, and a very handsome board if I dare say so myself! I pulled it down from the µseum shelves earlier, somehow having forgotten I'd finished the project a while ago. No dodgy Pro Micro, and no silly fixed cable any more: this AT has a mini-USB socket installed right where the chunky AT cord once came out. The shape of the case is just wide enough to slip a Mini USB cable straight in there, as if designed for the future task.

Having been on my Kishsaver for a couple of solid weeks, I can compare these boards directly. The Kishy is obviously smaller, more imposing, and cold to the touch; thanks to its solid metal shell. The Kish also has a better, very almost straight up HHKB layout. But this AT isn't so far behind. The sneaky cursor keys mod I did in the numpad opens it up as something of a TKL. The Model F feel is all there, right across the board, and then there's that spacebar. Goodness me, is it heavy! And huge. Ultimately, I'd like to follow JBert's lead and swap it out for a Model M spacebar with a couple of much-needed mods. But, saying that, I must admit it's chock full of character the way it is now. My old XT muscle memory is keeping me mostly on track, while the Kishsaver and HHKB cues on the top right make it feel very much like home. I could well use this one the whole time if I chose to.

ATs are great boards. Even if you haven't an AT socket anywhere in sight, they still beat the XT in my view, for sheer customisability and downright sanity in the layout. The caps are great, the dyesub rich, and the feel is classic Model F through and through. A Deskthority essential keyboard, in my view. Everyone must have one, if they have the chance.

[Engicoder]

Glad you are enjoying your AT. They are definitely more flexible in configuration than the PC/XT and as you mentioned can emulate a TKL very well. My one beef with the AT is the case. It still gives me the willy's every time I have to open one up. That creaking/cracking noise and feeling is frightening. I much prefer the simple method used on the XT.

[fohat]

It still gives me the willy's every time I have to open one up. That creaking/cracking noise and feeling is frightening. I much prefer the simple method used on the XT.

Roger that. Why is this the only F lacking a metal bottom pan?

[chzel]

Because it was the last F before IBM cheaped out?

[bhtooefr]

There's another F with a plastic bottom, the 5155 - the XT Superleggera. Aluminum plates for the internals, and plastic bottom instead of steel plate. Which, that was the first keyboard for which IBM had figured out plastics to the point that they really trusted them, and it was very shortly before the 5170...

[Wodan]

Thanks Nuum. That gave me the confidence to keep going, and finally I'm in. The technique? "Gie it laldy, son!" Translation: with great force.

No harm done. It really is a tough bastard. Nice!

I'm still stumped by the spacebar though. One of its two stabs is still hooked in, and no amount of wiggling seems to convince it to come free. Bugger!

Just cracked my first IBM AT open and had the same concerns as good ol µ here ...

Thanks to the info from this thread, I just went in there like Rocco

[Muirium]

Kmnov messaged me to ask about (their missing) AT cable's pinout. I don't know where I put mine (it was in a sticky state) so I cracked open my AT to take a couple of pics of my hacky Teensy job, done a few years ago. Yes, prepare yourselves for some charred solder work! Not my finest job, but it's held up.

First, here's the underside of the controller. I simply hooked into the cable's pins individually, from below:

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And here's where my four connections meet my Teensy, usually tucked into the space above the LED PCB, but pulled out here to take a look:

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As we all know, PD0 is data and PD1 is clock. So the colours are:

• GND = grey
• V++ = red
• DAT = yellow
• CLK = blue

Because Soarer's converter's tools (scas, scwr, etc.) are 32 bit, they're incompatible with Mac OS Catalina. That's not a huge problem, but I do like to play around with layers from time to time, so I'm tempted to do a better job installing an Xwhatsit Controller PCB I have spare anyway. But this setup, and these wires, works for sure.

Oh, one more thing: originally, I installed a Pro Micro. Didn't work. The AT seems to be too much power draw for the wee Arduino. But a Teensy handles it.

[Muirium]

As threatened, I whipped out the original controller, and my Teensy, and have my AT running on Xwhatsit now. Must say I do love his controller software! It's a joy to use a GUI for this kind of matrix work. Here's what that looks like, now I'm all set up:

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An extra bonus is I can use this keyboard with the iPad now it's lost its power draining IBM controller. Nice to have the AT up at Kishsaver level functionality after all these years!

Actually, one thing I forgot was the LEDs. As Xwhatsit says in his manual, IBM's cable needs some rearranging to work. That'll be my next project inside this auld beastie.

You know, before I get ideas about finally doing the spacebar mod.

[Muirium]

Actually, here's some cunningness I'd like to share, entirely in the GUI.

I like to have Control on the key left of A. Caps Lock is one of those keys I seldom use, but when I do want it, I have it tucked away in a super obvious macro: Shift + Shift = Caps Lock. Done that for years. I'm not kidding when I say I rarely use it: I only just noticed it wasn't working any more when I fixed up this AT! Plugging in my Kishsaver, I found it wasn't working any more there, either!

Caps Lock worked fine when I use it HHKB style: Fn + Tab = Caps Lock. And any other key was working fine as a macro on Shift + Shift. Only the combination was upfucked! It wasn't even a matter of needing to clear Shift inside the macro, as when I did that, it still didn't work; while Shift + Fn + Tab was still working fine. Gah!

After much experimentation, tea, swearing and head scratching, I figured out what was up. It's a timing issue. The Mac treats Caps Lock differently to other keys. Likely a safety measure against WHAT MY KEYBOARD BORKEN11 mishaps from people who, understandably, hit the damn thing inadvertently. Caps Lock needs to be pressed some arbitrary length of time. Fast enough that I don't notice it in practice, but slow enough that Xwhatsit's macros broke. They press and release keys too quickly. And there's no obvious way to slow them down; with no MAKE or BREAK options, only combined PRESS.

So what did I do? This:

Screenshot 2019-09-27 at 2.44.55 pm.png (274.94 KiB) Viewed 7568 times

Wot? No Caps Lock?

Yeah, I was crafty. What the macro does now is kick the keyboard into another layer for 0.2 seconds. While you're there, I remapped both Shift keys to Caps Lock. So what the keyboard sees is Shift + Shift turns into Caps Lock for 200 milliseconds, then back again. I made the original input into Caps Lock instead, so I could take my time and clear the OS's filter.

There are (and always were) two macros, actually. Left and Right Shift each have their own, to handle both available sequences of Shifts. The keyboard certainly knows which one you pressed first, even if it doesn't matter for our purposes. I learned that trick, along with the Shift + Shift macro itself, straight from Soarer.

So there you have it. BREATHE EASY NOW, YOU CAN SHOUT AGAIN! And toggle it off all elegant, like. Where there's programmability, there's a way.

Oh, one last thing. Xwhatsit's GUI has always doubled up controllers on the Mac. I told him about this back when I was his guinea pig with the Kishsaver. Now I've got two Model Fs running his controller, this is what the GUI presents me with on launch, when they're both plugged in:



Those strings vary every time. And two of them are booby traps, which will hang the GUI and make me Force Quit and try again. There's no logic to their pattern that I know. But it is amusing to see them stacking up with more hardware.

No, I've only got 2 Xwhatsit powered Model Fs really…