Model M: The contacts under the 0, Enter, and + numpad keys

[E TwentyNine]

On on Model M standard US ANSI layout, the shift keys and backspace cover two barrels and there's a contact under the unused one that will generate a scancode when pressed, used for other key layouts. 

However, the 0, Enter, and + key on the numpad have the same setup, and there's contacts beneath the second barrels here as well, but pressing them does not generate a scancode (on the M I'm currently tinkering with).

Are there certain versions of M controllers where it does generate a code?

[fohat.digs]

It was my understanding that all of the "secret keys" were available, but I am not an expert in electronics.

Are you using hid_listen or something similar to know whether a scan code is generated, or is it possible that something is being generated but simply not recognized or understood?

[E TwentyNine]

Using Aqua.  Just a standard M.  The unused contacts under shift/bksp register codes but show no key highlight.

The ones in the numpad don't.

There was a thread about the numpad keys not too long ago, but my search fu is failing me.  I don't recall what the outcome of that thread was.

[TheRavenDog]

There are 5 secret keys on most Model M keyboards.

Left Shift: ScanCode 0056
Right Shift: SC0073
NumPad Enter: SC0078
NumPad Plus: SC007E
Backspace: SC007D

The barrel under the NumPad Zero doesn't generate a scancode on most Model M keyboards. I don't even think there are membrane traces under the NumPad Zero (but I can't remember for sure: it's been a while since I bolt-modded a Model M).

There's also a barrel under the left side of the space bar (but I'm almost sure there are no membrane traces). I think it's just there for stabilizing.

Finding key caps for the extra keys is pretty easy, expect for the right shift key.
   - The Backspace converts to two standard keys. Easy.
   - The Left shift converts to the small left shift (found on most international and PC122 keyboards) and a normal keycap. Moderate.
   - The right shift converts to a normal keycap and a very specialized shift key (found on old Portuguese Model M, but still available from Unicomp). The CapsLock keycap is close. Hard.
   - The NumPad Plus converts to two normal keycaps. Easy.

When used in conjunction with AutoHotKeys, the extra keys next to the shift keys make nice additional modifiers (I use mine for combining diacritical marks, and as a Command Key.)

[dorkvader]

There are 5 secret keys on most Model M keyboards.

Left Shift: ScanCode 0056
Right Shift: SC0073
NumPad Enter: SC0078
NumPad Plus: SC007E
Backspace: SC007D

The barrel under the NumPad Zero doesn't generate a scancode on most Model M keyboards. I don't even think there are membrane traces under the NumPad Zero (but I can't remember for sure: it's been a while since I bolt-modded a Model M).

There's also a barrel under the left side of the space bar (but I'm almost sure there are no membrane traces). I think it's just there for stabilizing.

Here's a picture of my 1390120 plate and membrane, for refrence:
http://i.imm.io/13joS.jpeg

I don't know if the controller will output a scancode, but the numpad 0 does have traces. (I think they might go to 13,1 but I could have looked at it wrong)
As you can see, the extra spacebar barrel has no trace.

[E TwentyNine]

Ok, I found the old thread, same info there.

But I am definitely not seeing any scancode with the Numpad + and Enter secondaries.

EDIT:  It's the bluecube stopping the scans from being seen.  Switched to an old cheapo ps/2 keyboard/mouse to USB adapter and the codes come through.

Don't know why it would pick these particular codes to filter.

[Soarer]

Just because some are more standard than others. For example the one under left shift is used on ISO layouts, and some of the others on other layouts. I can't think of a standard layout that splits numpad enter though!

Blue Cube does better than most adapters; quite a few don't even handle ISO 

[E TwentyNine]

I've seen terminal keyboards that split the num top right key:



guessing there's some out there that split the lower right key as well.  Or maybe IBM was just leaving it open for future customization.

[mich]

USB and PS/2 use different scancodes. Blue cube apparently has no idea how to translate PS/2 scancodes from these phantom keys and ignores them.

[Soarer]

OK, I should've said standard PC layout.... since that's what the adapters are trying to tackle.

Brazilian splits the numpad '+'...

[berserkfan]

Hey can I ask how to put the secret keys into use?

1)   I don’t see any springs inside. Should I buy the springs from Unicomp?
2)   Let’s say I buy the springs and put them inside. Is it sufficient to generate a signal just by plopping a keycap on top and pushing down? Or do I need to take apart the Model M and fix the spring to the board somehow?
3)   That done, how do I know how to find the scancode?
4)   And what does a scancode do? My very superficial knowledge of Autohotkey says that it doesn’t use scancodes. It's not as if I can just put in scancode1::dothisandthat

I am just your average idiot, sorry about that!

[Soarer]

You'd need to 'bolt mod' the model M to put new springs and hammers in. Autohotkey can report and deal with scancodes - you can put something like: SC034::Send {Blind}{SC053}

One caveat that I don't think has been mentioned in this thread is that the 'extra' pad under the ANSI Enter in the main block sends the same code as the backslash key (for 101- or 102-key boards). It's used for the ISO layout. Only an issue if you want to reduce your Enter key to 1.25 units in size!!!

[berserkfan]

wow...

you guys are really hardcore enthusiasts...

it's quite a project to do bolt modding.

oh well, having said such things, I do suspect that in a year's time I will get around to doing bolt modding! And its all thanks to having you guys being the role models!

After all, when I first started, autohotkey was off limits (involved programming). But now I am eagerly digging into it and looking into the possibility of creating my own ghetto greens and reds (see another thread)...

[fohat.digs]

Funny. Bolt-modding is a bit tedious but not that big of a deal.

But I guess that I am just a lot more comfortable with a drill than with a soldering iron.

[nrichers]

The barrel under the NumPad Zero doesn't generate a scancode on most Model M keyboards.

This is an ancient thread, but I stumbled on it trying to solve this very same thing. I have a 1993 terminal Model M (1394204) and added the extra key for the numpad zero to the board but couldn't initially figure out how to get it to work with Soarer's.

QMK Toolbox helps and showed the key scan code for the extra numpad zero key to be +B6, which is 0xB6 or EXTRA_INSERT as per Soarer's documentation. Mapping that to another key like F13 works just fine.

Posting this here on the off chance that it helps someone else a few years from now.