can I make an AT to Ps/2 adapter?

[Voixdelion]

Huzzah! Recently found a model F in the room full of stuff that has yet to be sorted out since granddad passed.   Its in great shape (although that's not surprising given its tank-like  construction) and I know it hasn't been subjected to much duress.  The boyfriend, who was recently rummaging about in there, says he saw more than one of these, but I'm not sure if he is referring to my stash of recently acquired M's since he wouldn't likely know the difference at a glance, however, there IS evidence that there may be at least one more lurking  about since there are several black cords with the 5-pin DIN that I  found in the garage, presumably from additional boards as this one was  sans cord in the room.  

Like imav, I too was intrigued by the recording here.  Initial 'dry  typing' on the keys confirms that extra bit of "ping" as compared to the  M and I am dying to give it a spin for real.  I have a cheap-o ebay adapter coming from china, but just can't wait.  Is it possible to make my own out of unused 5 pin and 6 pin cables by cutting off the respective ends as necessary and splicing wires together or is there some kind of capacitor/resistor/circuitry necessary for proper signaling?

[ch_123]

AT and PS/2 are the same thing with different connectors.

If you look up kbdbabel, you'll find pinouts for the two.

In fact, you could open up the Model F and wire a PS/2 cable directly to the contacts on it. The AT cable is removable on the inside, so you can do this non destructively.

[Voixdelion]

Excellent!  I was actually looking at acquiring a model F as my first mech board  because of the capacitive switches but was deterred by the connection being the 5 pin DIN and didn't want to spend money on something that mightn't work since I didn't know anything about that.  Not that it would have saved me any trouble at the time since I only just discovered the F last week-ish despite it being under my nose the entire 5 years I've been here in the same house with it.  I imagine using it will feel a bit like coming home.  

Sure is a HEAVY bugger, tho...

[bhtooefr]

Is that an AT or an XT Model F?

AT has a separated numpad and an L-shaped enter, XT has a wide vertical enter and the numpad is part of the same area as the main keyboard.

An XT Model F will require a protocol converter, an AT Model F will just require a pin adapter.

And, $5 can get you an adapter to go from AT to PS/2, even from a brick and mortar store like Micro Center or Fry's (depending on what's available in your area.) XT to PS/2 is significantly more expensive, and is usually only available from sites selling keyboard accessories.

[bhtooefr]

Wait, that looks like what would come with a Model M PS/2 to adapt it to AT - note the male AT end.

[bhtooefr]

IIRC, mine actually has a cable, so the larger AT plug doesn't interfere with ports nearby. (But it's not metal.)

[itlnstln]

So yours is long and floppy?

[Voixdelion]

Uh-oh.

"Houston, we have a problem..."

Well, the enter key IS vertical, but isn't wide.  It's the same width as a single key but two rows tall and the num pad is right next to the main keys as well.  No identifying info on the outer casing (metal) but a logo in the upper left that says "IBM Personal Computer" and the innards reveal the following label:

IBM Model F
PT No. 4584656
EC No. 998739
Shop Date K5 4904

There is a 5 pin (male) connector at the end of a black spiral cord which apparently houses 4 wires (brown, red, grey?, black).  They are the only four contacts in a plastic piece with space for 14 pins which is held by a blue clip on the circuit board.  There are 10 pins coming off the board which align with the middle 10 holes on the plug but only four actually contact with the aforementioned wires.  



Ah, now I see the subtle difference in the logo on the pics - thanks ripster

 It is as the first, unfortunately.   Exactly what am I looking at here?  Do i need to get a project box from  Radio Shack or what?

[Voixdelion]

So yours is long and floppy?

(giggle)

And ripster, just what do you know about my BF's dongle, eh?

[itlnstln]

I'll show you mine if you show me yours.



This is the type that came with my Northgate.

[ch_123]

Uh-oh.

"Houston, we have a problem..."

Well, the enter key IS vertical, but isn't wide.  It's the same width as a single key but two rows tall and the num pad is right next to the main keys as well.  No identifying info on the outer casing (metal) but a logo in the upper left that says "IBM Personal Computer" and the innards reveal the following label:

IBM Model F
PT No. 4584656
EC No. 998739
Shop Date K5 4904

There is a 5 pin (male) connector at the end of a black spiral cord which apparently houses 4 wires (brown, red, grey?, black).  They are the only four contacts in a plastic piece with space for 14 pins which is held by a blue clip on the circuit board.  There are 10 pins coming off the board which align with the middle 10 holes on the plug but only four actually contact with the aforementioned wires.  



Ah, now I see the subtle difference in the logo on the pics - thanks ripster

 It is as the first, unfortunately.   Exactly what am I looking at here?  Do i need to get a project box from  Radio Shack or what?

You're dealing with the more common, but non-AT/PS2 compatible XT model.

You will need an adapter for them. These adapters are usually home made, and when people sell them, they sell for far more than the keyboard is worth... If you have experience with assembling electronic circuits, then you might want to read up about it. Else you'd be better off getting an AT model.

[bhtooefr]

That adapter is the kind that I went out and bought.

The protocol translator will use a microcontroller of some kind, as it will have to decode the data coming from the XT keyboard and from the AT/PS/2/compatible machine, and encode data to go to the new machine.

[kishy]

I've always found (ugh, here we go...) that the stubby adapters tend to loosen up the PS/2 ports (that is, when plugging AT into PS/2).

The ones which have a short length of flexible cable seem better because the leverage effect from the weight of the cord pulling down is reduced...or something like that.