Connecting a Rohde & Schwarz PCA-Z1 to a PC/AT?

[SL]

Hi,

I recently bought a Rohde & Schwarz PCA-Z1 keyboard to go with an R&S instrument I have that takes a keyboard using a DIN 5 plug, and I thought it would be neat to connect this keyboard to it. I like the idea of a jogwheel and that it matches my instrument. The instrument runs MS-DOS 6.22 and uses the standard 437 code page. After a search on the net, it does not to be that simple. So I decided to join this forum to find out if it and how it can be done.

The PCA-Z1 has a 1/4" phono plug with a 3-wire connection: signal, +5V and GND. There is no clock signal, and on the keyboard controller PCB, there is no connection for one. I guess this keyboard is meant to be uni-directional going to the host but not backwards.  There is a newer R&S keyboard called the PSA-Z1 which has a native DIN 5 plug that has 101 keys, but it's bigger than I like, and I have not found one to buy yet.





Inside, the stems and caps are Cherry. There is even a double shot with clear(!) with a LED that lights up. Very nice. But unlike most Cherry's I've seen, the case is structural foam like IBM, and the top plate and PCB backing plates are both machined aluminum. If an F or M felt good, this one is just that little bit even more substantial in feel. The back is held to the front with 8 stainless screws, each having 2 washers. It really inspires a lot of confidence.



So here is a closer look at the controller and mux, an Intel 8749 and a SN74159N. There there is the encoder wheel - it feels really good and the LED's light up for up/down and left/right while holding the shift key down.






So, the question is, can anyone help me with making this work with my PC? I would like to add an external interface versus destructively modify this keyboard.

Thanks,
Steve

[Tactile]

Okay, it's been a week or so since I made myself look really stupid, so...

How about an Arduino (or teensy?) hooked up to grab each keypress, translate it, and store it in a FIFO buffer. The output would be interfaced to the AT & provide clock, etc signals to make the computer happy. The output loop would grab characters from the FIFO buffer & feed them to the AT. This is obviously in really general terms and I'm just talking out of my *** here.

There are folks here who know a lot about the Teensy controller and can probably help you more while at the same time explaining what an idiot I am.

[SL]

Hi there,

Well, that's exactly what I've been thinking. There are literally billions of keyboards out there and probably tens of thousands if not hundreds of thousands of folks who have done this. I was actually expecting that someone would have offered a kit to do this at a relatively low cost and a reasonably low learning curve.

That is exactly what I am hoping to find out from the pro's here.

Steve

[Tactile]

Here's a similar project that might give you some ideas...

https://blog.adafruit.com/2012/12/07/hack-usb-next-keyboard-with-an-arduino-micro-arduino-arduino-next/

[edit] here's a better link

https://learn.adafruit.com/usb-next-keyboard-with-arduino-micro

[SL]

Hi again,

Thanks - I've see that before. I have not built or coded an Arduino nor do I have access to the timing chart. From what i gather, most of the scan codes are 1 for 1 except for some of the unique features such as the jogwheel. So i 'm hoping for more guidance than having to tackle more than I can handle...

Steve