Is there any mod to connect externally an A1200 keyboard?

[guybrush]

I know I can use PS2 and USB keyboards with the A1200, but I could not find much related to use a ribbon A1200 keyboard as external, instead of internal.


Basically something similar to a checkmate case, but just for the keyboard.


Did anyone ever made a kit for this purpose? Thanks

[Jope]

Micronik sold a kit, but it isn't very good, no NKRO.

If you get a ratty A500 keyboard (mitsumi type), you can use its controller board on the end of the A1200 keyboard flexi and then convert from that to whatever, or just hook up the A500 controller to the A1200 motherboard. All the signals are available at the keyboard mcu's pins or if you have a 2B motherboard, there is a pin header where you can connect the signals to. Be aware; the 2B pin header has a different pinout to the A500 motherboard's keyboard connector.

[guybrush]

Thanks; so no direct conversion kit sadly. I was hoping for something I can plug the A1200 ribbon cable in and would make it a PS2 (I have an adapter for PS2 keyboards, which I got when I was planning for a tower conversion).

I have a 1D4 so no pin header; maybe I can find one of those inverted connectors that goes on top of the IC; the MCU is quite small as far as pins and my hand is not as steady

[Jope]

Well you could just go the A500 controller way and make your own cable + connections between the controller and a1200, then sell the ps2 adapter you have.

[guybrush]

Originally Posted by Jope

Well you could just go the A500 controller way and make your own cable + connections between the controller and a1200, then sell the ps2 adapter you have.

The problem is that I do not have an A500 keyboard; sourcing that would be quite a problem

[pandy71]

If this is so important then you can do this or by creating PCB and mimic/clone A1200 circuitry using uC populated on A1200 board or you can take generic uC and wrote own code to deal with A1200 keyboard and replace original A1200 circuitry or you can use 2 generic uC, one to serve A1200 keyboard and second mounted in A1200 at KB socket to reverse steps i.e. pretend to be just keyboard matrix. Third approach is least invasive and transparent so it could be nice as a market product (i could imagine A1200 and A600 versions).

[guybrush]

Originally Posted by pandy71

If this is so important then you can do this or by creating PCB and mimic/clone A1200 circuitry using uC populated on A1200 board or you can take generic uC and wrote own code to deal with A1200 keyboard and replace original A1200 circuitry or you can use 2 generic uC, one to serve A1200 keyboard and second mounted in A1200 at KB socket to reverse steps i.e. pretend to be just keyboard matrix. Third approach is least invasive and transparent so it could be nice as a market product (i could imagine A1200 and A600 versions).

That would be viable; I am pretty handy with micro and circuitry; although it is quite a lot of work If I would put this out as product, probably would be for free... There are already too many people selling all sort of stuff for Amiga, I don't need to make money; just enjoying being part of the community.



I will look into the matrix approach probably; I did something similar for a C64 keyboard using a teensy controller to convert the matrix to usb HID signals; but I have never done anything for PS2 protocol.


Another idea I have is just to make an extension that connect to the ribbon cable from the keyboard and to the ribbon connector of the amiga; which is probably the simplest way to go (if I can find the right ribbon cable of course)

[pandy71]

Originally Posted by guybrush

Another idea I have is just to make an extension that connect to the ribbon cable from the keyboard and to the ribbon connector of the amiga; which is probably the simplest way to go (if I can find the right ribbon cable of course)

In theory this may work unless I/O on KB uC aren't too weak to drive longer line - you can try to reduce number of wires by introducing fast analog multiplexing (like 74HC4051). Perhaps there is possibility to read firmware from KB uC on A1200 - not sure on 68HC05. If i recall correctly there is somewhere dump from original firmware on KB uC from A500.


---

Seem MAME has working A1200 MC68HC05 firmware dump: "dfa_rev_b_a1200_hc705.bin" so it should be possible to recreate original KB uC.

[Daedalus]

I ran an A1200 keyboard on a 2m length of ribbon cable for a few years and it worked just fine. It was not in the slightest bit elegant, but it was a temporary measure when I towered my A1200 that ended up lasting a few years until I got a NOS A2000 keyboard.

[guybrush]

Interesting, so a ribbon cable may work. I can just roll it probably to make it a bit nicer.

Do you remember how did you acquire the correct extension? Or did you make the ribbon yourself?

[AMike]

Not exactly what you are looking for - but maybe helpful.
https://www.ebay.de/itm/232254416783...cAAOSwOgdYs-CE

[Daedalus]

Originally Posted by guybrush

Interesting, so a ribbon cable may work. I can just roll it probably to make it a bit nicer.

Do you remember how did you acquire the correct extension? Or did you make the ribbon yourself?

Like I said, it was not an elegant solution I desoldered the ZIF socket from the motherboard, soldered that onto the end of the ribbon cable and secured that inside the empty A1200 shell (which I chopped the back off to make it smaller...), and at the motherboard end soldered a short ribbon to the motherboard pads and ran that to a 37-way D connector at the back of the tower case. A matching connector was fitted to the end of the ribbon from the keyboard and that was it.

A nicer solution if you were determined to go that way would be to have a small PCB made with a pin header so that you could easily crimp an IDC connector onto the ribbon, and make it thin enough to be inserted into the existing ZIF socket. Some existing keyboard adaptors follow this method, as do hard PCB replacement membranes. The ZIF connectors for the membrane are available, so a second small PCB at the other end would make for a much neater setup. Put them both on the one board in separate, snap-away sections and you can get them absurdly cheap.

[Jpor]

Originally Posted by guybrush

I know I can use PS2 and USB keyboards with the A1200, but I could not find much related to use a ribbon A1200 keyboard as external, instead of internal.


Basically something similar to a checkmate case, but just for the keyboard.


Did anyone ever made a kit for this purpose? Thanks

I run the PC-key 1200 on my A1200’s (1 in a Elbox Tower case and the other in a Checkmate 1500). This has a full AT Din connector which you can convert down to a PS/2 connector. Not tried this but you might be able to use a Ps/2 to USB converter as well.

Can be bought from Elbox here;

http://eu-shop.elbox.com/en_US/p/PC-Key-1200/634

If you want to use a ribbon A1200 keyboard then you will need something like a Keyrah;

http://amigakit.amiga.store/keyrah-white-p-1144.html

[OldAmigan]

I have a Keyrah, which lets me connect an A1200 (or A600) keyboard and turns it into a USB keyboard. My towered A1200 has a USB keyboard adaptor - so I'm hoping to use the now empty case, do what Rob did and chop the back off, to give me a proper Amiga keyboard.

I have no idea if it would be the type which would take a USB/PS2 adaptor, though

[rjd324]

Regarding the PC Key 1200, I still want someone to test the program in the zone: http://eab.abime.net/zone/test_w_a_s_d.lha because, for some reason, I am unable to get concurrent key presses for say A and D. I noticed this when I was playing Duke3D I could not move forward (W) and strafe (A/D) at the same time. Well, I noticed this on my PC Key 600 at first, then I tried it on the 1200 machine too.

This program shows concurrent presses with my A500 checkmate machine and on standard wedge cases without the PC-Key interface.

Would love it if someone could test and report back, because it might be a problem on my end!

[rjd324]

Can anyone with a PC-KEY of any type test out the program referenced in the previous post?

[Jope]

I'm not in a position to test the program for a week, but my experience with the PC-Key mirrors yours. It doesn't really seem to like NKRO or even quick typing.