Using an A500 keyboard with the Keyrah

[arnljot]

Which resources should I look into to give an A500 keyboard an A1200 connector (or A600 connector). I want to use an A500 keyboard on a Keyrah.

Sorry about the thread resurrection.

[Jope]

It already has an a1200 connector if it's a mitsumi keyboard. However it is quite a short one. Perhaps you can lengthen it.

[arnljot]

Originally Posted by Jope

It already has an a1200 connector if it's a mitsumi keyboard. However it is quite a short one. Perhaps you can lengthen it.

But is it signal compatible? My use case is the Keyrah. How can I tell apart the various a500 keyboard revisions?

[Jope]

Originally Posted by arnljot

But is it signal compatible?

Well the question you should ask: are the matrix and edge connector identical, and the answer is yes.

My use case is the Keyrah. How can I tell apart the various a500 keyboard revisions?

The mitsumi keyboard is the most common and has a single wide flat cable that connects the membrane to the controller board in the corner of the PCB.

It is possible to get an A1200 keyboard membrane, cut a hole for the flexi in the back of the keyboard backing plate and feed it out of there, then you can easily hook it up to the keyrah.

To make an A500 keyboard fit properly into an A1200 case needs a tiny bit of further trimming, but that was not the question here I guess.

[arnljot]

So, my options are:

1. Exchange the membrane for a 1200 one, cutting metal needed
2. Extend the membrane connector of the a 500 keyboard. Involves figuring out how to connect ffc end to end...

Either way there's still some metal cutting involved? Hmm, I think I'll exchange the membrane then. I guess it's in the upper left corner there's some dremel work needed due to the leds. All of this is in service to a mister fpga.

I wonder why the keyrah doesn't support the a 500 keyboard natively. A500 keyboards seems to be more available than 1200 keyboards.

[Jope]

Originally Posted by arnljot

So, my options are:

1. Exchange the membrane for a 1200 one, cutting metal needed
2. Extend the membrane connector of the a 500 keyboard. Involves figuring out how to connect ffc end to end...

Yes.

You can get the connector off the A500 keyboard controller and just solder a bunch of wires from it to the keyrah?

So you have an A1200 case and wish to install an A500 mitsumi keyboard?

Steps needed for A1200 membrane:
- buy the membrane
- remove the switch tray + controller PCB from the a500 keyboard (dozens of screws underneath)
- measure and cut a slot for the flexi at the back of the backing plate, the way I did it was to just hacksaw two slits into the metal around the edges of the flexi, then I hammered the metal in the middle straight so that the cable could come out

If you have an A500 case, you can stop here.

If you want to install it in the A1200 case too:
- trim rectangular hole the top right corner of the backing plate to be rather clean for the LED PCB to fit
- trim the top right corner of the switch tray to be straight so that the LED PCB will fit

Maybe I missed something, but once you have the parts in hand, you can apply your common sense to see what still needs doing.

Note the differences at the top right:
https://www.bigbookofamigahardware.c...dish_1_big.jpg
https://www.bigbookofamigahardware.c...dish_1_big.jpg

In the A1200 model, the screw hole for the controller is gone at the very top right, and the top of the switch tray is totally straight above the numpad. There is also another screw hole you need to cut out there above the numpad and there is also a sliver of metal at the very top right edge of the backing plate which you need to cut out. The metal work is a quick task with a steady hand + an angle grinder. The plastic is also quick to straighten with a handheld hacksaw.

[arnljot]

Wow, thanks for a thorough walk through.

My plans now are:
- Find my dremel, and look over my cutting and grinding discs
- Wait for Keyrah v2b to arrive from AmigaKit (I have no ideas if I can find a solder points at it which are relevant).
- Wait for new A1200 case from AmigaKit
- Wait for new A1200 keyboard membrane (NOS?) from german ebay seller

Then go to town and assemble it with my Mister FPGA in the case.

I'll update with pics when I have it all at hand.

[Photon]

I thought the KeyRah V2 solved the n-key rollover problem of the A1200 keyboard? I.e. if you want the same key mech they should be identical and you could plug in an A1200 keyboard instead of destructive deconstruction and hassle? I have this setup, I could test the rollover (if that's the hitch).

[arnljot]

I'd love to use an original a1200 keyboard Photon. But as it is, there are no repros for sale, and if there were they'd be at around $200 excl shipping. But I'd pay that, put that in my working A1200 and use the old keyboard with the Mister.

On Ebay it's completely dry, from the auctions and buy it nows is looks like all keyboards have been sold for parts keys goes for about £5, and then there's £20 shipping...

What I do have is access to a few a500 keyboards from broken a500s. Two of them have been parted out to restore other a500s, and one a500 wasn't mine but the owner gave me the partially cannibalized keyboard which I have restored by begging and buying the missing parts.

[Photon]

All right. I still think it sounds a bit desperate over say 30 EUR shipping. How about posting a buy ad here or on AmiBay? Here's a keyboard I found if UK layout is OK.

[arnljot]

I have an ad at Amibay.

Originally Posted by Photon

Here's a keyboard I found if UK layout is OK.

I'm keeping an eye on that auction, but I didn't want to draw attention to it as there are a few other unaswered a1200 kbd wanted ads at the amibay.

[Photon]

Ouch! Did I ruin it for you?

(And wow, I should sell all my keyboards and keep just the Amigas, I'd be rich and could afford the remake keyboards easy. )