Help needed for the SUM 1200 keyboard interface

[danbeaver]

I bought 2 of these (by https://retro.7-bit.pl/) to use external USB keyboards with case-based 1200s and none of the 6 keyboards I have tested work (4 are made by Rii, one is an unbranded from the CheckMate A1500 website, and one is an old Dell).

None work, even after flashing the only firmware update on the retro.7-bit.pl web site.

The company has no listed working keyboards, nor will provide me with any such list; they say the keyboards I am using draw too much power.

Does anyone have a working keyboard connected to a SUM 1200 device they can suggest?

[terriblefire]

I never had a SUM card. I had one from Electronica4u. That one worked very well until i broke the connector.

I would return it to the seller and ask for a refund.

[danbeaver]

Returning them leaves me fewer options than I already have.

[Ally]

Do you have access to PS2 ( IBM PS/2 ) keyboards?

Someone I know made me a couple of A1200 PS2 keyboard adapters (I have yet to test)
I'd prefer not to part with them but if I test it and it works I could spare one and ask him if he'd consider making a couple more?

If memory serves they were in the ballpark of £20 each, tho that was some time ago and with price fluctuations who knows.