CIDCO Phone keyboard convert help

[Serbaside]

I picked up a 'CIDCO' CST2100 phone 60% keyboard at a thrift store that I would like to use with a computer but it isn't PS/2 protocol (it does have the same 6 pin connector, but only 5 pins are used).

Does anyone have any resources on how to convert the connection? Maybe using an Arduino? When I plug it into a standard PS/2 port the lights flash so it has power but it doesn't actually connect.

The chip on the inisde is a P87C51.

[EkriirkE]

Do you still have this keyboard intact?  If you don't want it any longer I have a Cidco device that could use it...