I found a Focus FK-2001 terminal keyboard in the garage. My dad first used it in the 90’s when he started programming. It’s honestly still pretty nice for being in storage for 10+ years.
Initially, to connect the 5 pin DIN cable to my modern computer, I used a 5 pin DIN to PS/2 adapter and a PS/2 to USB adapter.
the chain of adapters
First things first, I took it apart and cleaned it throughly. I dusted out the innards with an air duster and wiped down all the keycaps.
out of the case
I found that some of the keys (space and left ctrl) seemed to be double pressing. I desoldered and swapped the troublesome switches with working switches.
I really like the beige retro color of tech from this time period. The switches are Alps SKCM whites or a clone, I’m not entirely sure.
Since the adapter chain is bit unsightly, I decided to use a Pro-Micro to adapt the keyboard to use USB.
The pins of the original cable connector are labelled C, D, G, and V for clock, data, ground, and voltage respectivley.
C, D, G, V labels on the pcb
I connected these pins to the Pro-Micro’s PD0, PD1, RAW, and GND, then I flashed the Pro-Micro with Hasu’s terminal keyboard converter.
Luckily, there was a hole in the back of the case that was just big enough for a USB mini port so I didn’t have to do any drilling.
pro-micro in place
usb mini-b port
I didn’t have heat shrink at the time so I hotglued the wires for insulation and stability (don’t worry, I soldered them first).
I also used a stack of cardboard and electrical tape to support the Pro-Micro in the case. Not the prettiest solution, but no one’s going to see it inside the case.