What the team is doing during lockdown: Mike Stewart reverse engineers an Apollo Computer Buffer Unit (Patreon)

Mike got an Apollo Computer Buffer unit from one of the last RRauction. This box was part of the ground support equipment, and allowed launch control to upload launch related parameters that could not be woven in the Core Rope into the AGC. This box is a serializer that takes a 16 bit input and transforms it into a transformer coupled serial bitstream that is fed to the AGC. 

From Mike's explanation:

The Computer Buffer Unit was part of the DTCS (Digital Test Command System), which itself was part of the ACE (Automatic Checkout Equipment). I think there were installations of this at the various Apollo field centers, but the primary use was at the Saturn launch pad. The Computer Buffer Unit sat at the top of the mobile launch tower and sent prelaunch configuration commands (pad loads, etc.) into the AGC. It took in a 16-bit parallel word from the DTCS and turned it into the transformer-coupled serial pulse stream as required by the AGC. Here's a picture of it from Motorola, the buffer unit is the small box on the far right (see blue picture attached).