Save-a-Term is a reverse keyboard adapter to use a regular PS/2 keyboard on the original IBM 5251 and 3278 terminals.

You got a pretty vintage 5251 or 3278 terminal but it lacks the original keyboard. The original keyboards are very expensive and sought-after items that can easily go for thousands of dollars. This adapter tries to solve that problem giving a way to use a cheap standard PS/2-like keyboard with the original terminals.

The adapter will auto-detect the terminal type (5251 or 3278) and use the correct scancode set and signal polarities for the connected terminal.

The adapter emulates the clicker functionality of the original keyboards using a buzzer to give audible feedback while typing. The buzzer volume can be adjusted using the on-board potentiometer.

The included DIP switches allow to configure a 4-bit keyboard-id for the terminal.

The adapter is housed in a sturdy 3D-printed case.

To use the adapter you simply have to plug your keyboard to one of the 4 available ports (RJ45, DIN5-240º, DIN5-180º, PS/2). It will work with any IBM XT/AT/PS2 or compatible keyboards on any scancode set (1,2 or 3). The recommended keyboard is an XT layout for the 5251 terminal (like on the original IBM PC keyboard) and a M122/F122 terminal layout for the 3278 terminal. The adapter is not compatible with USB keyboards.

For the connection from the adapter to the terminal you have to use a male-to-female straight DB-25 cable (not included). The adapter will get power from the terminal connector, so no external power is needed.

This adapter is not compatible with other similar IBM terminal connectors like 3277, 5291 or Displaywriter, so do not use it with those.

All the information about the converter is available on my Github: https://github.com/inmbolmie/Save-a-Term