Keyboard Converter: Consul 262.5 & VDX 52600

Arduino project for a keyboard converter between a Zbrojovka Consul 262.5 terminal keyboard and a Videoton VDX 52600 terminal.

Keyboard: Consul 262.5

Terminal keyboard from 1980s. It uses a DB25 connector with UART TTL data lines, clock line, +5V primary power and -12V auxiliary power.

Terminal: VDX 52600

VT52 termnial with a DIN5 keyboard connector that dones not use the standard AT keyboard protocol.

Converter

Interfaces the keyboard and the terminal, optionally a USB. These modes of operation are supported:

1. Keyboard and terminal connected: primary standalone mode. Everything is powered from the terminal.
2. Keyboard and USB connected: USB keyboard mode. Powered from the USB which acts as a HID keyboard.
3. Terminal and USB connected: Serial keyboard over USB mode. Powered independently. Allows sending keystrokes to the terminal over USB serial.

Parts needed

• Arduino Leonardo
• Symmetrical boost converter, 5V to +/- 12V
• Piezo speaker
• red and green LED + 470 ohm resistors
• connectors
• project box
• (among others)

Connections

TODO

Terminal DIN5

Device	Controller	Description
GND	GND	Ground
+5V	+5V	Power
Data	6	Keyboard data to terminal
Status	7	Status (LEDs) from terminal

Keyboard DB25

Device	Controller	Description
GND	GND	Ground
+5V	+5V	Power
-12V	-12V	via a symmetrical boost converter
Serial out	3	UART out from keyboard
Serial in	4	UART in to keyboard

Box Interface

Controller	Description
10	Offline LED
9	Online LED
8	Speaker