2.2 KiB
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:
- Keyboard and terminal connected: primary standalone mode. Everything is powered from the terminal.
- Keyboard and USB connected: USB keyboard mode. Powered from the USB which acts as a HID keyboard.
- 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
Terminal DIN5
| Device | Controller | Description |
|---|---|---|
| GND | GND | Ground |
| +5V | +5V | Power |
| Data | 6 | Keyboard data to terminal |
| Status | 7 | Status (LEDs) and Clock 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 |
Terminal DB25
The VDX 52600 terminal uses the standard DB25 serial connector to connect to an RS-232 serial link. It is enough to connect pins (2) TX, (3) RX and (7) GND. See RS-232 over DB25 connector for more.
By default the serial port configuration is 9600–8-N-1 (i.e. the standard baud rate of 9600). Connecting it to a serial port of a Linux machine works nicely.