81 lines
2.2 KiB
Markdown
81 lines
2.2 KiB
Markdown
# Keyboard Converter: Consul 262.5 & VDX 52600
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![Terminal with keyboard and the converter](overview.jpg)
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Arduino project for a keyboard converter between a Zbrojovka Consul 262.5 terminal keyboard and a Videoton VDX 52600 terminal.
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## Keyboard: Consul 262.5
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Terminal keyboard from 1980s.
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It uses a DB25 connector with UART TTL data lines, clock line, +5V primary power and -12V auxiliary power.
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## Terminal: VDX 52600
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VT52 termnial with a DIN5 keyboard connector that dones not use the standard AT keyboard protocol.
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## Converter
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Interfaces the keyboard and the terminal, optionally a USB. These modes of operation are supported:
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1. Keyboard and terminal connected: primary standalone mode. Everything is powered from the terminal.
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2. Keyboard and USB connected: USB keyboard mode. Powered from the USB which acts as a HID keyboard.
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3. Terminal and USB connected: Serial keyboard over USB mode. Powered independently. Allows sending keystrokes to the terminal over USB serial.
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![Converter box](box.jpg)
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## Parts needed
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- Arduino Leonardo
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- Symmetrical boost converter, 5V to +/- 12V
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- Piezo speaker
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- red and green LED + 470 ohm resistors
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- connectors
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- project box
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- (among others)
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## Connections
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### Terminal DIN5
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Device | Controller | Description
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---|---|---
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GND | GND | Ground
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+5V | +5V | Power
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Data | 6 | Keyboard data to terminal
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Status | 7 | Status (LEDs) and Clock from terminal
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![DIN5 connector pinout](DIN5_pinout.jpg)
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### Keyboard DB25
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Device | Controller | Description
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---|---|---
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GND | GND | Ground
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+5V | +5V | Power
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-12V | -12V | via a symmetrical boost converter
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Serial out | 3 | UART out from keyboard
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Serial in | 4 | UART in to keyboard
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### Box Interface
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| Controller | Description |
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| ---|--- |
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| 10 | Offline LED |
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| 9 | Online LED |
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| 8 | Speaker |
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### Terminal DB25
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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.
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See [RS-232 over DB25 connector](http://www.nullmodem.com/DB-25.htm) for more.
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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.
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