Using a Raspberry Pi as a Gateway

Why do I need a Gateway?

The current situation of my MV/2500DC is that I have AOS/VS (Classic) running with little but the base software. In particular I do not have the TCP/IP bundle, so I cannot access the machine via the LAN. What I do have working are 32 (!) serial ports which were originally intended to be directly connected to serial DASHER terminals.

Although I do have a number of physical DASHER terminals I am reluctant to run them too frequently and risk screen burn-outs and other component failures; I would rather use my DasherQ terminal emulator.

In addition to wanting local access to the machine I like to provide remote access over the internet so that interested parties can use my MV at agreed times.

Hardware

DG-Side

On the DG side of things I have hooked up a 32-way serial distribution board to the MV via the chunky cables that came with it. I am one cable short, so the maximum number of serial ports I can access is 24.

Pi-Side

USB-Serial Adaptors

Software

No special software is running on the MV. It is just configured in the standard 80’s way for serial terminal access.

Ser2Net

The pertinent part of /etc/ser2net.conf is this…

BANNER:banner:\r\nser2net port \p device \d [\s] (Raspberry Pi Debian GNU/Linux Gateway to MV/2500 DC)\r\n\r\n

2000:telnet:3600:/dev/tty1:9600 8DATABITS NONE 1STOPBIT banner
# 2001:telnet:600:/dev/ttyS1:9600 8DATABITS NONE 1STOPBIT banner
3000:telnet:3600:/dev/ttyUSB0:9600 8DATABITS NONE 1STOPBIT banner
3001:telnet:3600:/dev/ttyUSB1:9600 8DATABITS NONE 1STOPBIT banner
3002:telnet:3600:/dev/ttyUSB2:9600 8DATABITS NONE 1STOPBIT banner
3003:telnet:3600:/dev/ttyUSB3:9600 8DATABITS NONE 1STOPBIT banner
3004:telnet:3600:/dev/ttyUSB4:9600 8DATABITS NONE 1STOPBIT banner
3005:telnet:3600:/dev/ttyUSB5:9600 8DATABITS NONE 1STOPBIT banner
3006:telnet:3600:/dev/ttyUSB6:9600 8DATABITS NONE 1STOPBIT banner
3007:telnet:3600:/dev/ttyUSB7:9600 8DATABITS NONE 1STOPBIT banner