My first “rack” was made of wood. It monitored, meaning displayed and alerted, on some metrics on my Linux server. And controlled a few lights and the alarm system in my room.

I really enjoyed making the computer control the lights.

It contained:

  • A ISA I/O card
  • 15" CRT monitor, keyboard and mouse
  • Parallel port IO module
  • Red and green maritime lanterns
  • Yellow strobe
  • Stack lights (green and yellow)
  • Switch and key switch
  • Computer power supply
  • Terminal block
The rack
Backside of rack, with terminal connectors, power supply and I/O modules


The controlling software was written in Visual Basic. It allowed socket connections, making it possible to push commands from the Linux terminal and a “web-UI”.

Rack Supervision, written in Visual Basic
Web front-end

Last commit 2021-08-06, with message: replace some youtube videos