Aircraft avionics teardown – Honeywell symbol generator

I obtained another interesting piece of aircraft avionics – this time a symbol generator computer that is used for generating the graphics and video signals for the CRT displays in the cockpit. From what I can gather there is typically 2-3 of these units in the aircraft with each symbol generator driving two displays so there would be one for each side of the cockpit + one backup.

It dates from around 1990 so it’s approximately 30 years old at the time of this article. The electronics inside are very space age with radiation hardened gold topped IC’s.

Video card (rear PCB)

It consists of various cards which are 2 x video driver boards, the CPU board, WXR scan converter board and several I/O boards. The computing technology isn’t anything to write home about but it would have been state of the art at the time. There is an Intel 80c86 used as the main CPU with some Zilog Z180 compatibles on the video cards.

Here’s a photo gallery with descriptions of the boards and a YouTube video

YouTube video