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Here I managed to obtain another piece of aircraft avionics from the airplane graveyard, this time a Honeywell Symbol Generator. This is basically the device that takes all the information from the various aircraft systems and sensors and generates the graphics and video signals to drive the cockpit CRT displays. There are typically two or more of these symbol generators; one for each side of the cockpit. Inside there are various boards containing gold topped radiation hardened IC's - the sort of thing that would not look out of place on a spacecraft. This thing dates from around 1991 so the computing technology used isn't much to write home about. There's an Intel 8086 used as a main CPU and a Zilog Z180 compatible used on each of the video generator boards. RAM size on the boards is 16kb - 128kb of SRAM which uses parity / error checking on some PCB's. This must have been very expensive when new but unfortunately it's just scrap value now as I believe this model was only ever used on the BAE146 and it's variants. The boards inside depend on the aircraft configuration as there are a couple of option slots with one populated. A chance to see what the sort of technology you see in your average airliner except for the newer models such as the A330-NEO, A350, A380, 737MAX etc. They obviously use much newer technology not that different from a computer datacenter where many of the functions previously done by individual boxes in the avionics bay are virtualized on servers running an RTOS. Typical processors used are several Intel Xeons; well in the case of the A380 anyway. It didn't cost much but it is certainly an interesting teardown. Virtually no salvageable parts from this one but was nice to take a look at it in detail. Photos of the PCB's with descriptions of chips I could identify can be found on my blog #avionics #BAE146 #teardowns
