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jack will miss this server

@kenshirriff it's astonishing what engineers had to come up with before reliable electronic displays

this is an RAF Ground Position Indicator Mk4A, a navigation computer from the 50s/60s, used in transport aircraft and some of the early jet bombers. it takes true heading, groundspeed, and drift angle inputs (the last two from a Doppler radar) and integrates to track the aircraft's movement from a known starting point

an RAF Ground Position Indicator Mk4A from the 1950s/1960s, along with a large aircraft navigator's compass and a Doppler groundspeed/drift angle indicator. the GPI Mk4A displays north/south and east/west position on two roller-counter displays. a circular gauge shows aircraft heading and drift angle. the front panel is about 20cm square with half a dozen knobs and switches
the GPI Mk4A with its cover removed. it is ~50cm deep and packed full of shafts, gears, motors, mechanisms, and intricately routed wiring
28 September at 15:46 | Wall-to-wall | Open on strangeobject.space
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Ken Shirriff

@JackEric That's a nice navigation computer!

28 September at 15:56 | Open on oldbytes.space
jack will miss this server

@kenshirriff I made a simulation of this in X-Plane and the code for the core behaviour of the computer is a few lines of code - and most of that is for the "fix" function, where the inputs update the memory drums instead of the display rollercounters so you can make a correction. when you move the switch back to "normal" the memory drums are driven back to the zero position and they update the display drums as they do so
28 September at 16:08 | Open on strangeobject.space
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