Pic of the Flight Data Subsystem (FDS) computer board KIPS = Kilo instructions per second DMA = Direct memory Access RTG = Radioisotope Thermoelectric generator Image source: https://www.allaboutcircuits.com/news/voyager-mission-anniversary-computers-command-data-attitude-control/

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1. AkaSci 🛰️ (akasci@fosstodon.org)'s status on Wednesday, 22-May-2024 21:20:15 UTC AkaSci 🛰️

   in reply to

   Some tech. info on the Voyager FDS computer –
   - There was a backup FDS unit but it failed in 1981.
   - Custom CMOS CPU - 36 instructions. 80 KIPS, 115 kbps data rate.
   - 128 registers, kept in memory.
   - CMOS memory, a first in space, 8KB.
   - No separate memory for program storage vs execution. The CMOS memory is non-volatile kept powered on by the RTG.
   - DMA access to memory by hardware. Instead of “cycle-stealing”, the instructions indicated cycles where DMA can occur.

   https://ntrs.nasa.gov/api/citations/19880069935/downloads/19880069935_Optimized.pdf
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