Let’s take a moment to marvel at the design of the Voyager spacecraft software - written in assembly language for a custom 1970s CPU, in less than 70 KB of RAM, able to react to failures and keep comms. up.
Possibly, NASA may have to turn off one more instrument on Voyager 1. Over the 47 years since launch, Voyager instruments have gradually been shut off as power levels have declined by over 50%.
But the Voyagers continue to boldly go where no spacecraft has gone before.
4/n
@elaterite @simonbp
Looks like the Voyager CCS computer had just 4k 18-bit words of plated-wire memory.
Instructions consisted of a 6 bit op code and 12 bit address. This permitted 64 instructions and 4K of direct addressing.
Average instruction cycle time was 88 us (11.4 KIPS).
13 registers incl an 18-bit accumulator, 12-bit program counter, 12-bit link register that pointed to the next address to be read, and a 4-bit condition code register.
https://ntrs.nasa.gov/api/citations/19880069935/downloads/19880069935_Optimized.pdf