I used to have it in my head that the Voyager probes were about as powerful as an Apple II computer. But it's hard to make a direct comparison as the probes have three computers made of two processors each, running at 1/20th or 1/6th the speed of an Apple. So it's not a one-on-one comparison in any way, but for discussion purposes:
An original Apple II used a MOS 6502 8-bit word CPU clocked at 1.023 MHz and typically had 4Kb to 48Kb of RAM. It ran about 500,000 instructions per second [1].
Computer Command System (CCS) - two 18-bit word interrupt-type processors with 4096 words each of plated wire memory. It ran about 25,000 instructions per second. [2]
Flight Data System (FDS) - two 16-bit word machine with modular memories and 8198 words each of memory. It ran about 25,000 instructions per second. [2]
Attitude and Articulation Control System (AACS) - two 18-bit word machines with 4096 words each of memory. The AACS ran about 80,000 instructions per second. [2]
So maybe the total amount of computing power is equal? The total memory on a Voyager was about 32K [3], and since the word sizes were bigger, theoretically they could access larger chunks of memory in a single instruction? What's for sure is that a single CCS is at least an of magnitude less powerful than an Apple II.
>So maybe the total amount of computing power is equal?
Probably not. Those 18bit words likely contain 2 bit parity to prevent space radiation from making this go bad. Plus, it's only one machine, not two, the two always run in parallel (for the CSS, the FDS only has one running at a time and AACS is turned off if not needed) and redundantly in case on fails, so in total you're running about 180'000 instructions per second, not 360'000. The memory totals 34 kilobytes (18bit words in two of the memories, 16 in the third), with a simple redundancy like the computer itself (ie, each computer has it's own memory).
The CCS is also responsible for managing the memory of the other two systems (MEMLOAD), so their realistic instruction speed may be limited by slower memory access in memory heavy applications.
Even all systems combined, I don't think the voyager is faster than an Apple II within an order of magnitude.
An original Apple II used a MOS 6502 8-bit word CPU clocked at 1.023 MHz and typically had 4Kb to 48Kb of RAM. It ran about 500,000 instructions per second [1].
Computer Command System (CCS) - two 18-bit word interrupt-type processors with 4096 words each of plated wire memory. It ran about 25,000 instructions per second. [2]
Flight Data System (FDS) - two 16-bit word machine with modular memories and 8198 words each of memory. It ran about 25,000 instructions per second. [2]
Attitude and Articulation Control System (AACS) - two 18-bit word machines with 4096 words each of memory. The AACS ran about 80,000 instructions per second. [2]
So maybe the total amount of computing power is equal? The total memory on a Voyager was about 32K [3], and since the word sizes were bigger, theoretically they could access larger chunks of memory in a single instruction? What's for sure is that a single CCS is at least an of magnitude less powerful than an Apple II.
More info:
1) http://www.classiccmp.org/cini/pdf/Apple/Apple%20II%20Refere...
2) http://www.cpushack.com/space-craft-cpu.html
3) https://web.archive.org/web/20110721050617/http://voyager.jp...