On Fri, Jul 5, 2024 at 8:31 PM John R. Hogerhuis <[email protected]> wrote:
> Mars Pathfinder Sojourner rover onboard processor used a flight-qualified > Intel 8085 running at 100 KIPS > Oh, cool. I didn't know any 8085s had made it to outer space! While I was looking up the bar code program listings, I just noticed that one of the articles in the March 1985 issue of Portable Computing Magazine is entitled "A Po[rtable] Co[mputer] performance that is out of this world — *Model 100 on the space shuttle*" by Jim Hawk. Sadly, that issue is one of the ones that is missing from Internet Archive's PCM collection, so I have no idea if this is something that actually happened. In attempting to verify it, I did find NASA's source code for the Apollo 11 guidance computer and it is surprisingly well-commented and uncomplicated. For example, here is the famous P51 program <https://github.com/chrislgarry/Apollo-11/blob/9c5454cd2751eb778541e68efcd4887ac6d7d1a4/Comanche055/P51-P53.agc#L1308> which Apollo 12 used to reset their ship's IMU (inertial orientation) by sighting stars with a sextant. (That wasn't in the mission plan, but everything went haywire when they got hit by lightning. Twice.) It looks like the code is essentially 3x3 matrix multiplications plus a table of stars <https://github.com/chrislgarry/Apollo-11/blob/master/Comanche055/STAR_TABLES.agc> . Everything I've seen is clearly within the realm of a Model T except possibly the hardware interrupts, and I could be wrong about that. It seems like even from BASIC one can do some powerful things, like ON COM GOTO to set an interrupt whenever data comes in on the serial port. I like the idea of distributing a mini phonograph with a cassette program. > That was done at least once. But I guess you'd have to figure out how to do > it in space since most players rely on gravity to hold down the needle arm. > Now, this I love very much. A teeny-tiny gramophone playing miniature versions of the golden record, like we sent out on V'ger <https://www.youtube.com/watch?v=fKX21xp6hhA>. It wouldn't even require air to work, just electricity to amplify the signal for the Model T. Of course, records and needles wear out, so it might not be the most practical solution. Definitely the coolest, though. As for gravity, I used to have a portable phonograph that was designed to play sideways— it came with a strap so you could wear it like a walkman — so it is doable. Or, if you have electricity, you could bounce light off the disk which not only doesn't need gravity but saves on wear and tear. Though a space-faring race might take a longer view and be concerned that they won't have manufacturing capabilities to replace an LED laser since even those burn out. On Sun, Jul 7, 2024 at 7:18 PM Walt Perko <[email protected]> wrote: > Interface Age Magazine published a bunch of “Floppy ROMs” … I have a few > of them. I think they’re for the Altair 8800 … > Okay, now we're talking durability — I know EEPROMs are fickle, but don't ROMs last essentially forever when treated right? And the Model T computers have an open socket for just such a thing! Though of course that raises the question of how folks on a spaceship would make custom ROMs. I am imagining space mariners hand-weaving their own rope memory <https://en.wikipedia.org/wiki/Core_rope_memory> (read only core memory) on long journeys in empty space, similar to how whalers used to carve intricate scrimshaw designs while in the doldrums. —b9
