[johnwalkr]

I work in this space and z80, kermit and xmodem are not part of the solution. Just because this stuff is simple to the user doesn't mean it's the best suited, and there's a whole industry working on this since the Z80 days. You can buy space-qualified microcontroller boards/components with anything from a simple 8 bit microcontroller to a 64-bit, multicore, 1Ghz+ ARM cpu depending on the use case. I'm sure Z80 has been used in space, but in my time in the industry I've never heard of it.

Kermit and xmodem probably aren't what you want to use, they are actually a higher level than what is normally used and would require a big overhead, if they even worked at all with latencies that can reach 5-10s. Search for the keyword "CCSDS" to get hints about data protocols used in space.

[kristopolous]

I worked in it 20 years ago building diagnostic and networking tools ... arm was certainly around but there was also what I talked about. Things probably changed since then.

Here's kermit in space ... coincidentally in a 20 year old article. Software I wrote supported diagnosing kermit errors.

https://www.spacedaily.com/news/iss-03zq.html

I guess now I'm old.

[johnwalkr]

Thanks for the reference! Kermit could be used locally on ISS or in a lunar mission now that I think about it, but so is/could SSH, web browsers or any modern technology. But most space exploration is robotic and depends on communication to ground stations on Earth, and that is fairly standardized. Perhaps kermit will be used on the lunar surface, and that will be a simplification compared to a web browser interface. But for communication to/from Earth and Moon, there are standards in place and it would be a complication, not simplification to add such a protocol.

[kristopolous]

oh who knows ... I stopped working on that stuff in I think 2006. The big push then was over to CAN and something called AFDX which worked over ethernet. I was dealing with octal and bcd daily, mid 2000s.

I have no idea if people still use ARINC-429 or IRIG-B. Embedded RTOS was all proprietary back then for instance, like with VXWORKS. I'm sure it's not any more. I hated vxworks.

[lambda]

Yeah, I'm working on a fly by wire eVTOL project, we are using the CAN bus as our primary bus, but there are a number of off the shelf components like ADAHRS that we use that talk ARINC-429 so our FCCs will have a number of ARINC-429 interfaces.

But at least for the components we're developing, we have basically standardized on ARM, the TMS570 specifically since it offers a number of features for safety critical systems, and simplifies our tooling and safety analysis to use the same processor everywhere.

Z80 is pretty retro, and while I'm sure there may be some vendors who still use it, it's got to be getting pretty rare for new designs, between all the PowerPC, Arm, and now RISC-V processors available that allow you to use modern toolchains and so on, I'd be surprised if many people were doing new designs with the Z80