I’d take issue with your statement that the Kermit protocol isn’t complicated. The base protocol isn’t, but when you throw in all of the extras, it becomes extremely complicated.
Can you write a Kermit with only the simple stuff? In theory, yes. In practice, not so much. Many Kermit implementations make bad assumptions about what’s available on the other end. Now add to that the complexity of serial IO programming. I’ve heard a lot of people piss and moan about how bad serial port programming is under unix, but under RTE it was a nightmare. I suspect other minicomputer OSes were the same way. Trust me, I’ve been there. I tried writing a Kermit implementation on RTE 30 years ago. I eventually gave up because of the complexity and the mind-numbingly difficult task of getting RTE to do what you want with a serial port. Someone did eventually get one written, and I used it extensively, but I guarantee you he put a *lot* of time into it. From: Simh [mailto:[email protected]] On Behalf Of khandy21yo Sent: Wednesday, April 20, 2016 4:51 PM To: Sampsa Laine <[email protected]>; Phil Budne <[email protected]>; [email protected] Subject: Re: [Simh] Way out idea for simh The Kermit protocol isn't very comp,icated, is well documented, and has a lot of testing behind it. What happens in your protocol with characters that devices between you and the simulator mangle. Modems were a major frustration, now you have all sorts of effort devices may do funny things with certain haracters. Send the wrong characters and it could disconnect. We've been through this before, why not make use of that experience. Sent from my Galaxy Tab® A -------- Original message -------- From: Sampsa Laine <[email protected]<mailto:[email protected]>> Date: 04/20/2016 2:35 PM (GMT-07:00) To: Phil Budne <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [Simh] Way out idea for simh > On 20 Apr 2016, at 23:25, Phil Budne > <[email protected]<mailto:[email protected]>> wrote: > > Ken.Cornetet wrote: >> I guess I need to shout this: >> ******* KERMIT DOES NOT WORK ON SIMH EMULATED RTE-6/VM ******** > > Why not? > >> Kermit does not exist (and probably couldn't feasibly exist) on any earlier >> versions of RTE. > > Again, why not? > > Having just written a new shell for PDP-7 UNIX (because the original > could not be found), I can't imagine much other than a lack of > something resembling a serial console that would prevent _some_ > version/subset of KERMIT (or something similar like X or ZMODEM) from > being cobbled together. > And since the connection can be assumed to be lossless, the protocol could be really simple, e.g. something like this: G=Guest, H=Host Example of a write operation.. G: WRITE-FILE H: ACK // Now we send the file structure / word size etc G: FILE-META-DATA G: <file size and a bunch of OS specific stuff that is written to a second file> H: ACK G: FILE-DATA G: <the actual data> G: ACK Done. _______________________________________________ Simh mailing list [email protected]<mailto:[email protected]> http://mailman.trailing-edge.com/mailman/listinfo/simh
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