[Simh] Way out idea for simh

[Ken Cornetet]

Because in operating systems earlier than RTE-6/VM, code had to fit in a couple dozen kbytes of address space.

You could create what are called "segments" which were kind of like dynamically loaded subroutines, but there were many coding issues using those.

Even in RTE-6/VM where you had a whopping 62k bytes of address space, the auther of RTE Kermit had to resort to segments, and some ugly hacks to get it shoehorned in.

Yes, in theory, a very simple Kermit might be able to be written, but it would probably have to be written in assembly, and it would have to be limited to ONE version of serial IO hardware, and ONE version of the firmware on that serial IO mux, and ONE version of the RTE driver (serial IO was an absolute nightmare in RTE).

HP intended serial IO for one purpose and one purpose only - to talk to an HP terminal. I think they intentionally made it byzantine to dissuade users from connecting non-HP devices to RTE systems.

Even if you got it to work, there is only one usable terminal emulator that I know of for RTE that I know of (QCTerm) and it does not support Kermit. RTE *really* wants you using an HP terminal. Trying to use any other terminal type is an exercise in frustration.

And on top of that, you'd have to hope that all of the possible combinations of serial IO settings on the RTE side are mapped to the right telnet options, and that there aren't any bugs or limitations in said implementation.

Just because Kermit works on one or two simh guest OSes, I wouldn't extend that as proof that the serial-to-telnet mapping is robust enough to handle all guest OSes.

-----Original Message-----
From: Simh [mailto:simh-bounces at trailing-edge.com] On Behalf Of Phil Budne
Sent: Wednesday, April 20, 2016 4:25 PM
To: simh at trailing-edge.com
Subject: Re: [Simh] Way out idea for simh

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.

Phil
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