[Simh] Way out idea for simh

[Paul Koning]

> On Apr 20, 2016, at 3:58 PM, Kevin Handy <khandy21yo at gmail.com> wrote:
> 
> I think you are trying to over-engineer this file transfer stuff.
> 
> Instead of creating new devices for the transfer to operate over, why not use something that already exists on most of the simulators, like a serial port. 
>  Instead of building all this code into simh to convert from one disk file
>  format to another. inside the simulator, use a progrm attached to the serial port which handles the hosts file access. You will still need a program on the simulated system to handle it's side of the transfers. W can give the whole setup a common name, like "kermit".
> 
> Most of this stream just seems to me to re-inenting Kermit in one way or another. It might be fun/interesting but doesn't seem to gain anything beyond what Kermit already does.

Sort of.  But Kermit does a whole lot more, things that are not needed here.  Kermit assumes a lossy interconnect with errors, while here that assumption is not needed.  And even E-kermit is fairly large -- 1600 lines of C code.  Simply to say "send me file "foo" now, with the reply being simply a stream of bytes would be at least an order of magnitude simpler.  The obvious data format would be the SimH tape record format -- a block of bytes preceded by a byte count.

Attaching all this machinery to serial ports makes a lot of sense, assuming you have them.  Most machines do, though some (again, the IBM 1620 is a good example) all you have is a console, and paper tapes).  Some (like the EL-X1) don't even have a bidirectional console port.

	paul