[Simh] A simulated modem for SimH + details of -a and -m?
Hi all, I've written the beginnings of a simulated modem so that one SimH
instance can "dial"out to one of many remote SimH instances, rather than
dedicating a serial line for each one. See
https://github.com/DoctorWkt/4bsd-uucp/blob/4.3BSD/tcpdial.md
I'm trying to work out what is the best combination of -a and -m flags
to set on the "Connect" serial line and on the listening serial line to
make this work. I've read through sim_tmxr.c and PDP11/pdp11_dz.c but
I need someone to hit me with a clue bat. Could someone help me off-list?
I'm happy to extend this to have a few more Hayes modem commands, if
if would be of use for other simulated systems.
Cheers, Warren
P.S. I did look at tcpser, it requires one end to be a real serial port
P.P.S Algorithm:
bind and listen to local port
forever {
accept connection on local port
receive data until a dial command
look up dialed number to get associated remote server:port
if (no such number) close connection, loop back
make TCP connection to matching remote server:port
if (not able to make connection) close local connection, loop back
while (both connections are open) {
pass on data in both directions
}
close both connections
}
signature.asc
Description: PGP signature
___
Simh mailing list
Simh@trailing-edge.com
http://mailman.trailing-edge.com/mailman/listinfo/simh
[Simh] A couple of newbie SimH questions
Hi all, as part of the preparation for the Unix 50th anniversary in 2019, I'm starting to get some Unix images up and running on SimH. What I want to get done is to recreate some of the early networking, in particular uucp and Usenet on top of it (with C-News). I've built 4.2BSD and 4.3BSD images as per the instructions here: http://gunkies.org/wiki/Installing_4.2_BSD_on_SIMH http://gunkies.org/wiki/Installing_4.3_BSD_on_SIMH and these run fine on SimH VAX 11/780 simulator V4.0-0 Beta git commit id: 7c5792e9 I've tried all of the SET CPU IDLE values and I can't find a value that lowers the CPU usage below 100%. Is there a compile flag that I need to set? The host system is Ubuntu 15.10 and Linux 4.2.0-42-generic. I've set up a DZ device with: set dz lines=8 att dz set dz 7b and I can happily telnet in. Now I want to set up two SimH instances so that one DZ line connects the two together. I've read the vax780_doc.doc but I can't see how to configure an outbound connection. Many thanks for any tips and suggestions, Warren signature.asc Description: PGP signature ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
[Simh] Questions about PDP-7
Hi all, recently we unearthed a set of pages that contain assembly listings of the PDP-7 Unix kernel and some associated user-mode programs. See the files 0*.pdf at http://www.tuhs.org/Archive/PDP-11/Distributions/research/McIlroy_v0/ There's a move afoot to see if we can bring this up on a real PDP-7 and also on SimH. I've set up a mailing list if anybody wants to help out, and my initial Github repository is at https://github.com/DoctorWkt/pdp7-unix I've got some PDP-7 questions and also some SimH PDP-7 questions. What is the format of disk blocks that SimH stores for the 18-bit systems? In other words, how are the 18-bit words in each block stored in the bytes of the host systems? At some point we will need to write a tool to generate a filesystem, so this information will be crucial. A general PDP-7 question: how are ASCII strings stored in memory? Are they 7-bit or 8-bit? I'm assuming that two ASCII characters are stored in one 18-bit word, but which bits go where? If I had the string "abcd", which bits go where in the two 18-bit words? Thanks in advance for all your help, and also thanks to RMS and others who wrote Simh as it's been an invaluable tool to keep the PDP-11 and Vax Unix systems going. Cheers, Warren ___ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh
