[Simh] Unix V7 for PDP11

[Tim Newsham]

> Hello averybody. I'm spending some time in my vacations period with Unix
> V7 under the PDP11 simulator of SIMH. In appeareance there aren't SYS
> sources in the RL02 image disk, and I should need them to change some
> parameters of the system and compile the kernel. I could locate one
> Japanese place where the guy explains how to load the source code in the
> RL02 image using wget to catch the source code, tar to pack it, one perl
> script for the blocksize and then load inside SIMH over the RL02.
> Interesting at least (I must check it).

You can easily put them onto a "tape" and extract them from
inside the pdp.  I wrote a utility for reading and writing
tape format files:

   http://lava.net/~newsham/x/conv2.c

For example:

    conv2 -o myfile.tap src.tar

to put "src.tar" onto the tape.

> But I have one more urgent question. The Unix V7 image for PDP11 comes
> with tty, tty1 and tty2 terminals defined... but NOT in /etc/ttys. In
> fact, when you add these terminals to /etc/ttys and go multiuser with
> ctrl-d the system give a trap and stops. Someone knows how to put them
> to work ?  did some probes with VH and DZ with bad luck.

It's been a few months, but if I remember correctly the extra tty
hardware in simh (dz?) is not supported by v7.  There was a driver
in v7 but it has some comments to the effect that the driver is
not in working order.  I stuck to using the console.

As far as getting a trap when going multiuser, I was able to
boot multiuser just fine.

> Sergio

Tim N.