4 Dec
2015
4 Dec
'15
12:46 a.m.
Noel,
Thank you for writing and responding to my writeup. I have replied
inline, below:
On 12/3/15 9:21 AM, Noel Chiappa wrote:
Thanks for reminding me about your work. I had scanned it briefly when I
was first starting down this road, but wrote it off because I wasn't
using the Ersatz11 simulator. With the background I have now, it should
be translate into my current frame and be useful. I haven't tried
tackling the time problem yet, but I will keep your document in mind
along with Wolfgang's fixes for ctime:
http://www.tuhs.org/Archive/PDP-11/Bug_Fixes/V6enb/
Oops. I will be more careful in how I refer to the PDP-11
from now on.
This is a duh moment for me. I will change
the note to reflect testing
first, then copy over.
I have since learned a lot more about this and will update the note.
Regards,
Will
From: Will
Senn <will.senn(a)gmail.com>
I am studying Unix v6 using SimH and I am
documenting the process
I did a very similar exercise using the Ersatz11 simulator; I have a lot
of stuff about the process here:
http://www.chiappa.net/~jnc/tech/V6Unix.html
the PDP architecture
Technically, a PDP-11 ... The only differences I could discover between the two
are that in the Wellsch
versions i) a Western Electric rights notice (which prints on booting) has
been added to ken/main.c, and the Unix bootable images; and ii) the RK pack
images do have, as you noted, the bootstrap in block 0.
Thanks for this. I will
update my note appropriately.
Note: sh is
critically important, don't muck it up :). The issue is
that if you do, there really isn't an easy way to recover.
One should _never_ install a new shell version as '/bin/sh' until it has been
run and tested for a while (for the exact reason you mention). Happily, in
Unix, as far as the OS is concerned, the command interpreter is just another
program, so it's trivial to name a new binary of the shell 'nsh' or
something, and run that for a while to make sure it's working OK, before
installing it as '/bin/sh'. a special file (whatever that is)
Special files are UNIXisms for 'devices'. _All_ devices in Unix appear as
'special files' in the file system, usually (but not necessarily) in /dev -
that location is a convention, not a requirment of the OS.