On Thu, Feb 2, 2017 at 11:06 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:
From: Allison
11/Boot_Images/
To see if the copy of V6 on RL02 is still
there.... yep it is. and
it
runs on a 11/23 just fine
Yes, that's another copy of the Shoppa disk.
So, I looked at that system, to see how it dealt with the clock issue on an
11/23 (in /sys/ken/main.c, if anyone else is interested). While looking, I
noticed something that made it extremely unlikely that it would boot on an
11/40. Sure enough, attempting to boot the /unix on it on a (simulated)
-11/40
blows out.
There are a couple of other unix loads on that pack image (oldunix,
unix.tmp,
etc), but all the ones I looked at had the same issue (only tried booting
the
'unix' one, though); they're probably all for the same machine, so have the
same configuration issue.
V6 Unix was pretty persnickety about the hardware configuration it ran on;
while it was possible to create builds that would run on almost any
configuration, on 'vanilla' V6 that really only applies to the /40/45/70
era. And even then you still had to re-build the system to match your
actual
hardware configuration, almost all the time.
The advent of the /23 (with no CSW, and no KW11-L/P), made things more
complicated. (The clock is pretty key - Unix needs one - several things,
e.g. parts of the teletype drivers, require real-time delays provided by
the
clock. I've never tried to run Unix without a working clock, I'm not sure
if
it would run without slowly grinding to a halt as stuff waited for clocks
delays that never happened.(
With a little work, a suite of 'universal boot' versions (one for each
type of
disk controller - RK05/RL02/RX02 etc) could have been created that would
boot
and run on any pretty much CPU/etc configuration - at least, well enough to
build one that did exactly match the hardware configuration at hand. (The
one
on the Shoppa disk is close, from what I could see.)
I don't think anyone ever bothered, though (in part because it was much
more
of a PITA to test them all, BITD, with only real hardware).
Noel
Well I must say my focus has been on just getting an 11/40 hardware working
enough to be a candidate for any flavor of UNIX, then figure out the
details, but this thread has been an education. I suppose I should be
happy with RT-11 given my circumstances.
Too bad I have not been able to get my EIS running. I tried a number of
things so far. I may have to shot gun approach the caps and such in an
effort to repair. It's not possible with the 3 over the back cables to put
the 7238 on a riser card to probe signals as easily. I have downloaded the
docs associated with this card.
Also, following your directions I had no issues getting V5 and V7 running
in simH.
I am curious to see what OS's run on an 11/40 without the EIS card other
than RT-11. I am researching this. I have always wanted to learn more
about batch-11.
b