RL02 version of UNIX6?

william degnan billdegnan at gmail.com
Thu Feb 2 22:19:59 CST 2017

On Thu, Feb 2, 2017 at 11:06 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

>     > From: Allison
>     > for laughs I wandered over to:
>     > http://ftp.math.utah.edu/pub/mirrors/minnie.tuhs.org/PDP-
> 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.


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