[Simh] Standalone boot on vax8600?

[Mark Pizzolato - Info Comm]

On Thursday, July 10, 2014 at 3:13 PM, Cory Smelosky wrote:
> On Thu, 10 Jul 2014, Henry Bent wrote:
> 
> > Well, that at least did something different.
> >
> > sim> boot rq0 /r5:8
> > Loading boot code from vmb.exe
> > %BOOT-F-Unexpected Exceptio
> >
> > The 8600 simulator always seems to cut off the last character of its
> > messages, I wonder if that's in any way related to the other console
> > problems.
> >
> 
> 780, 750, and 730 have the same issue...along with not actually booting from
> the console RL, floppy, et al.

The last character output in a message just prior to executing a HALT instruction is not surprising since the simulator implements a delay (as a number of instructions executed) from when the data is put in the output register prior to generating the completion interrupt/status.  The halt instruction gets executed before the delay number of instructions have completed.  Even if that was 'fixed', nothing operational would change.  The reason the message has been generated will still exist.

As for direct support for booting an OS from the console media, the 8600 supports BOOT CS /R5:xx to boot from the console RL02.  Other than that, VMB.EXE is actually performing the boot operation and I think that when I checked VMB didn't know how to boot from console floppies on a 780, but it can boot from the console TU58 on both the 730 and 750 (BOOT TD /R5:xx).

> > I tried the standalone boot on the other VAX sims (microvax 1, 2,
> > 3900, and
> > rtvax1000) and they are all able to load the booter and take console
> > input (I didn't actually try booting).  This seems to point to there
> > being a problem with the console on the 8600.  Any tips for where I
> > should look to narrow down where the problem might be?

What media have you tested with on the other (qbus) VAX simulators?

- Mark