[Simh] Re: Simh Digest, Vol 7, Issue 2

[petervdbos at zonnet.nl]

Hi all,

As I remember well about the 750 having serviced these machines when I 
worked for Digital at that time, the 750 processor did the console 
emulation as well. I know for sure because one time I entered Control-P 
which stopped the VAX 750 immediately! (Customer was not happy :-) The 780 
had a PDP 11/03 as a console.

Peter



Citeren Ethan Dicks <dickset at amanda.spole.gov>:

> On Mon, Jun 14, 2004 at 04:40:39PM +0000, bsupnik at comcast.net wrote:
> > 1. Older VAXen.
> > 
> > A 780 or 750 would require substantial changes to the simulator; indeed,
> it
> > would be almost an entirely new simulator.  In particular,
> > 
> > - the CPU must support all the VAX instructions, not just the VAX 
subset.
>  That
> > includes decimal, obsolete character string, H_floating, and EDITPC
> (argh!) 
> 
> Compatibility mode?
> 
> > - the boot and console protocol is based on an external microprocessor. 
> While
> > that doesn't have to be explicitly emulated, all the proper firmware has
> to be
> > found.
> 
> While the 11/780 and 11/730 had an external console and boot processor, I
> don't
> recall seeing one in the 11/750.  Is it embedded on the console board? 
> Certainly,
> the 11/780 and 11/730 were always soft-loaded, and the 11/750 normally 
came
> up
> on its own read-only WCS memory that could be boot-time or run-time
> patched.
> 
> Not to say it's easy or not easy, just recollecting what I can of those
> machines.
> 
> Disclaimer: I've owned KA750 and KA730 machines, and I've only had
> user-level
> access on 11/780-class machines.
> 
> I, too, would like to see an emulator for the older hardware, but I can
> see
> how much harder that is than emulating a CVAX chip.
> 
> -ethan
> 
> -- 
> Ethan Dicks, A-130-S      Current South Pole Weather at 15-Jun-2004 10:20
> Z
> South Pole Station
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> ft)
> 
> Ethan.Dicks at amanda.spole.gov    
> http://penguincentral.com/penguincentral.html
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