Date: Thu, 2 Apr 1998 23:50:23 -0800 (PST)
From: "Steven M. Schultz" <sms@moe.2bsd.com>
Message-Id: <199804030750.XAA10664@moe.2bsd.com>
To: grog@lemis.com, shoppa@alph02.triumf.ca, wkt@CS.ADFA.OZ.au
Subject: Re: Bug in Bob Supnik's Emulator!
Cc: pups@minnie.cs.adfa.oz.au
Sender: owner-pups@minnie.cs.adfa.oz.au
Precedence: bulk

Greg -

> FWIW, I've used the latest (and not yet committed) version of the
> Begemot emulator to run 2.11BSD for over a week.  In that time, I

	AH, a new and improved version?  Great!  SOmething to look forward to.

> unexplained problems with the assembler, which Steven Schultz
> considers to be due to the emulator (more specifically, instruction
> restart), but Hartmut Brandt (the principal author) thinks this is unlikely.

	It was a possibility - the only other thing which I've seen cause
	similar problems was bad memory/cache.  I presumed your memory
	wasn't failing ;).

	Programs suddenly dying for no apparent reason on otherwise healthy 
	"hardware" led me to suspect a problem with the emulator.  The final
	arbiter of course is a real PDP-11 :)

	I take it then that the problems went away as mysteriously as they
	arrived and that all is well with your system (no more assembler
	or kernel recompile troubles)?

	Not having any great need of an emulated PDP-11 I've not pursued
	the (suspected) bug in Bob Supnik's emulator.  Even on a PentiumPro
	an emulated 11 is slower than a real 11/73 (and a lot slower than an
	11/93 - which I should cease neglecting and stuff a SCSI card into
	some day as I did with the 11/73).

	Steven