11 Jun
2009
11 Jun
'09
1:14 p.m.
On Thu, Jun 11, 2009 at 3:51 PM, Kirn Gill<segin2005 at gmail.com> wrote:
If you were to attempt to run a full virtualization
engine on, e.g., a
486DX2, the guest would probably run so slow that you could debug each
executed instruction in real-time.
Years and years ago, when simh first broke onto the scene, my "fast"
machine was a SPARC1 (20Mhz/12 MIPS) w/64MB of memory. One of the
first things I loaded up, since I had real tapes on hand, was 2.9BSD.
It was quite a bit slower than a real PDP-11, but I didn't have any
real PDP-11 disks over 10MB, so the virtual environment was "better"
because I could allocate 40MB of my 1.8GB disk to hold the guest OS.
Fortunately, when I was debugging a problem with the RP module, I had
moved up to a SPARC5 which ran a virtual PDP-11 faster than the real
thing. Given how many times I rebooted the virtual PDP-11, I was very
happy to be doing this on a faster platform.
Speed isn't everything, but it sure is nice when you can get it.
-ethan