9 Dec
2005
9 Dec
'05
6:46 p.m.
Subject: VS2000 speed (was RE: A Hobbyist DECnet Network)
From: "Robert Armstrong" <bob at jfcl.com>
Date: Fri, 09 Dec 2005 10:24:55 -0800
To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk
at classiccmp.org>
Nope. the SMC9224 part did have DMA. It didn't have the ability to DMA
further than 16mbytes. It was the MSPC translation to that part that was
painful. It also had SCSI via the NCR5380, but since SCSI was not yet
a standard it doesnt talk to anything useful (OK, other than the TK50).
the lack of T11 was less a hit than lack of the implied buffering it
gave. The uVAX-II was not that much faster in booting.
Oh if you had less than 8mb ram the swapping was very painful!!! And most
only had 2M or 4m.
The VS2k is a bare bones uVAX-II cpu and inst
very fast but I never
thought the boot to be unusually slow unless the dianogstic
were running.
RD5x drives are painfully slow, and this is especially a problem in the
VS2000 because the integrated disk controller a) lacks DMA, and b) lacks the
T11 chip to do local processing found in a RQDXn - the uVAX CPU has to do
all the work. Starting DECwindows, especially, took forever...
[Also, maybe I can cook dinner faster than you :-)]
Bob
Nah, I order out. Standard programming foods, PIZZA! ;)
Allison