uVAX II Memory Board

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sat Feb 3 13:11:35 2001

>Dave McGuire wrote:

> On February 2, Jerome Fine wrote:
> > course if the Pentium had been around 10 years sooner, maybe DEC
> > would have made a better PDP-11.
> Oh good lord. That's a troll for flamage if I've ever read one. A
> good one though; I almost cut loose on you for it with about ten pages
> about why this is full of doodoo. ;)

Jerome Fine replies:

If I remember correctly, the Pentium came out around 1993, about four
years after the 486 came out around 1989. If the engineering, design and
technical capability that led to the Pentium had been around in 1980, the
technical superiority that the PDP-11 enjoyed over the PC might have
pushed DEC hard enough to upgrade the PDP-11 systems.

Consider that the VAX can't be purchased any longer as a new system
while it is still possible to purchase a new PDP-11. Of course, I do
understand that the primary OS for a VAX is VMS and that since the
Alpha outperforms the VAX, it is no longer reasonable to purchase
a new VAX as opposed to the Alpha - so to a very large extent, the
reason for the lack of a new VAX as compared to a new PDP-11
is understandable. But the point I think is lacking in this aspect of the
discussion is that DEC is not the company that is building and selling
these new PDP-11 systems. And consider further that it is less
expensive to run the E11 emulator on a PC and faster than any
current hardware PDP-11 solution - if you are comparing systems
with similar throughput or similar price, especially for hobby users.

For commercial systems, operation at the high end can also be
compared in favour of E11. With a fast Pentium III and E11,
running PDP-11 software is less expensive and faster than with
the fastest PDP-11 hardware.

Now all of the above observations and speculation is far in the past
as to why DEC stopped competing with the PDP-11 hardware
and software. So as someone who runs some PDP-11 code
almost every day, I just accept that DEC is no longer around.
Maybe, even all PDP-11 OSs might end up in the Public Domain
by the next century, although at the present time, there still seems
to be some profit in the software.

But back to my original question and Zane's response plus the low
price of memory. Might it be possible to design and produce a
Qbus board which uses memory as the disk and have an interface
like the HD: on E11 rather than MSCP? Considering that from
the lack of a response on my original question in regard to the
use of the 8 MByte of memory, it may be just as easy to start
from scratch. By the way, on the "Full" commercial E11, the
command is: "MOUNT HD0: RAM:/SIZE:bytes"
and HD0: can be replaced by any of the emulated drives as well.

Sincerely yours,

Jerome Fine
Received on Sat Feb 03 2001 - 13:11:35 GMT