16 Nov
2005
16 Nov
'05
2:57 p.m.
Subject: RE: DEC "Junk" rescued
From: Paul Koning <pkoning at equallogic.com>
Date: Wed, 16 Nov 2005 09:33:03 -0500
To: cctalk at classiccmp.org
Funny thing about PDP-11 system models. Even number for the most part
are unibus like 11/34 or 11/44 (11/05, 11/35 exception) and odd number
like 11/03, 11/23 are qbus.
I&D for Chipset CPUs didn't start untill the J-11. The F11 gave us
user/system register sets and the MMU. The unibus J11 was the 11/84
I believe.
F11 machines are a good workhorse 11s. As far as my data goes all of
the chip (F11 and J11) cpus on unibus are faster by some amount as
there isn't the multiplxed address/data bus transaction. Though I
believe the real reason was to preserve the unibus IO investment
and generally higher IO transaction rate that unibus devices enjoyed.
Allison
>>>> "Allison" == Allison
<ajp166 at bellatlantic.net> writes:
Allison> I thought the 11/24 was the 11/23 chipset (F-11) mated to
Allison> Unibus rather than the Qbus.
Correct.
> 11/24 is split I&D UNIBUS, right?
Nope...
paul