Newsgroups: alt.folklore.computers
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Y VAX? [was : TECO on a DEC-System 10]
Message-ID: <1990Jan18.193530.22427@utzoo.uucp>
Organization: U of Toronto Zoology
References: <153.UUL1.3#5131@mvac23.UUCP> <457@ns-mx.uiowa.edu>
Date: Thu, 18 Jan 90 19:35:30 GMT

In article <457@ns-mx.uiowa.edu> jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) writes:
>                         (the 11/15 was the OEM version of the 11/20?)

Correct.

>                         (the 11/40 was the OEM version of the 11/45?)

Nope, quite unrelated.  (The 45's number has always been a bit of a
mystery.)  The 40 was a cheaper, slower, cut-down 45 -- the new "mid-range"
model to replace the 20 -- and originated the brain-dead low-end version
of the MMU.

>                         (the 11/35 and 11/30 were introduced later?)

The 35 was an OEM 40.  Never heard of a 30.

>    PDP-11/70  -- as I understand it, this was basically a PDP-11/45
>                    CPU with an expanded segmented memory mapping
>                    architecture and something other than the UNIBUS
>                    to connect the CPU and main memory.

There was a 45 hiding inside, but the MMU was new (faster as well as
wider), there was a cache, there was a wider memory bus, and there
were provisions for fast I/O devices going direct into memory without
going through the Unibus.  (These were often referred to as "Massbus"
devices, but technically the Massbus was DEC's odd controller-to-peripheral
bus rather than the controller-to-memory bus.)

>                         (the 11/05 was at about the same time?)

No, the 05 and the 45 were simultaneous -- 05 at low end, 45 at high end.

>    PDP-11/78  -- a paper machine, intended to outperform the 11/70,
>                    with improved support for 32 bit operands.

There were also several 11/7x models, never released, that were basically
multiprocessor 70s.
-- 
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu