Subject: RE: My first step towards a VAX 11/785 :-)
To: 'Gunther Schadow' <>
From: Carlini, Antonio <>
List: port-vax
Date: 07/10/2001 05:19:37
Gunther Schadow wrote:

> Sunday I found five large boxes in front of my house. Got 56 cards
> ready to put into a 11/785 cabinet. What surprized me is how different
> these cards look and feel from the VAX 6400 cards. They are larger

The VAx-11/785 is essentially a VAX-11/780 (except faster)
so it's really design that first shipped in 1978.

The VAX 6000-400 is (construction-wise) basically a design
that first shipped in 1988 (when the VAX 6000-200 shipped).

Over those 10 years, the level of integration (i.e. the
number of transistors that could be stuffed in a chip 
plus the sophistication of the chip design tools) increased

So the 20-odd boards that make up a VAX-11/78x
CPU + FPA + system bus interface became condensed 
into just one board 9per CPU).

Memory desnity went way up too!

> in size, yet thinner, and lighter in weight. Also the chips on the
> cards look much less impressive than the VAX6400 chips. Looks like 

The chips are mostly TTL on the VAX-11/78x but are almost
all VLSI custom chips (and probably all SMT too) on
the VAX 6000-400.

> all small 10 to 20 pin TTL DIL style ICs. Is that right? Why am I 
> missing a set of larger square ICs holding CPU etc? Is this because
> the 11/780 isn't a microprocessor machine but rather several boards
> per CPU with a printed circuit for what's usually engraved in 
> silicone?

The VAX-11/78x CPU is indeed a multi-board set.