VAXen at home - test-drb@ccmp.vtda.org

15 Oct 2007

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Subject: VAXen at home
   From: ard at p850ug1.demon.co.uk (Tony Duell)
   Date: Mon, 15 Oct 2007 23:21:05 +0100 (BST)
     To: cctalk at classiccmp.org

   So you
want me to start off with a VAX?  
 Lots of folks on this list have lots of nice things to say about the 11/750. 
Personally, I theink the 11/750 is not the best machine to try to keep 
running. The reason is that the CPU is made up of a large-ish number of 
custom gate array chips. Even when they were available as spares from DEC 
they were very expensive, now they're unobtainanle other than by raiding 
other 750s. 
It's not that bad, lots of spares out there this side of the pond.
It's a nice system as it's fast enough to be useful and while a 
big VAX it's not a huge vax like 780 or 8650. That and there were
a fair number of machines kept in service that were supported.

...
 If you have the space (and it's large), try to get
am 11/780. I've never 
been inside one, but I've read the printset (schematics) and it seems to 
be all standard chips.  
The air handlers and the power will get you.  It's a very nice well
ordered machine in many ways. 

...
 If you don't have the spave, and can stand the lack
of speed, consider an 
11/730. It's small (1 10.5" high rackmount unit), you can fit the 
processor, disk and tape drives into a half-height rack (this was a 
standard configuration). It's almost all standard chips, 2901 ALUs, TTL, 
non-protected PALs, etc. 
The only thing is a 730 is hard to expand to run fairly current VMS
and it's slow.  For that performance you can get a lot of other VAXen.
It's up side is for one rack it's small and power consumption is
within the realm of a 20A at 120V circuit with some of the smaller
single cab version down near 12-13A at 120V.

Allison