Subject: Re: VAX-11/750 matters
To: None <>
From: Kees Stravers <>
List: port-vax
Date: 06/09/1998 12:29:44
The 750 itself isn't too picky, it'll work (in my experience) with
the temperature being between 15 and 30 celcius. Mind that it will add
to the room temperature significantly! I had my 750 in a very small room 
once, where it just fit in, and in one hour the temperature had risen
10 degrees. The heating bill will definately go down if you leave the 
750 on 24/7. I don't know which hard disk you have, but a RA81 is a bit
more sensitive to low temperatures, it wants around 20 celcius to be happy.
Normal living room conditions are fine. You will also notice the 750 is 
fairly noisy.

 fs>And, how about supplying power? Is a 10A fuse
 fs>enough, we have 220V voltage here? 

I am afraid 10 amps is very close to the edge, though it depends on
the hard disk. The 750 will use about 8 amps if the max amount of cards 
is installed, which is unusual. But: a RA81 uses about 18 amps to start 
up, 3.5 amps while running. A normal fuse used in home installations can 
for a short while deliver twice the rated amount, the short while being 
long enough for the disk to start up.
When I had the 750 and the RA81 both on the same group, the fuse blew
at once when I started the disk. I have used the RA81 on one group and
the 750 on another since then, so each had its own fuse. The fuses in 
my home are 16A. This still means that using the oven was forbidden while
the 750 was on :)

 fs>This system will run NetBSD
 fs>afaik, so if I just manage to make a install tape somewhere, I'll
 fs>get it up and running. 

This is not going to be easy. The 750 can only boot from a hard disk or
from the little TU58 tape drive in the front of the machine. It cannot
boot from the nine track reel to reel tape drive. The capacity of TU58
tapes is low. Ragge once created an install set, and there were nine
tapes needed for the miniroot. NetBSD can only read TU58, so creating
those tapes will have to be done with a system running VMS. TU58 is a bit
unreliable, so if you do create those tapes, verify them carefully!

 fs>Are there some other obscure things
 fs>about positioning the machine that I should be aware of?

If you can walk around it, to plug cables in the back etc. then it is
positioned just fine. Don't shove it against the wall, leave a little 



Kees Stravers - Geldrop, The Netherlands - pb0aia at amsat dot org
Sysadmin and DEC PDP/VAX preservationist -

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