VAX-11/780 boot disk

From: Clint Wolff <>
Date: Tue Jan 23 20:52:54 2001

Hi Richard,

On Tue, 23 Jan 2001, Richard W. Schauer wrote:

> Hi everybody-
> I just recently acquired a whole bunch of stuff out of a company's
> basement, including a VAX-11/780, VAX-11/750, 4 RA81's, a TU80, a
> pdp-11/44, 4 RL02's, an RP06, a TS11, and spare parts and printsets
> galore.

Lucky B******D... Nobody in denver has a basement full of neat stuff
like that... cept Will... (haven't forgotten the 11/34 printset yet)
> (Yes, John Foust, the little pdp-11/44 in Milwaukee led to all
> that.) All the equipment was brought up a flight of carpeted stairs by a
> refrigerator dolly and human power, except the RP06 and the 780 where we
> used a come-along and a lifting frame I made. Heavy!

Cool... I'm planning on moving my '780 into the basement with the same

> Anyway, the 780 needs a floppy to boot. The previous owner says he
> doesn't have it, and I can't find it (although I'm not done searching
> yet).

I have at least one (in the machine), but it may be bad... I bought one
from ebay, but again, it may be bad... I need a quick way to hook an
8" floppy up to a running computer to read it...

Anyone know if I can plug an RX01 drive & QBus controller into a uVAX II?

> Is this the sort of thing that is generically available, on the WWW
> for instance, or is it something that is built up specifically for the mix
> of options I have in the machine?

I haven't found anyplace yet, and once my toilet stops leaking (long
story), I'll be putting together 780 & 750 software and paperware on
a website...

> Incidentally, does anyone here that has a 780 (I know there are several in
> the group) run theirs? It takes 3 phase power, but there are no loads
> connected phase-to-phase, only phase-to-neutral (although there is a small
> 3-phase transformer in the power controller, it could probably be wired to
> only use one phase or else bypassed completely) so it can run entirely on
> 110 volts, at about 60-70 amps continuous draw. I was thinking of using
> split-phase 220, putting 2 phases on one hot and 1 on the other, then
> putting the Unibus cabinet and disk and tape drives on the hot with only 1
> phase on it. I figure this would about balance the draw at 40 amps, 220
> volts, which isn't too unreasonable.

There is a single unregulated 25V supply (unknown current) which runs off
a three phase x-former... This supply is then regulated down to +15V to
run the airflow and temp switches, and also a 12mA(?) current source for
some reason which escapes me... I think you should disconnect the
three phase transformer before hooking up two phases to the same hot...

My plan is to just set up a new 25V unregulated supply once I figure
out how much current it needs to supply...

> Richard Schauer
Received on Tue Jan 23 2001 - 20:52:54 GMT

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