DEC Scrounging & SWTPC 6800 Update

From: Anthony Clifton <wirehead_at_retrocomputing.com>
Date: Fri Sep 5 13:59:35 1997

Uhhhh...was it my deodorant?

=-)

Anthony Clifton - WireHead Prime

On Fri, 5 Sep 1997, Faiaz, Michael C. HSD wrote:

> unsubscribe
>
> ----------
> From: Anthony Clifton
> To: Discussion re-collecting of classic computers
> Subject: Re: DEC Scrounging & SWTPC 6800 Update
> Date: Thursday, September 04, 1997 5:21PM
>
>
>
> (BTW, I'm going to leave this thread public because I think it might
> be of interest to collectors new to the PDP series and who might run
> across machines like this.)
>
> > > An 11/84 CPU alone apparently pulls 1100 watts
> >
> > A *fully-loaded* 10.5" 11/84 box will pull 1100 watts. A very much
> > reduced configuration - just a CPU, memory, and (non KDA50) disk
> controller
> > - will only draw 100 watts or so.
> >
> Well the backplane looked about half full roughly. So this is sounding
> a bit more hopeful. I have $10 a month to spend on this machine for
> electricity at about 8 cents per kilowatt hour so....
>
> > I believe the spec for the RA-80 spinup surge current is 40 Amps. While
> > running, it's probably about 7 amps.
> >
> I didn't have ALOT of time to look the machine over but I did look in
> the
> back of the cabinet containing the TU80 and the RA80 and saw a sticker
> that said "30 amps" which I ASSUMED referred to the RA80. I only ever
> owned RL and RK series drives when I was collecting PDPs in the early
> 90s...what are the size etc specs on the RA80? A friend of mine and I
> built an 11/34 system with 2 or 3 RK series drives and an older model
> DEC 9 track drive. So I'm not completely ignorant but I'm still getting
> used to the CURRENT state of the art in throwaway PDPs.
>
> > A TU80 doesn't take much; about 50 watts with power off, and less than
> > 200 watts with the blower and reels running.
> >
> Aha! This IS sounding alot more hopeful. Basically, if I could come up
> with a controller to drive modern SCSI drives or something a bit less
> power hungry, I could probably afford to run this guy at least all
> weekend
> every weekend or something like that. Hmmm...I wonder if there's any
> market for converting 9 track media to more modern forms? It'd only
> take $60.00 a month, with modern drives, to run the beastie 24 hours...
> perhaps less. =-)
>
> > (presumably) is in the 11/84 will also talk to RA7n's and RA9n's. With
> > a Emulex/CMD/Dilog ESDI or SCSI controller in the box, you can even hook
> > up perfectly modern 3.5" hard drives.
> >
> Hmmmm...what's strange is that they claim they upgraded the drive around
> two years ago. Upgrading TO an RA80 seems a bit strange in 1995. But
> the
> front of the drive said RA80 so....
>
> > > Now for my request, if anyone has schematics or technical drawings of
> this
> >
> > What do you specifically need? A print set for a complete configuration
> > is several hundred 11x17" sheets...
>
> Sheesh. I guess that's true...the print set for my old 34 was several
> 'books' of many pages a piece if I recall correctly. Ummm...if anyone
> has the print set for an 11/84 they'd like to go to a good home then
> let me know. =-) (If not, I'll probably run across one one of these
> days.)
>
> The machine DOES work apparently and the guy who operated it showed it
> to
> me today. He claims that it worked fine when they shut it down 2 years
> ago (yeah yeah I know) and it's just been sitting in the corner since
> then. He claims that if I plugged it in, which I didn't have an
> opportunity to do, it would come right up into RSX. We'll see after
> next week. One other obstacle is that it all has the funky twisty
> safety
> plugs on the AC cords but it's configured for 125 v etc so I'll replace
> the plugs, like I did on my 34, with high quality normal ones.
>
> Anthony Clifton - WireHead Prime
>
Received on Fri Sep 05 1997 - 13:59:35 BST