[Info-vax] RB730 Integrated Disk Controller (R80/RL02) usable with VAX-11/750?

[SeanOBanion]

On May 3, 9:38 am, SeanOBanion <s... at obanion.us> wrote:
> On May 2, 9:59 pm, Johnny Billquist <b... at softjar.se> wrote:
>
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> > On 2011-05-02 17:05, SeanOBanion wrote:
>
> > > On May 2, 2:52 am, vaxorcist<vaxorc... at googlemail.com>  wrote:
> > >> Can the RB730 Integrated Disk Controller (primarily developed for R80/
> > >> RL02 drives with the VAX-11/730 and /725) be used with the VAX-11/750?
> > >> This might have been a "low cost" solution to connect disk drives to
> > >> the /750.
>
> > >> Any hints welcome!
>
> > >> Regards,
>
> > >> Ulli
>
> > > No.
>
> > > The IDC is part of the 730 CPU, stealling CPU cycles in a hidden way
> > > to get it's work done.
>
> > Cute. I have never examined the IDC in detail... :-)
>
> > > The later version of the 730 did away with the IDC for a single UDA50
> > > Unibus adapter that also reduced the amount of memory the system could
> > > support:
> > > system memeory of a 730 sat on the Unibus.
>
> > What??? Are you sure? The Unibus only have 18 address lines, which means
> > 256K addressable. And some of that is needed for I/O. I would be very
> > surprised if memory really sat on the Unibus.
>
> >         Johnny
>
> > --
> > Johnny Billquist                  || "I'm on a bus
> >                                    ||  on a psychedelic trip
> > email: b... at softjar.se             ||  Reading murder books
> > pdp is alive!                     ||  tryin' to stay hip" - B. Idol- Hide quoted text -
>
> > - Show quoted text -
>
> Yes, I'm sure.
>
> My university bought a new 730 while I was there, and added a TU80
> tape drive to the original R80/RL02 (along with the butilin TU58...),
> and the system had the IDC and a DMZ32 serial  / parallel interface (8
> or 16 lines, and a Centronics interface) already installed.
>
> The TZ11 tape interface  (though it must have been called something
> else but it was really a TZ11...) had to go in a Unibus expansion box
> in the TU80 enclosure.  Along the way, the Unibus expansion cable from
> the CPU to the TU80 encllosure, a white flat "ribbon" cable of bare
> copper wires between a pair of platic sheets held in place a strategic
> locations with foam, got a broken wire.  The FE was soldering  jumpers
> on the memory card (cards?) and talking about how it (the memory card)
> could be generating errors on the Unibus.  After getting bus errors at
> an address higher the memory addresses, he concluded it was the cable
> and brought a new one in the next day.- Hide quoted text -
>
> - Show quoted text -

Also see doc's in:
http://www.bitsavers.org/pdf/dec/vax/730/