BAR register? What does the qbus have to do with a Browning Automatic
Rifle???
_________________________________________________________________
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The purple is a Xerox 6085 and the white one is a 8010. Nice machines. You
need the matching monitor and keyboard.
The 6085 monitor has two cables on it and a power cord. This along with the
Xerox makes them easy to identify. You need the monitor and keyboard to make
either the 6085s and 8010s to work. The 8010 keyboard is fat and the 6085 is
thin and has a 6 or 8 pin RJ type connector. IIRC both have either 8 or 10
large function keys at the top.
Both systems are worth saving. I think I have a set of Viewpoint 2 for the
6085s (5 1/4" disks) in storage. I keep hoping I will find another myself.
Paxton
Portland, OR
From: Ken Seefried <ken(a)seefried.com>
>Forgive me if this is a silly question; it never got covered in my
digital
>electronics classes :-).
>
>Is a modern switching power supply a suitable replacement for an ancient
>(and dead) linear power supply in a classic computer (PDP-11, FWIW)?
First switch mode vs linear only covers HOW the regulation is obtained in
a power supply unit.
Most of the DEC PDP-11s had switch mode supplies especially the Qbus
PDP-11s though many of the later Unibus systems did as well.
The problem using a PC supply is that DEC supplies provide DCok and
BeventL (line time clock) to name a few signals plus the +12 and -12
power may exceed most PC PSUs. the later is something for a case
by case study.
I have used a 200W PC supply (it was handy) to run a 12 slot H9281-AC
with 10 cards in it. I had to supply DCok and Bevent-L, it was otherwise
ok.
Allison
Forgive me if this is a silly question; it never got covered in my digital
electronics classes :-).
Is a modern switching power supply a suitable replacement for an ancient
(and dead) linear power supply in a classic computer (PDP-11, FWIW)?
Ken
On May 12, 14:14, ajp166 wrote:
> What your havent tried is differnt controllers and different drives.
>
> I found an old 486 or 386 machine to be less troublesome and also
> has fewer preconceived notions of the world. Also I ran dos not
> windows(any version)!
>
> I was able to make Venix disks for my Pro many years ago and also
> OS278 (also rx50). What I had to do however was to play with the
> jumpers on a TEAC FD55GFV (the verseion with many jumpers)
> to lock out the 1.2mb mode.
Which leads me to think about a tangentially-related problem -- I recall
that some FDCs insist upon the index mark at the start of the track, and
some don't, but I can't remember which FDCs do/don't (I think WD 37C65 etc
need it but NatSemi DP8473 and WD 1770/1772 don't care).
Also, I recall that some FDCs are more likely to work with 8" drives than
others, and some are more likely to work at single density than others (at
least, some PC ISA controllers are unlikely to work at SD because the
relevant components are not there). I want to set up a PC to use with 8"
drives, including single density, mostly with 22DISK. I have a choice of
386/486/Pentium motherboards, and a selection of ISA controllers, with an
assortment of 765, 8272, 37C65, and 8473 FDCs (I haven't checked, but I'm
pretty sure I have at least one of each). What is most likely to work?
--
Pete Peter Turnbull
Network Manager
University of York
On 12 May 2001, Iggy Drougge wrote:
> >Silly argument, but I'll humor you by saying they would at least be highly
> >collectable (and highly valued), as they were used to paint the Mona Lisa.
> >Are you starting to see the connection here?
>
> Of course they would be highly valued, but my point is not whether they are,
> but whether they should.
You say "of course they would be highly valued" then as whether they
should. That's for you to decide. I would highly value them.
> >Abstractly, yes. The original is a tangible product of the man, hence
> >it's value relative to copies.
>
> Are copies less tangible?
No, but they don't offer a direct connection to Da Vinci. I would prefer
something Da Vinci himself had a hand in creating rather than some 3rd
rate art school schlub, or even a 1st rate renowned painter (unless I
happen to be fond of the 3rd rate schlub or the 1st rate painter).
Again, the connection is with the creator. And you've been arguing this
for so long now that you've forgotten that we are not judging the work in
and of itself. The work stands alone for judgement whether it be an old
computer or a painting. But the original was a direct part of someone's
life, and in that regard it is "tangible", whereas a new reproduction or
copy is not (not tangible to anyone elses life besides now your own).
> >> But of course it can! It's built from the same plans and offers the
> >> same functionality.
>
> >And it has all the historical significance that everything "Made in
> >Taiwan" has. Yes, of course!
>
> It doesn't matter whether it's built in Taiwan or the Czech republic
> as long as it's according to the plans.
And if all you're after is functionality then your point is well taken.
However, if you're after historical context then the original is obviously
preferred.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
From: Chuck McManis <cmcmanis(a)mcmanis.com>
>Bus Address Register (puts this address on the Bus) and yes there are
two
>more bits in the CSR for XAD16 and XAD17 to tell it the upper two bits
of
>the address (16 + 2 = 18) but no word on if there are four more bits
>squirrelled around somewhere to do it right for the 22 bit back planes.
I
Nope only 18bit. Thats an old card.
>Another idea I had was to hook up perhaps some M7941s to some solenoids,
>light bulbs, etc and have the local high school kids see what sort of
>effects they can create.
Yes, good appication. or a matrix of leds and switches for a simple
game.
Allison
Well, wandering through my handbook collection for something that might be
interesting I came across the Microcomputer Products Handbook from 1985.
This is a 'Q-bus products overview' book. And lo' and behold we find the
tech sheet for the DRV11-WA which is the replacement for the mature DRV11-B.
That being said, I'm now on the hunt for DEC document EK-DRVWA-UG the
DRV11-WA Users Guide. I'll happily trade a DELQUA users guide or a DHV11
users guide for it.
I even found a cab kit for it in my box of misc cab kits. What I haven't
yet figured out is how it DMAs into a 22bit address space with a 16 bit Bus
Address register. Perhaps there are some bits in the CSR to set bits 18
through 21.
In processing a google search I discovered that the DECUS.org archives are
now not where they used to be (I couldn't find them easily)
Perhaps the coolest thing I've seen so far is that you can almost use this
thing to create a front panel for an LSI-11 system. You can certainly
deposit and examine memory and start and stop the processor :-)
--Chuck
From: Richard Erlacher <edick(a)idcomm.com>
>I didn't know it was practical to use mass storage devices under VMS
without
>using the MSCP. Gee ... I didn't think I'd ever learn anything more
about DEC
MSCP was not the only mass storage interface. IT was most commonly
used on smaller Qbus VAXen. The 780, 750, 730, MV2000, 3100s and
many others didn't use it or didn't even provide for it.
FYI: The grey wall provides the basic information and even examples for
doing
device drivers.
The best example was some russian chap that did a PIO interface (simple)
for a PDP-11 or Microvax (qbus). Even had drivers for both if memory is
working.
It was not the fastest way to go but cheap.
>experience, though not DEC's fault. It's too bad the PC folks didn't
think of a
>way to hook an external device to the PC internals without direct access
to the
>bus the way this board does things. That allows you to aviod the
"broken" I/O
>device from making the system "broken" as well. I still have the doc's
for that
>I/O board around somewhere.
ADAC and CSC to name a few make boards very similar to DRV11 some 8255
based, others Z80 PIO or TTL.. I've used several to hang custom IO on
PCs
without doing a bus interface.
Allison
I have several Lisa 2's and a pair of twiggy floppies plus a old Lisa
CPU board with
Lisa 1 ROM's on it. When boot system get 2 drive icon. Is it possible
to convert the Lisa 2's
back to Lisa 1 with this CPU board and the two twiggy drives?. Does
anybody have doc's for the twiggy drives. I am lucking enough to have a
new floppy for them.
thanks
