22 Nov
2009
22 Nov
'09
5:46 a.m.
I managed to locate two nicely working RK05J drives (though the voice
coil/head assemblies were removed but I'm trying to get two more from
another guy but damn, those things apparently weigh 80 pounds alone! Think
of the shipping costs! D:) and now I'm really intent on finding either a
PDP-8 or PDP-11 Omnibus system I can run them with. I have been trying my
local Craigslist (as well as others but the listings kept on getting
flagged) but it's a ghost town and I got leads at a place called FreeGeek in
Vancouver but they have never seen a PDP come in through their doors, ever.
I'm running out of places to search and ideas on how to bring my searching
for a PDP to the attention of people who have systems they no longer need or
are willing to part with theirs. I saw alt.sys.pdp8 and alt.sys.pdp11 but
they are both rather empty so I don't know if a yell for help would be heard
there. Any help or offers would be appreciated very much.
Also, most of the bulbs on the front panels of the drives have burnt out.
Are these just regular 12v bulbs? I saw someone replaced the lights in their
drives with LEDs and that would be a bit nicer as LEDs would never have to
be replaced again.
Also, I received only the drives. I saw several flip chips in the thing and
a single empty slot. I'm assuming that the flip chips are the controller and
the empty slot contained a board which gave you a ribbon cable connection to
the omnibus backplane in the PDP or are the chips in the drives "fridge
logic" and I'm missing the controllers?
Thanks.
22 Nov
22 Nov
6:08 a.m.
On Nov 21, 2009, at 9:46 PM, John Ball wrote:
I managed to locate two nicely working RK05J drives
(though the voice
coil/head assemblies were removed but I'm trying to get two more from
another guy but damn, those things apparently weigh 80 pounds alone!
If the head/voice coil assemblies have been removed you'll have to go
through the entire alignment procedure which requires a special
alignment pack. You'll also want to make sure that all of the dreaded
"DEC foam" has been removed and replaced or you're heads and packs
won't last long. You'll also want to look at the filters and make
sure they're in good shape and replace them (if you can find them).
However, bad filters will also kill the heads and packs.
If the head/voice coil assemblies have been removed how do you know
that the drives are working?
Think
of the shipping costs! D:) and now I'm really intent on finding
either a
PDP-8 or PDP-11 Omnibus system I can run them with. I have been
trying my
local Craigslist (as well as others but the listings kept on getting
flagged) but it's a ghost town and I got leads at a place called
FreeGeek in
Vancouver but they have never seen a PDP come in through their
doors, ever.
I'm running out of places to search and ideas on how to bring my
searching
for a PDP to the attention of people who have systems they no longer
need or
are willing to part with theirs. I saw alt.sys.pdp8 and
alt.sys.pdp11 but
they are both rather empty so I don't know if a yell for help would
be heard
there. Any help or offers would be appreciated very much.
Also, most of the bulbs on the front panels of the drives have burnt
out.
Are these just regular 12v bulbs?
They're one of the standard DEC lamps. I don't recall off the top of
my head what the equivalent lamp # is but they (or a reasonable
facsimile) are readily available.
I saw someone replaced the lights in their
drives with LEDs and that would be a bit nicer as LEDs would never
have to
be replaced again.
Also, I received only the drives. I saw several flip chips in the
thing and
a single empty slot. I'm assuming that the flip chips are the
controller and
the empty slot contained a board which gave you a ribbon cable
connection to
the omnibus backplane in the PDP or are the chips in the drives
"fridge
logic" and I'm missing the controllers?
For an omnibus PDP-8 you need an RK-8E controller that goes in the
omnibus chassis. The "hard" part is finding the cable that goes from
the RK-8E and the drive. For a PDP-11 (unibus) you need an RK-11D
controller. It is actually a 4 board set in it's own backplane that
goes in the CPU chassis. There is also an RK-11C for unibus but that
controller is of the "old style" that has 40 or so flip chips in a
rack width backplane and is mounted outside of the CPU chassis in a
rack (requires a separate power supply) that connects to the CPU with
unibus cables.
If you're not looking for a "blinken" lights machine, you're best bet
would probably be an 11/34 system. I have several that are "spares"
but right now I'm swamped and haven't been able to spend any time on
classic computer stuff.
TTFN - Guy
5:16 p.m.
I managed to locate two nicely working RK05J drives (though the voice
coil/head assemblies were removed but I'm trying to get two more from
Err, how on earth do you know they work if there are no heads or linear
postiioner? Mind you, most other faults can be repaired. Another common
problem, at least in the UK, is breakdown of the insulation on the blower
motor. This can result in flames. THe motor is almost impossible to
rewind (OK, somebody will prove me wrong), but it's not too critical, so
you can normally find something that will replace it.
another guy but damn, those things apparently weigh 80
pounds alone!
Well, they're heavy, but I didn't think they were that heavy. Maybe 80Lbs
for the 2 postiioners.
Think
of the shipping costs! D:) and now I'm really intent on finding either a
PDP-8 or PDP-11 Omnibus system I can run them with. I have been trying =
You cna use RK05s with (at least)
PDP8 Omnibus machines (with an RK8E controller which is 3 quad boards and
top connectors. And a cable to the drives)
PDP11 Unibus machines (RK11-C (backplane of flip-chip cards or RK11-D (4
quad cards in a special system unit backplane) controllers)
PSP11 Q=bus machines (RKV11-D controller. This is a separate box with 4
quad cards in it and cables to a Q-bus slot and the drive. It's not easy
to find a complete one!0
Also, I received only the drives. I saw several flip
chips in the thing =
and
a single empty slot. I'm assuming that the flip chips are the controller =
No. The boards in the drive are handle the positioner control, talking to
the heads, etc The interface (which is on a pair of parallel dual slots
so you can daisy-chain the drives, you put a M930 terminator card in the
unused slot of the last drive) has 'raw' read and wrtie data lines, write
gate, drive select lines (either 3 bit inary or 1-of-4, an 8 it us to
select the cylinde to seek to, etc).
The controller is machine-specific (see above). The RK11-C is, IIRC, aout
100 flip-chip cards. The others are smaller in board count :-)
-tony
5515
days inactive
5515
days old
2 comments
3 participants
participants (3)
-
ard＠p850ug1.demon.co.uk -
ball.of.john＠gmail.com -
ggs＠shiresoft.com