20 Jan
2002
20 Jan
'02
2:05 a.m.
hi there!
hi pete!
well it´s a BA11-S i suppose by now.
the panel and the pcb wich connects to the
two disks were literally "hanging"
when i got the box, it was a pdp-cabinet
and a second 19inch rack, containig old,
unused stuff and the tk50 and those 2 disks
there is a separate power supply for the
disks
now the tk50 and the disks are on a separate
table
If I were to be really picky, I'd
say you meant microPDP-11/23. 11/23-plus
would mean a BA11-S enclosure with
a different type of backplane :-)
mine is about 40 inch high, 19 inch wide and
as deep as
the rl02 is. the "microcomputer interfaces
1983-84" shows
some pictures of boxes: is might be the
BA11-S
The backplane itself has a
model number; for a BA23 it should
be H9728-A.
on the backplane i found H9276-A.
i don´t know what -A means, but it should be
a Q22/CD
so no serpentine?
I'm guessing you have a single
memory board, probably an MSV11-Q (M7551),
and an RLV12 (M8061, one quad
board) rather than an RLV11 (two
quad boards)
-- if not, that makes a difference
to the layout. I'm also guessing at a
DEQNA (M7504) rather than any
other Ethernet controller, but it makes no
difference to the placement, so
long as it's a dual-height board.
now i´ve got the numbers here:
CPU: M8190-AE KDJ11-B
MEM: M7551-CC MSVC11-QC
RL02: M8061
DELQA: M7516
RQDX3: M7555
DEQNA: M7546
There were some differences about whether
an FPU could be fitted (due to an
error on the original boards); those that
would not take an FPU were only
sold as KDJ11-BC and all had 15MHz clocks.
Others with 15MHz clocks were
sold as KDJ11-BB (upgradeable but FPU not
fitted). There are also some with
18MHz clocks, these were sold as
KDJ11-BE, -BF, or higher.
Normally an 11/83 has a KDJ11-BE or higher
suffix. Early 11/73 are 15MHz.
Just to add to the confusion, the -Bx
suffix actually refers to the
EPROMs on the board, not the clock speed or
the FPU. The *only* difference
between a normal KDJ11-BE or -BF or -BH is
the firmware in the EPROMs.
hmmm, this is really confusing, since i have
AE
can it take an FPU? maybe it has a fpu? what
does
the fpu look like?
However, the biggest difference
between 11/83 and 11/73 is whether the
memory is used as QBus memory, or
PMI memory, which is faster. All of the
KDJ11-B boards can use PMI memory.
Beware, not all quad memory boards are
PMI-capable, but all the 1MB and
bigger ones that I can think of are.
so i should put in first memory then cpu.
do all 11/83 use PMI ?
Yes. They will work with QBus
memory instead (and if you put a PMI board
after the processor instead of
before it, it will run as normal QBus
memory)
but then what you have is
effectively an 11/73, not an 11/83.
Literally "hanging"? Not fixed to
the front of the BA23? Is this actually
a floor-standing (or possibly
rack-mounting) BA23 with space for
a TK50 and
a drive unit, or a rackmount
BA11-S or BA11-N chassis with no space for
drives?
Neither have I. DEC used
pushbuttons for the disk controls
on microPDP-11
panels. Each section is separate,
though; it sounds like someone has
replaced the pushbuttons or used
third-party sub-panels. The round hole
(if this is an original DEC panel)
it´s a original dec panel and dec pcb.
is for the badge that says whether it's
a microPDP-11/23, microPDP-11/73,
microPDP-11/83, microPDP-11/53, etc. The
rectangular hole is for the power
switch in a BA23 or BA123 cabinet.
i suppose they changed CPU and memory from
the pdp11/23plus and put in half a 11/83.
the 3 switches at the frontbezel of the
BA11 work, the other "front"panel at the back
(from a 11/83) is only used to put the disks
online and write protect them. this would
also
explain why there is a connector "hanging"
at the rear-frontpanel.
a weird pdp.
--lothar