There is a 1000uf 10v cap on the main logic board just above the Bt display controller.
It is leaking... a lot. (4/4 samples so far)
Go replace it, flush the area and scrub the with 99.9% IPA.
> From: Liam Proven
> for my continuing education: what's a "Mini-Unix binary"?
Two possible meanings; a system image for a Mini-Unix system (buildable under
V6 with the standard V6 tool-chain of C-compiler/assembler/linker), and user
command binaries (buildable with the C-compiler/assembler, but needing a
special Mini-Unix linker - written in C, and compilable/runnable under V6).
I've done both in my recent Mini-Unix work.
(For those are are not familiar with Mini-Unix and LSX, they are both V6 Unix
variants lobotomized to run on PDP-11's without memory management: -11/05's,
etc. I'm currently working on getting Mini-Unix to run on an -11/03; not a
major change, but not a model supported 'out of the box'. LSX is more heavily
cut down, so it will run on even smaller systems - I seem to recollect 20KB
or so - but that's not that useful nowadays, with semi-conductor memory being
fairly common.)
Noel
A few days ago, it was published on BLOC at CACM that a lost user manual
for the Z4 and notes on flutter calculations was found in the ETH Z?rich
archives. See:
https://cacm.acm.org/blogs/blog-cacm/247521-discovery-user-manual-of-the-ol…
Zuse Z4, a relay computer of 1945,? however, due to lack of
documentation, its functionality was largely unknown. Now a manual for
the machine has appeared at ETH Zurich, that was buried in the archives.
And this in the digital age ...
Thomas
> From: Liam Proven
> Would the x86-32 "reimplementation" of v6 UNIX be able to mount and/or
> read-write such filesystems?
No, it looks like it uses a different fie-system layout.
Besides; there's not much point: the big adantage of using V6 is that one can
use the V6 tool-chain to prepare Mini-Unix binaries; XV6 wouldn't allow
that. If all one wants to do is get files in or out, there's already a program
(compilable with gcc, that uses Standard I/O) to read files out of a V6
filesystem. If there was any good need, it could be extended to write
(although that would be non-trivial).
Noel
I'm in the middle of working out the pinout for the power supply connector
on the MDP-1000. I'm aided somewhat by a set of test points on the
backplane, unfortunately the "+" and "-" symbols (in the solder mask labels
next to the test points) are nearly indiscernible, so I'm trying to verify
that I'm not mixing up + and - 15V.
On the core memory boards are eight Motorola SC5330 IC's (datecodes from
early 1969), which have pins connected to both the + and - 15V lines -- if
I can find a datasheet I could pretty easily confirm which is which.
Trouble is I can't find anything on this chip. I've scanned through the
databooks on Bitsavers, no luck. Anyone have any ideas?
Here's a picture in case that helps at all:
https://1drv.ms/u/s!Aqb36sqnCIfMpIVXm5draSrWHGMzJg
- Josh
> From: Warner Losh
> If we can't use MINIUNIX to rebuild MINIUNIX kernel, should we try to
> bodge together rebuilding via apout?
Good basic idea (using a different system to build on), but there's a
better/easier approach (in the same basic vein): bring up V6, and mount the RK
pack with Mini-Unix on it (it's a V6 file system, so is mountable); V6 is rock
solid running under simulators.
The V6 tools can I'm pretty sure be used directly to build new Mini-Unix
kernels; user program can I think use the V6 C compiler, but I'm pretty sure
not the standard V6 linker (the Mini-Unix linker loads tham at the
non-standard address used by Mini-Unix).
Noel
Question for the group: I have a document set here from DEC that is the
"XT Hardware Handbook". It's basically the entire pre-release
documentation set for the "XT-100" terminal/computer which became the
Professional 325/350.
Is there a copy of this on the internet, and what are the thoughts on
scanning this? Is there already a better copy of this information out
there, this seems to cover the whole internal bus, how the cards work,
and so forth...
Chris
At 01:51 PM 9/30/2020, Noel Chiappa wrote:
>I guess all this PDP-11 hardware detail isn't really on-topic for this list; I
>should move it to Classic Computers, or something.
I've got Riordan's udis[01..10].DSK disk images that I presume
are similar to http://www.bitsavers.org/bits/Terak/mini-unix/
IMD images.
Which filesystem would I find in these images, and which tool
can burst the image into its files?
- John
Hi all --
This is a long shot, but I was curious if anyone might have information on
the Motorola MDP-1000 minicomputer. I picked one up recently and I'm
working on restoring it. Of particular interest is the power supply, which
is external to the processor and which I am missing. I think I have the
voltages worked out (+/-5V and +/-15V), but there are a number of other
signals on the power supply connector that I'm unsure of at the moment.
I've put a few pictures up here:
https://1drv.ms/u/s!Aqb36sqnCIfMpIVYmzKjFnsT3nHh8w?e=b2iqqv
I'll note that this isn't technically an MDP-1000 -- it's labeled as an
MDP-6650 on the rear. I suspect that this is a ruggedized version of the
1000 intended for harsher environments. The front panel of mine appears to
be identical to the drawings of the MDP-1000 in the manuals I have.
It also came with a binder of documentation (but alas no schematics) that
I'll be scanning soon and getting off to Al. It's an odd little system --
5 12-bit registers, a 12-bit ALU, and a 12-bit Instruction Register, but
the memory is 8 bits wide. Instructions are packed into two bytes
normally, but there's a special 64-byte region of memory that can be used
to store "shared bytes," which allow encoding certain instructions into a
single byte, taking the other byte from the shared region. I've never seen
anything quite like this. I wonder why they didn't just use 12-bit wide
memory...
Also the process for using the front panel to examine and deposit memory is
insane. Here's the instructions for reading a memory location; it's 10
steps. Depositing is 17.
https://1drv.ms/u/s!Aqb36sqnCIfMpIVWThgwlxgCMQo59A
If anyone has anything on this, let me know. Not expecting much, but it's
worth a shot.
- Josh