test-drb

test-drb@ccmp.vtda.org

101090 discussions

by ian.finder＠gmail.com

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.

5 years, 5 months

[TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> 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

5 years, 5 months

Zuse Z4 - Oldest Surviving Computer in the World - Lost in the archives

by osi.superboard＠gmail.com

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

5 years, 5 months

[TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> 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

5 years, 5 months

Datasheet / Info for Motorola SC5330 IC?

by derschjo＠gmail.com

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

5 years, 5 months

[TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jnc＠mercury.lcs.mit.edu

> 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

5 years, 5 months

Thoughts on restricted distribution documents (Dec Professional 350)

by cz＠alembic.crystel.com

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

5 years, 5 months

[TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems

by jfoust＠threedee.com

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

5 years, 5 months

ISO: Motorola MDP-1000 info/software

by derschjo＠gmail.com

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

5 years, 5 months

paging Jerome Fine

by jwest＠ezwind.net

Anyone know if Jerome Fine is still around and/or a good email address?

5 years, 5 months

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