test-drb September 2020

test-drb@ccmp.vtda.org

118 participants
99 discussions

by shadoooo＠gmail.com

Hello, I have a question about 9 track tapes and block sizes. What I know is that tape is subdivided in files by means of marks, and each file is subdivided in blocks of equal size. Programs like tar use a specific block size to create files on tape. However files can have different block sizes like bootloader file, installation dumps and root file system copy on 2.11BSD. Now suppose you find and unknown tape you want to preserve: using dd you could easily 1:1 copy tape files to hard disk files using a SCSI drive and Linux. But: how you know which block size is on the tape? Thanks Andrea

4 years, 2 months

Pro 350 Print Set

by robert.jarratt＠ntlworld.com

Manx lists MP-01394-00 as the Field Maintenance Print Set for the DEC Professional 350. I can't find this online and I was wondering if anyone has a scan of it by any chance? Thanks Rob

4 years, 2 months

PSA to SparcBook 2 Users

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.

4 years, 2 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

4 years, 2 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

4 years, 2 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

4 years, 2 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

4 years, 2 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

4 years, 2 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

4 years, 2 months

paging Jerome Fine

by jwest＠ezwind.net

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

4 years, 2 months

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test-drb September 2020