There have been a few versions of the utility imd2raw.c floating around
that will take Dave Dunfield's ImageDisk-created images (i.e. an .IMD file)
and make a linear binary image devoid of any metadata. This is similar to
the function of Dave's IMDU.COM program's /b switch.
I've corrected a problem with the assumption that all imd2raw.c descendants
to date have made: sectors that have a skew (i.e. not 1-1 interleaved)
weren't linearized correctly. The skewed sectors need to be written out in
"sorted" order, which is not necessarily captured/physical order. This is
easily verified by comparing output from "IMDU /b" to earlier imd2raw
outputs on any .IMD that has a sector skew that isn't 1, 2, 3 [...].
It's up on github here:
https://github.com/RetroFloppy/imd2raw
Hey all,
I was trying to track down some kind of image/photo of "what IBM VM/370
looks like" (the operating system)
I tried looking also in the IBM manuals - I'm just not finding much. Some
kind of image of what maybe a remote login looked like, a task process
list, or maybe basic file/folder management commands, or how an editor or
programming worked on that system.
There is a bit of media with a VM/370 emulator, but I wasn't sure how
accurately representative it was of a kind of "look and feel" of that OS.
What I'd need is maybe photographs of teletype printouts? This was still
early 1970s. Which is understandable not much of that was probably kept
around.
Thanks, just digging around - like wasn't sure if VM/370 was still
six-character filename limited like earlier 60s era OS's, or whatever
characteristics it had in operating it.
-Steve
> Paul Koning <paulkoning(a)comcast.net> wrote:
> On the other hand, the even more obscure DECnet/8 was found a couple
> of years ago. Its main limitation ....
Besides being Phase-I, DECnet/8 is not a "complete" implementation. The
only application provided is a console to console talk program that can only
talk to other PDP-8 nodes. There's no FAL, CTERM/RTERM, NFT, NCP, or any of
the other things you might expect. I think DEC expected customers to write
their own RTS/8 and DECnet-8 applications.
Bob
So back in the 1990's the dream server for me was an Everex system
called the Step/MP. Cube shaped, EISA bus, could take multiple 386/33
CPU blades and ran SCO. But all I had was memories as there was very
little info on the Net.
Today I was going through a closet I haven't been able to access for 20
years and in the Computerworld 1992 25'th anniversary issue I found it:
A 2 page monster ad about the Step/MP. $13k, could have six 486/33 CPUs,
EISA/ISA bus, 64mb of memory stock with support for 4mb SIMMs. So it did
exist....
Question is did any of them make it out there? SCO was the obvious OS,
but given that it was a SMP system I wonder if there was an NT 4.0 HAL
out there like there was for the NCR 3550/4300 series of multiprocessor
systems. Anyone have one? Seen one in the wild?
I am curious. Everex/STEP was always the best quality system for a
server, right alongside Compaq. Sad they went out of business.
Chris
I asked this before a few years ago but didn't come to a firm conclusion. The two parts are shown in this picture: https://rjarratt.wordpress.com/wp-content/uploads/2023/12/img_20231221_1123…
They are from a VT100 Monitor board. There is no schematic for my version of the board, but a related schematic is on p58 of this schematic: https://bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Schematic_Feb82.…. They are labelled Q414 and CR406, but the Feb 82 revision uses a different board and those two parts are in TO-220 packages rather than TO-3 as here..
I have removed both of them and tested them with a DMM. Neither of them measure as two diodes, they do not measure open circuit in any direction, so either they are both faulty or they are not transistors (unlikely). I have found a spec for a 2SB411 at https://alltransistors.com/transistor.php?transistor=10279. This seems to be a germanium transistor. When I last asked about this I had a conversation with Tony Duell, who was very sceptical that these could be germanium transistors, so naturally I am very doubtful that they are 2SB411 transistors. However, in the schematic Q414 is shown as NPN, the 2SB411 is PNP and this seems to match the way the part is connected on my board (Collector to HORIZ GND). I am working on a reverse engineered schematic.
Can anyone tell me what these components are so I can find a datasheet for them? Better still a suggested replacement would be really helpful, especially if they are 2SB411s because they seem to be hard to find.
Thanks
Rob
Nice, Jay! Thank you
> On Feb 22, 2026, at 18:44, Jay Jaeger <cube1(a)charter.net> wrote:
>
> On 2/21/2026 9:27 AM, Jacob Ritorto via cctalk wrote:
>> Hiya.
>> Is DECnet for RT-11 still lost? If not, anyone got a link to it?
>> thx
>> jake
>
> I may have *SOME* of it. I have three RX50's and one RX02 that have some DECNet RT V2.1 files. They are NOT distribution disks, and the disks have hand-written labels, so they might not even contain what the handwritten label indicates - I have not checked them out under SimH.
>
> Anyway, I just put them in my "bitsavers contribution" area of my Google Drive, and they can be found on my Google Drive at:
>
> https://drive.google.com/drive/folders/1fiOScGSpvLiVQ0yyOg2yC5EpqRKiKWQ5?us…
>
> JRJ
Hello,
I'm an employee with the National radio astronomy observatory here in Socorro New Mexico.
As part of our NGVLA upgrades, we are seeking to get rid of old data tapes from the tape reel days of Computing. These contain things such as the boot loaders, OS, specific collection programs and antenna movement programs.
I personally would hate to see these just wind up in the literal dumpster and would like to see them sent out to a museum or an archiving body that can preserve them and keep them safe as a dynamic part of history.
If anyone is interested or knows someone who would be interested in the VLAs data tape library please let me know.
V/R
Danielle Werts
Front end engineer
VLA Socorro New Mexico
