Iskra Delta Triglav (Trident) computer [Slovenia/Yugoslavia] - MFM drives archived using this hardware

[Marko Štamcar]

    Hello, mr. Gesswein and group members,

I would like to thank you for your contributions to the MFM reader and its continued maintenance and support!

I am a volunteer at the Slovenian Computer History Museum.

One of our most treasured exhibits is the collection of computers and terminals made in Slovenia by Iskra Delta and companies related to it in the late Yugoslavian regime in the 80s.

Iskra Delta (fresh documentary available for rent here: https://vimeo.com/ondemand/iskrevcasu/637583904 - based on this book by the ex-director: https://www.amazon.com/Cold-War-Information-Technology-Inside-ebook/dp/B00C1NWL2E/ ) was mostly doing DEC/Digital distribution in Yugoslavia and its allies, but was not limited to just reselling, it also made its own designs of both hardware and software based on DEC.

The Triglav computer (also called Trident in english), named after our tallest mountain (which has 3 peaks) was one of Iskra Delta's top achievements - not only was it available in an iconic industrial design (see photos) that earned its designer a commemorative stamp ( see https://bratasevec.eu/ ), it was available in 3 different configurations, with DEC J11 CPU being the most common. See https://jurem.github.io/SloRaDe/en/computers/iskra-delta-triglav/ for more information in English.

We have 3 such machines in our collection (and a 4th Triglav with Motorola CPU), 2 of them in "plain" cases (photos labeled v2) and one in the celebrated design by mr. Brataševec (photos labeled v1). There remain just a few of these computers and we're happy to say that ours work.

The museum was not until now able to archive the hard drive contents (with DELTA-M OS, which is a rebranded and modified version of RSX-11M, but I'm happy to report that all 4 hard drives (all Fujitsu models - see photo) were without read errors and recognized immediately - I'm attaching the mfm_read logs. I bought the MFM reader/emulator and Beaglebone from DECromancer. The data in disk images required pairs of bytes to be swapped before legible.

I was not yet able to extract the files which are supposedly in the DECFILE11A/Files-11/ODS-1 file system format, despite multiple attempts using the tools Google finds on Russian sites - the main tool being ods1reader. The only thing that worked was an old DOS binary f11read.com which shows the directory listings but the tool does not support data extraction. If anyone is able to help with this, I will be very grateful!

The next thing to do now is to adapt the simh emulator or write a new one to actually boot the DELTA-M OS! We have a volunteer that has such skills and are hoping to work with him on this project. However if anyone has sufficient simh knowledge and is willing to help, please get in touch.

We have more computers and MFM drives to work on, but until then, regards to this community and keep up the good work!

Marko Štamcar

Vice president of the Slovenian Computer History Museum

https://www.racunalniski-muzej.si/about/

[Marko Štamcar]

(I was unable to attach all files in the first post.)

[Joan Touzet]

Hi Marko,

What an exciting project! I'd never heard of the Triglav from Iskra Delta before. I knew of the Elektronika PDP-11 clone, but not this one. Sounds like the Triglav was based on real DEC parts, though, not Soviet cloned chips? (Working with metric-spaced pin packages is tough these days.)

Your best bet for dumping the files out of your binary disk images would be PUTR.COM: http://www.dbit.com/putr/  This does run well in DosBox or DosBoxX. It should be able to access the image using its container file support -- best to give your image file a DOS 8.3 name with a .DSK extension before mounting its containing folder in DosBox.

PUTR is also available within the simh simtools archive, https://github.com/simh/simtools .

Failing that, another option is to bring your virtual disk into a PDP-11 SimH emulation, then run KERMIT-11 on that system to extract the file via a serial port. http://www.columbia.edu/kermit/pdp11.html has the software, with an explanation on how to get it into the machine. Kermit for Windows/Mac/UNIX/OS/2/etc is available on the same site.

There is also Joerg Hoppe's PDP11GUI tool, which performs the same "file-data-over-serial" trick but uses the PDP-11 ODT console for access. Since this includes SimH, you can use this without powering the Triglavs back up. More info is here: http://www.retrocmp.com/pdp-11/pdp11gui/disk-images-readwrite

Finally, the good folks at the ClassicCmp Discord's #medialab or #minicomputer channels may have more ideas. You can join via invite code https://discord.gg/KaczB5mz for the next 7 days.

Best of luck with your continuing efforts! I would love to see that image or content made publicly available, if possible. It'd be interesting to know what other modifications were necessary to RSX-M for DELTA-M, and more about the Motorola (68k?)-based machine.

All the best,
Joan Touzet @ Decromancer

[Marko Štamcar]

Hello Joan,

thanks for making the MFM reader/emulator + prepared Beaglebone so easily available - our museum being a volunteer society, there's so much to do

and I would not be able to build one myself at present time, but this way we were finally able to recover the hard drives that nobody has dumped before.

Yugoslavia was a distinct regime from the Soviet Union, much more open to the West and was able to get support from the US, so these were all real imported parts.

I was born in 1986, so I only learned in detail about Iskra Delta in the last few years, but even though we never had our own CPUs, there's much to be proud of for

a country of 2 million :) More at: https://jurem.github.io/SloRaDe/en/

I have also tried putr (forgot to mention) and while it recognizes the drive label, it lists no files/directories (compare to attached DELTAM21.TXT output from f11read.com).

It might of course be the case of me not knowing how to use this tool correctly or not knowing how to select the proper directory :)

(C:\)>mount t: tr.dsk /FILES11
(C:\)>t:
(T:[0,0])>dir
 Volume in drive T is DELTAM21
 Directory of T:[0,0]*.*
?Dir not found
(T:[0,0])>

I have also tried adding it as a second drive image in the SimH emulator but last time I tried it just gave me some I/O errors - will try again ASAP to report with actual logs.

Thanks for the Discord invite, I have joined the server and have started a discussion with our museum society if we have any concerns regarding giving you guys access

to a disk image - I don't think there is many reasons not to do it, so I'm feeling optimistic - will let you know :)

Extracting the files would be great, but if someone can help us boot it in SimH, that would be awesome!

A publicly available SimH emscripten page would make for a very interesting exhibit piece.

Thanks and keep up the good work!

Marko

[Marko Štamcar]

Hello all,

just a quick update in case it helps someone. We have now made progress - the data extraction issues we experienced are due to MFM reader code

incorrectly detecting that the drive only has 8 heads (FUJITSU M2243AS2 actually has 11), so we were only getting partial (corrupt) data from it.

Using a simple "./mfm_read --trans filename --cylinders 754 --heads 11 --drive 2" we were able to image the drive and are now working with mr. David

on fixing the data image extraction, too.

Using the transitions file we were also able to emulate the drive on a private collector's Triglav computer which was obtained without the hard drive.

All of this might be just trivia on a global scale but for Slovenian computer history it is priceless and we were lucky that by trying to emulate the drive

we noticed that the original MFM reader images were actually incomplete. Lesson learned - next time we will be sure to check the head count! :)

Kind regards to this wonderful community,

Marko

[Miha Grčar]

...and a "hello" from the private collector Marko is mentioning ;-)

It is pure joy to be able to boot up my Trident. I acquired it without a PSU, floppy, HDD, keyboard and several boards... and with a broken terminal. But where there is a will, there is a way. And the emulator played an important part in this journey. Thanks for this solid product and all the efforts that you have put into it!

This is the second Trident in the existence known to boot up :-D But I guess we will now be able to boot up several more of them.

Cheers,
Miha

[Forgotten Machines]

A True Forgotten Machine...this is wonderful!

Will you be making any YouTube videos of this machine, or publishing any images on any website(s)?

I'd love to see and learn more, thank you, and congratulations!

Best always,

AJ Palmgren

515.460.6393

http://MightyFrame.com

http://Entrex480.com

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[Marko Štamcar]

Yes, if Miha didn't need to emulate the drive because his was missing, we would not have discovered the true reason for why we couldn't decode all the data.

So to reiterate, what was needed was reading the HDD specs and reading the data off all 11 heads and the magic --head_3bit switch :)

At the museum we already did some videos last year - sorry that they are only in Slovenian language:

- Triglav/Trident boot up: https://youtu.be/pVR7JK6ffPA?t=1099 (go further back in video to see the outside of the machine)

- MFM reader demonstration: https://www.youtube.com/watch?v=5B6djKHgWjM

But I'm sure Miha will write a blog post about his adventures soon on his blog: https://www.oddbit-retro.org/ :D

Cheers,

Marko

[Forgotten Machines]

This is wonderful...thank you so much or sharing, and keep up the great work!!!

Best always,

AJ Palmgren

515.460.6393

http://MightyFrame.com

http://Entrex480.com

To view this discussion on the web visit https://groups.google.com/d/msgid/mfm-discuss/503a75dd-d486-4a46-aabf-3ae7bb2d1885n%40googlegroups.com.