zedstarr

Never one to miss an opportunity to revive an old thread... Another ROM found in the wild and imaged: https://github.com/andydoswell/Elektor-976516-1 md5sums the same so yay/meh but at least it's on the internet somewhere else 😉

I must have something set somewhere (default?) I heard a beep and saw a notification "kgallen mentioned you in a thread" ;-) And yes, this tab has survived in my browser since Feb! More importantly perhaps can I add my apologies for contributing to hijackingness ;-)

Noticed, but kept shtum :-)

Nice. PAT tested too :-D

@kgallen Seeing as the EEVBlog forum post on this same topic was the first one I came across (and the first one the OP posted to?) do you mind if I share the source code over there? I've zipped the C/Tcl/Python together

Disclaimer: I'm not a software engineer... Requires python3 - I'm sure there's a more elegant way that will support both python2 and python3 but it's late and I'm tired. I'll look again tomorrow after some sleep and a chat with an actual software engineer :-D (also there's a kludgy hack to define a fprintf function in python so I could get around converting the formatting of the ASCII hex output :-) ) Tested OK on Fedora 33, RaspiOS (buster) & MacOS Catalina. execute as: python3 elektor_scms_rom.py Enjoy! @kgallen I've just spotted an error in a comment in your original code which I've propagated through to the python: your line 72 "0x00 to 0x07" should be "0x00 to 0x06". Obviously doesnt affect the output files at all elektor_scms_rom.py

That is truly an epic piece of work Kevin! Many many thanks for the insight :-)

This is the most fun I've had in a long time :-D Isn't that often the way? Out of lockdown boredom I retrieved my MiniDisc kit out of the cellar and look where we are now :-)

Aye I was thinking about that last night :-) "Frame alignment words in timeslot 0"... The 2048kb/s interface (well the G.703 & G.704 realisations) are still in use in most (if not all) telecom networks today as synchronisation signals. Even big Cisco etc. switches that support Synchronous Ethernet and PTP (IEEE1588-2008) still have "sync out"/"sync in" interfaces that can handle the old PDH "2 Meg" signals :-)

As I read the file in Linux (on the Raspberry Pi) there's hexdump and xxd - tools that can format & decode the binary into ASCII hex. (both seem to be present on MacOS too tho you'll need to open the terminal to use these command-line utilities.)

SPDIF format - we're looking at the physical layer line code, not the actual audio data itself hence the "bi-phase" bit references below.

I did indeed, it's compulsory isn't it? :-D

Snippet: 0x717 & 0x81D locations of note 000006e0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000006f0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000700 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000710 0e 0f 0e 0f 0e 0f 0e 11 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000720 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000730 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000740 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000750 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000760 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000770 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000780 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000790 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000007a0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000007b0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000007c0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000007d0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 000007e0 0e 0f 0e 0f 0e 0f 0e 0f 10 0f 0e 0f 0e 0f 0e 0f |................| 000007f0 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f 0e 0f |................| 00000800 10 11 10 11 10 11 10 11 10 11 10 11 10 11 10 11 |................| 00000810 10 11 10 11 10 11 10 11 10 11 10 11 10 13 10 11 |................| 00000820 10 11 10 11 10 11 10 11 10 11 10 11 10 11 10 11 |................| 00000830 10 11 10 11 10 11 10 11 10 11 10 11 10 11 10 11 |................| Also - complete binary attached :-) I wanted to exhaust some of the other avenues of looking for the original author etc. before dumping the contents anywhere. Gratefully received. I have Happy Memories of riding the paternoster lifts in the Beeston Engineering block :-D elektor_scms_rom.bin.zip

For completeness here's an update on what I've managed to find out about the original article/author: First published in most European language versions of Elektor 12/1997, English language version 07-08/1998 Author: Dipl.-Ing. Hans-Juergen Hanft (not credited with any other projects on Elektor) no contact details found Georg Stippler - Stippler Elektronik, Bissingen Germany (suppliers of the kit/components) no contact details found At the time the Magazine Editor was Len Seymour - has his name on some books of collections of projects that were published like "305 circuits" etc. but not much else At the time the Technical Editor was Jan Buiting - he's now the Editor, still very active at Elektor and contactable on LinkedIn or via email. I reached out to him and his reply was: So, I have registered a trial membership on Elektor's "Labs Website" and have asked there also....

I've discovered the original article can be found in the Jul-Aug 1998 issue of Elektor held in the archives of https://worldradiohistory.com/Elektor.htm There's some detailed description of the pattern matching and/or ROM contents in there.

Seeing as "Stippler Elektronik" the original suppliers are no more and the original Pascal source was never published I don't see why not, for "educational" purposes. Are you planning on building a copy?

Coincidentally I've just retrieved my Elektor SCMS "copybit killer" from storage and had a play with it :) The pots to light the correct sample-rate LEDs needed a tweak but it still works fine. I'd also retrieved some of my "old" HiFi gear from storage too, including the MDS-JB930 minidisc deck! And my old Technics RS-B665 tape deck which I've since built a wireless remote control for, but that's another story :-) I bought the Elektor kit in Jan 2000 (I faxed the order over to Germany, how quaint :-D ) and used it a lot at the time for MD-MD copies. According to the invoice it cost me £48.38 I've imaged the ROM (and already discussed at length with the OP over on another forum!) initially using a Raspberry Pi (without level shifting) but I was worried about data integrity as the 27C512 is an old 5V part and the Pi GPIO is all 3V3 and not 5V tolerant. So I splashed out on a TL866 USB programmer and double checked. The original image good was after all. Reading the old 5V part at 3V3 at slow speed (1ms between reads) worked for me. Fascinating insight into the design of the SCMS stripper - in my career the last time I came across a (very badly designed) ROM state machine was in some Telecom kit (actually deep inside a System X telephone exchange in 1994 8-) )