MCL82 data protocol documents?

[TK]

Hello – does anyone have a document describing the down-n-dirty parts of the MCL82 protocol?  I’m working on a microcontroller which will serve as a generic Beomaster hub for my HA system, and while I’m at it, I thought l’d give a little love to the two or three global fans of the slightly-orphaned BM5000, to make it more compatible with the DL86 protocol by having the microcontroller act as a protocol bridge between MCL82 and DL86. I got a used BM5000 as part of a larger purchase of stuff, and the only thing I’ve been able to get it to do message-wise is to send an 8-byte code over Datalink when I select standby.

The commonly referenced “Datalink 86” 10-pager is not inclusive of any MCL82 information, so perhaps there is another internal document or knowledge out there that outlines how it works in a bit more detail?

[cklit]

I found something from 1978 here: https://beomikro.wordpress.com/wp-content/uploads/2020/11/datalinkprotokol.pdf
It’s in danish 🤷‍♂️

Source: https://beomikro.wordpress.com/

[TK]

Excellent stuff!  I had forgotten about that site, with so much great archival data.  This is a proposal on the Datalink protocol to be used by a Beomaster 8000 to communicate with a Beocord 800X and a Beogram 800X. Looks like a 6-bit protocol with flanking low-bits. If this is how they implemented it, it would allow me to add an interface from DL80/DL86 with an 8000 series with minimal effort, without needing the special box that B&O sold for that purpose.  It would only be as capable as the supported commands, but its a start.  Lovely!

Still looking for info similar to this for MCL82, so if you find anything related to that, I’m happy to receive it.

[Madskp]

TK wrote:

it would allow me to add an interface from DL80/DL86 with an 8000 series with minimal effort, without needing the special box that B&O sold for that purpose

You will however need a IR transmitter to interface with the BM8000 as it does not have the data connections in the speaker plugs like the BM5000 and the MCL2 compatible systems. B&O had a device called MCL Beolab kit type 1006/1007 to interface between MCL82 and BM6000 and BM8000 with an IR transmitter.

TK wrote:

Still looking for info similar to this for MCL82, so if you find anything related to that, I’m happy to receive it.

I do not have any other information than what you can find in the user and installation manuals that are available in the products section of this site.

However I have a couple of MCL82 link room boxes and trancievers. If you could use one of them so you can analyze the signals from it to the BM5000 you can get it for the price of postage. send me a PM if you are interested.

One interesting application for  your findings could be a translator device for Beolink 1000 signals to control the BM5000. B&O made a code converter at one point that has been mentioned in a few older threads, but I guess it is very rare to find. It is mentioned in this old thread https://archivedforum2.beoworld.org/forums/t/714.aspx

Location: Denmark

[TK]

@Madskp Thanks much for your offer! There may be a specific version of the MCL82 box that I could use for engineering purposes, and it would be most helpful to have one.  I will return with a model number in short order – perhaps you have one available.

With reference to controlling the BM8000 without IR- as it turns out, it may be as simple as attaching a 7-Din Y-splitter to the BM8000 Tape output, and intercepting/inserting all the Datalink traffic that way. I’ve successfully managed to do this using the BM7000 architecture, which affords me near-complete knowledge of all the I/O between all the system components. Based on these proposal drawings posted by @cklit, I’d expect the same can be achieved with the 8000 series – I’m now “just another component on the Datalink bus with a 5V pullup”.  For the DL80/86 in the BM7000 at least- there appears to be no error checking of actual data content sent between components, so I am already able do things like turn components on and off, spoof the track count, and directly control the component function as if I was the BM itself. So far all the components are happy to oblige, with my rouge inputs being dutifully accepted as authentic commands and status messages. I’m imagining the BM8000 will allow for the same – worth investigating!

Your thoughts on the BM5000 are exactly what I have in mind for my science project.  The BM5000 uses DL80 protocols for it’s internal component architecture (from what I’ve tested), so that part works already with my current codebase.  Where I’m currently stuck is in finding the external command-set where I can control the BM5000 itself via the eensy-weensy teeny-tiny single DL I/O pin that connects it to a MCL network.  If the MCL82 command-set is rich enough, I’d be able to add the feature you describe, and even more. Given that I already monitor both internal DL80 busses, I can also properly intercept all component status messages, and emulate a DL86 interface for the BM5000, allowing for advanced integration with other B&O components.  (for the 3 people globally who may care to do do, LOL!)

It would also be straightforward to have a BM8000 control a CD7000, for example.  It’s just a matter of creating a macro which monitors for the BM8000 “Play” command, and injects the DL80 “Play” command on the DL. There’s a bit more to it than that, but that is the general idea.

[Madskp]

TK wrote:

@Madskp Thanks much for your offer! There may be a specific version of the MCL82 box that I could use for engineering purposes, and it would be most helpful to have one.  I will return with a model number in short order – perhaps you have one available.

Just let me know. I had another thread about some of them a little while ago if interesting https://forum.beoworld.org/forums/topic/pile-of-mcl-equipment/

TK wrote:

With reference to controlling the BM8000 without IR- as it turns out, it may be as simple as attaching a 7-Din Y-splitter to the BM8000 Tape output, and intercepting/inserting all the Datalink traffic that way

OK that’s interesting, and probably also makes for a more stable connection

TK wrote:

I can also properly intercept all component status messages, and emulate a DL86 interface for the BM5000, allowing for advanced integration with other B&O components.  (for the 3 people globally who may care to do do, LOL!)

Great that you acknowledge that from the beginning, and as long as you have fun tinkering with it just keep up the good work 🙂

 

Location: Denmark

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