1983 Master Control Link System wiring guide

This topic has 3 replies, 4 voices, and was last updated 13 hours, 7 minutes ago by lausvi.

Viewing 4 posts - 1 through 4 (of 4 total)

Author

Posts
24 March 2026 at 02:19 #107230

pl212
SILVER Member

I’ve scanned and uploaded this document, which is contemporaneous with the Beocenter 7700:

https://archive.org/details/1983-bang-olufsen-master-control-link-system/

I find these early MCL systems fascinating, not because they were perfect (lots of issues about incomplete remote control) but because they were a fledgling attempt to get whole-house automation working over just a few extra pins in a speaker cable!

Location: Silicon Valley
My B&O Icons:

24 March 2026 at 05:01 #107856

TK
BRONZE Member

Thanks for the document, @pl212. You’ve probably seen the MCL’82 protocol document (attached) that I uploaded a few months back. It represents the final variant of MCL1 before the release of MCL2 (Datalink ’86). There was almost no documentation that I could find when I assembled this protocol document, which was created mostly by me spying on the messages being passed between a Beomaster 5000 and MCP 5000. There are still a few straggler messages whose meaning I have yet to fully decipher, which I hope to get to some day.

I recently acquired an original MCP, designed for use with the Beocenter 7700 (which I don’t yet have). Just based on the jumpers I see in the 2041 relay boxes, I’m thinking the MCP instruction set is unique to the 7700 – or at least the response messages will be – but I’d venture to guess there will be some overlap in the command set between the MCP and MCP 5000. Having just the MCP, I’ll be able to verify outbound commands for starters. If you happen to have a Beocenter 7700, perhaps you can add to the knowledge-base by providing the responses for the documentation.

I’m in Marin, so we’re close by each other, and can get together to compare notes over lunch, if you’re interested.

Attachments:
You must be logged in to view attached files.

24 March 2026 at 08:37 #108194
Madskp
GOLD Member
pl212 wrote:

I’ve scanned and uploaded this document, which is contemporaneous with the Beocenter 7700:

https://archive.org/details/1983-bang-olufsen-master-control-link-system/

I find these early MCL systems fascinating, not because they were perfect (lots of issues about incomplete remote control) but because they were a fledgling attempt to get whole-house automation working over just a few extra pins in a speaker cable!

Very interesting to see that this document also existed, and seems to be before it was rebranded to MCL82, but also only Beocenter 7700 is mentioned in the manual where later a fwew more systems were supported.

I have scanned the installation and user manual that came in the MCL82 packages, and there are available here at Beoworld in the products section under Beolink, but this manual seems to be more thorough about hidden installation types.

TK wrote:

Just based on the jumpers I see in the 2041 relay boxes, I’m thinking the MCP instruction set is unique to the 7700 –

Based on the boxes I have ( https://forum.beoworld.org/forums/topic/pile-of-mcl-equipment/ ) the jumper positions can be:
- Beocenter 7000/7002
- Beoceter 7007/7700 Link room
- Beocenter 7007/7700 Center room
- Beomaster 5000 / Other
So yes there seem to be some differences between systems, probably due to different remotes for the products

<pre id=”tw-target-text” class=”tw-data-text tw-text-large tw-ta” dir=”ltr” tabindex=”-1″ role=”text” data-placeholder=”Oversættelse” data-ved=”2ahUKEwiN6ZXljriTAxW_cfEDHUf4F0kQ3ewLegQIDBAW” aria-label=”Oversat tekst: thorough”>

<pre id=”tw-target-rmn” class=”tw-data-placeholder tw-text-small tw-ta” dir=”ltr” tabindex=”-1″ role=”text” data-placeholder=””>

Location: Denmark
24 March 2026 at 22:11 #110591
lausvi
SILVER Member
Thank you for scanning, MCL stuff is always appreciated!

I was looking at your other manuals and I hadn’t seen this use case mentioned before: in the MCL2 System manual:

I find the idea of a teenager having an MCL link system in their room amusing, and how B&O managed to turn a safety circuit into a parental control feature! Only preset volume parties for the teenagers! 😁
- This reply was modified 13 hours, 6 minutes ago by lausvi.
Location: Helsinki - Finland
My B&O Icons:
Author

Posts