MMS Maintenance Handbook drawings

Modular Memory System with 80, 120, 240, 360, 480 channels. 
MMS was the first mass produced memory control and jumped two hurdles in a single stride: it took full advantage of low-priced integrated circuit technology, and dispensed fader or switch per channel in favour of a calculator style keypad and wheel, to control up to 480 channels.
The system consisted of self-contained function modules (which could be chosen by the purchaser) linked by a common signal bus, used singly or in multiples for facilties required. 
Channel control was by a dedicated numerical keyboard including (the now common) THRU, @ and the first use of a digital fader wheel. The Mimic module gave above-zero indication for each multiple of 120 channels. It used Ferrite Core memory.
First used in 1973 at the Birmingham Hippodrome, and the last was in 1979.
A total of 208 MMS desks were sold.