Justin
The "M" in these older schematics has the same meaning as "K" is later drawings. When using the letter "M" a schematic will spell out "Meg" is they want the larger value. This may have started from Roman Numerals where "M" meant 1000.
Norm
: The current schematic I'm reading has resistor values in "M ohms" , many of the values like "390 M ohms" seem huge. Curious to know if there is a source for such large values, or whether they're indicating something else (like K ohm) and I'm misunderstanding the old terminology.
: Justin