Your increment example would show the interleave by looking at the subscripted global. Why not do this as:
S ^GLB=""
J1 ;
F I=1:1:100 S ^GLB=$G(^GLB)_"A"
Q
J2 ;
F I=1:1:100 S ^GLB=$G(^GLB)_"B"
Q
Wouldn't that show interleaving within standard M without using the explicit LOCK command. Obviously the actually control of the setting of the global would be controlled by the Global module of the the M system. In most systems today, 100 would not be sufficient to demonstrated your interleave. You might need something like F I=1:1:15000 Mostly likely J1 would run to completion before J2 even started. With most processes today, I doubt 15000 would be sufficient.
