Dwell control vs timing control

[Bruce Plecan]

gm specific
I been thinking way to much on this, but, I'll stick my head out again, and
say
what your reading in the prom is timing corrections, and the stuff for being
a cylinder late in the computations.
  If the dwell controll, was in the prom, then disconnecting the distributor
from
the ecm would stop the engine from running.  So the dwell control is in the
module.
  So every thing in the prom would look the same from Dissy to DIS.  Just
a matter of when the timing starts, as set by est signal.
Thoughts anyone?.
Bruce