Thanks, yes, on pg 127, Brown states that the controller MC34025P can be configured as either voltage mode or current mode, but Brown specifically states he is putting it into current mode.
On page 132, Brown gives the schematic…..he has a current sense transformer….the resistor at the output of this is fed to pin9, and also to pin 7 ……he also feeds in a slope comp ramp into pin 7, which he drives from the oscillator (and he buffers it with a PNP).
As such, Brown is indeed using it as a current mode controller with added slope