either:
a VC lag that can be made to hold-state on command. also can be put into cycle mode as well, giving a wide-range VC linear triangle LFO that ranges from around 700 Hz to 30 seconds or so per cycle. with external CV this range is extended from around 1500Hz to ???

and/or:
a sample and hold with controllable input slew [or sample 'correlation' ] the control input is the same.['s/h' in the drawing]. The 'droop' in either mode is extremely low- less than 500uV/S.

when cycle is selected in Hold mode, the section will generate complex staircase waveforms that are synced to input pulses.. [BTW the input signal doesn't have to be a pulse, but just about any rising slope, this was done to allow for even more inter-compatibility between the 2 sections.]

finally, the unlabeled jack in the middle is a gate output that compares the top section's output with the bottom.