The Moog Memorymoog was a keyboard used by Dr Fink on the Purple Rain and Parade tours. Prince did not use a Memorymoog in the studio - it was one of several keyboards Dr Fink used to bring a different sound live compared to the studio recordings. It was hooked up to a Linn LM-1 for the sequenced bass part to I Would Die 4 U.
The only song that ever had any sequencing during the twelve years I performed with Prince was "I would Die For You." I used to lock the sequencer on my MemoryMoog synth to do the bass part with Bobby Z.'s Linn LM-1 Drum machine which had been modified to receive MIDI.