Does anyone have a cross-refernece list for Xerox house-numbered ICs? The particular one I am looking for is 733W21L1 It's an 8 pin DIL package. Pins 1,5,8 are not used on the PCB. The others are the conventional op-amp pinout (2 = -ve input, 3 = +ve input, 4 = 0ve supply, 6 = output, 7 = +ve supply). I've replaced it with the obvious 741, and am getting rather better results than with the original (the output of which was stuck at 6V), but I'd like ot know if the original has any odd characteristics. -tony