P9842AB chip data sheet or identification
The writing on the top says:
As user2943160 has already kindly mentioned in the comments, you were focussing on the wrong part of the numbers on the top. :-)
This is a CD4528BC Dual Monostable Multivibrator, made by Fairchild Semiconductor (that's the " f " symbol), probably in week 42 of 1998 (hence 9842).
The suffix N identifies the package type - in this case, standard plastic dual-in-line (PDIP):
Source - Fairchild datasheet
I can't find the Fairchild datasheet on their website, but the Fairchild datasheet is (currently) available on the Digikey website (link). Other CD4528 manufacturer's datasheets would also likely apply (more or less).