Just a quick list of the very few parts.

R1-11   100K Just to add input impedance and protect the chip
R12     15K
C1      10uF
C2      0.1uF
D1-2    1N4148 these are just small signal cheap diodes.
IC1     MC145050P from Motorola or try the TLC1543 from TI but I'd check out it's data sheet if I were you.
IC2     REF25Z any 2.5 reference will do.
CON1    25 Way D Male Solder bucket for the Printer port connection
CON2    25 Way D Female Solder bucket for the other end.

        I suggest you make the 25 Way Ds different 
        so you can't plug it in the wrong way around.


SMG'94