To make a Null Printer Cable for use with a PLIP connection, you need two 25-pin connectors (called DB-25) and some 11-conductor cable. The cable must be at most 15-meters long.
If you look at the connector, you should be able to read tiny numbers at the base of each pin, from 1 for the pin top left (if you hold the broader side up) to 25 for the pin bottom right. For the Null Printer cable, you have to connect the following pins of both connectors with each other:
D0 2 --- 15 ERROR D1 3 --- 13 SLCT D2 4 --- 12 PAPOUT D3 5 --- 10 ACK D4 6 --- 11 BUSY GROUND 25 --- 25 GROUND ERROR 15 --- 2 D0 SLCT 13 --- 3 D1 PAPOUT 12 --- 4 D2 ACK 10 --- 5 D3 BUSY 11 --- 6 D4All remaining pins remain unconnected. If the cable is shielded, the shield should be connected to the DB-25's metallic shell on one end only.