=============================================================================== TITLE : LapLink cable specifications. DATE : 18-08-1994 AUTHOR : C. Holz. EMAIL : cholz@wilbur.mbark.swin.oz.au =============================================================================== Serial link cable. ------------------ Make a serial cable with two female DB25 (or female RS232) connectors. Seven connections are required. Wire the cable as follows: 9 pin 25 pin 25 pin 9 pin ===== ====== ====== ===== pin 2 pin 3 <---> pin 2 pin 3 (Receive-Transmit) pin 3 pin 2 <---> pin 3 pin 2 (Transmit-Receive) pin 4 pin 20 <---> pin 6 pin 6 (DTR---DSR) pin 5 pin 7 <---> pin 7 pin 5 (Grd---Grd) pin 6 pin 6 <---> pin 20 pin 4 (DSR---DTR) pin 7 pin 4 <---> pin 5 pin 8 (RTS---CTS) pin 8 pin 5 <---> pin 4 pin 7 (CTS---RTS) =============================================================================== Parallel link cable. -------------------- Make a parallel wiring box with male DB-25 connectors at both ends. Fifteen connections are required. 25 pin 25 pin ====== ====== pin 01 <----> pin 01 pin 02 < > pin 15 pin 03 < > pin 13 pin 04 < > pin 12 pin 05 < > pin 10 pin 06 < > pin 11 pin 10 < > pin 05 pin 11 < > pin 06 pin 12 < > pin 04 pin 13 < > pin 03 pin 14 <----> pin 14 pin 15 < > pin 02 pin 16 <----> pin 16 pin 17 <----> pin 17 pin 25 <----> pin 25 (Grd---Grd) =============================================================================== Null modem plugs. ----------------- The best way I have seen to make you own laplink cables is to purchase two DB25 wiring boxes. One Male to Male, the other Female to Female. The Male to Male is wired up as a Parallel null modem, and the Female to Female as the Serial null modem. All that is needed then is a standard serial EXTENSION cable (Male to Female DB25). By plugging the Serial Null modem into the Male end, you have a full serial laplink cable with Female to Female connectors. Or visa-versa by plugging the Parallel Null modem into the Female end, you have a full parallel laplink cable with Male to Male connectors. The only single problem with this is, that the serial null modem will not plug into a standard RS232 9 pin plug. This can be overcome by purchasing one or two convertors (9 pin Female to 25 pin male). =============================================================================== Laplink extension cable. ------------------------ Instead of forking out large amounts of money for an extension cable for your current cable or for the null modem, and extension cable can be made from the following specs. Make a cable with one female and one male DB-25 connector at either end. Fifteen wires are required. Four jumper wires are required between pins. 25 pin 25 pin ====== ====== pin 01 pin 01 pin 02 pin 02 pin 03 pin 03 pin 04 pin 04 pin 05 pin 05 pin 06 pin 06 pin 07 / 25 pin 07 / 25 pin 10 pin 10 pin 11 / 20 pin 11 / 20 pin 12 pin 12 pin 13 pin 13 pin 14 pin 14 pin 15 pin 15 pin 16 pin 16 pin 17 pin 17 =============================================================================== Information. ------------ These specifications are complete to my knowledge. The specs allow in laplink what is known as Accelerated Transfer, which is much faster than Standard transfer. These cable have been fully tested for DOOM. To play DOOM over parallel link, it is necessary to acquire a file called DOOMPAR.ZIP produced by an author called Andrew who produced a serial driver for use with DOOM r1.1. One warning with using the parallel connection with DOOM, that some computers do not work and a connection is never found. ===============================================================================