How do I connect two computers using a null modem cable?
You need a term program and RS 232 ports on both computers. The RS 232 ports need to be connected together using a ‘null modem cable’. For up to 4800 baud, no flow control lines need be connected. Just cross the transmit and receive lines and join the grounds together. Transmit is pin #2, receive is pin #3 and ground is pin #7 on the 25 pin port. 25 pin #2 goes to Atari #4 (XMT to RCV), 25 pin #3 goes to #3 on Atari (RCV to XMT) and #5 of 850 goes to #7 of 25 pin (GND to GND). The right hand pin on the ‘long’ side of a female ‘D’ connector is #1. There are 13 holes on this ‘long’ side, 12 holes on the ‘short’ side. The numbers go to the left 1 to 13 then #14 is under #1 and left again so that #25 is under #13. Most term programs allow a null connection, without a carrier detect. Notably, ‘850 Express!’ does not. I have only used ‘Procomm 2.4.3’ (the last shareware version of Procomm) on the PC and BobTerm on the Atari, but other term programs may work. To check your null modem connecti
