Serial Port for Diagnostic SW with MBE ECU ?

[crypto]

Trying to get the (old) diagnostic software running on my pc. What is the required com-port number and settings to get it running ? Are the general PC requirements ? WinXP ? USB-to-Serial-Port converter or physical Com Port ?

[crypto]

Hi folks, thanks for all the feedback ! I'll try this evening with 2 cables I already have and on COM1 (only).
Some more questions :
1) will the ECU only respond while ignition is on or also when off ?
2) can I use a (standard) 9 pin cable or do I really have to modify it according the wireing diagram picture (with the resistors) ?
3) coming out of the ECU there are 4 pins (on the big black connector) to control a stepper motor, what are they used for ?

Peter