Hi, Les
I only have one port hear, maybe this will help.
Mach3 port 1 is set to 0x387 as default.
Go to win Start bottom left click on it, click on Control Panel, then System, Select Hardware, then Device Manager, click on + next to Ports (COM & LPT), then DBL click on ECP Printer Port( LPT1), then Resources.
I think the first address on the blue IO is your Lpt 1 port address, Enter that address in Mach3 Config, Ports & Pins, Port #1, Port Address window.
Hope this Gets It, Chip