VSPD.net 

Network Virtual Serial Ports Driver is an advanced utility, the purpose of which is to emulate null-modem cable on computers located in a TCP/IP LAN or connected to the Internet by creating any number of pure virtual serial ports in your system.
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Amiga Explorer 

Connect an Amiga with one or more PCs, and access Amiga resources (including virtual floppy, hard disk and ROM image files) from the Windows desktop. Supports serial and TCP/IP connections.
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Flash Terminal 

With Flash Terminal you can chat and exchange files via modem (including v.90, ISDN, ADSL) simultaneously without Internet! You can exchange up to 255 files at once with unlimited transfer resuming.
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Serial Port Terminal 

Use Serial Port Terminal to connect to remote computer using null-modem, send or receive various types of data over serial line, redirect data into specified file, monitor data exchange between serial devices, troubleshoot modem settings and more.
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