This professional serial communication library DLL for Windows and DOS libraries supports ZModem, YModem, and XModem file transfer protocols, Hayes compatible modems, Microsoft Visual C/C++, Borland C/C++, Access, Visual Basic, Professional Basic, QuickBasic, and all tools that can call DLLs. It supports any number of ports running concurrently and any device that has a Windows serial communication driver (multiport card, USB, serial hubs, modems, PCMCIA, RS232, RS485, RS422).