PC/TCP Packet Driver

Packet drivers is a API for network cards under FreeDOS, DR-DOS, MS-DOS, etc.. made by FTP Software. It used the x86 interrupt number between 0x60 .. 0x80. The exact number is detected at runttime. But usually it's 0x60. An application scan through the handlers for vectors 0x60 through 0x80 until it finds one with the text string "PKT DRVR" in the 12 bytes immediately following the entry point. The driver can handle Ethernet, Token ring, RS-232, Arcnet, X.25.