The preferred way of interfacing the NET software (and other packet radio programs) to the radio is via an SCC card. It is named after the Zilog Z8530 SCC chip that is central in the design. Each SCC chip provides two independent HDLC channels, that can operate fullduplex when an external divider is provided or when the MODEM provides the clocks.
One example of an SCC card is the PA0HZP OptoPcScc card. Its features are:
The board is supported in many packet radio programs, including:
Several MODEMs are available with the interface as specified by the OptoPcScc card, including:
The PA0HZP OptoPcScc cards are used in most nodes in the Dutch packet radio network. Most nodes consist of a 386 PC with 2 or 3 OptoPcScc cards, operating under MSDOS with the NET-PE1CHL software. There are a few Linux-based nodes as well.
More info about the OptoPcScc, including schematics and board population diagram in EPSON FX-80 printable format, is available from this file: sccprin5.lzh.
Some info about the 4800 bps HAPN modem technology is available here: 4k8mod10.lzh.
The schematics and info about the DUOMODEM are in this file: duomod31.lzh.
To unpack these .lzh files, use lha213.exe or another LHA or LHARC compatible archiver.