The
scc driver provides support for the Zilog 8530 Serial Communications Controller (SCC) via the IOASIC found on DECstation 5000 models in the /100, /20, and /240 series (supported by
NetBSD/pmax).
Each SCC device has two serial ports. The DECstation 5000 model 20 provides one SCC device. Other models provide two, but one port of each device is dedicated to mouse and keyboard input, respectively.
Input and output for each line may set to one of following baud rates: 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, or 57600.
Speeds up to 230400 are supported by the chip and the motherboard, but speeds higher than 57600 do not work reliably without an external clock signal.