This directory contains a test example for the DEV_SAP class category. It implements a class TTY_IO that is derived from ACE_DEV_IO and adds a control method with specific features for a serial line connection (e.g. /dev/ttya and /dev/ttyb on UNIX systems). The reader/reader executable initializes its device-special file (given as command-line parameter), reads characters from it (until it recognizes character 'q') and sends the characters read to stdout. The writer/writer executable also initializes its device-special file (given as command-line parameter), reads characters from stdin (until'q') and sends them to the device. To run the tests I connect /dev/ttya and /dev/ttyb (with a zero modem cable) and start the reader with "reader /dev/ttya" and the writer (in a different window) with "writer /dev/ttyb". Characters typed in the writer window should now appear as output in the reader window. Note that characters are buffered till EOL.