NAME

dl − DL-11 communications multiplexer

SYNOPSIS

DL0 at address 0x3ffd40/017776500 vector 0xc0/0300

DESCRIPTION

A dl-11 provides 4 serial communication lines.  Each line attached to the DL-11 communications multiplexer behaves as described in tty(4). Input and output for each line may independently be set to run at any of 16 speeds; see tty(4) for the encoding.

Bit i of flags may be specified for a dl to say that a line is not properly connected and that the line should be treated as hard-wired with carrier always present.  In the specification of dl0, indicating "flags 0x04" causes line tty02 to be treated in this way. 

FILES

/dev/ttyl[0-3]

SEE ALSO

tty(4)

DIAGNOSTICS

dl%d: overflow.  The character input buffer overflowed before it could be serviced.  This can happen if a hard error occurs when the CPU is running with elevated priority, as the system will then print a message on the console with interrupts disabled. 

4th Berkeley Distribution  —  1 August 1985