INTR (II)                    3/15/72                    INTR (II)

NAME            intr  --  set interrupt handling

SYNOPSIS        sys intr; arg  / intr = 27.

DESCRIPTION     When arg is 0, interrupts (ASCII DELETE) are ig-

                nored.  When arg is 1, interrupts cause their

                normal result, that is, force an exit.  When arg

                is a location within the program, control is

                transferred to that location when an interrupt


                After an interrupt is caught, it is possible to

                resume execution by means of an rti instruction;

                however, great care must be exercised, since all

                I/O is terminated abruptly upon an interrupt.  In

                particular, reads of the typewriter tend to re-

                turn with 0 characters read, thus simulating an

                end of file.

SEE ALSO        quit(II)


BUGS            --