V1/man/man2/intr.2
11/3/71 SYS INTR (II)
NAME intr -- set interrupt handling
SYNOPSIS sys intr; arg / intr = 27.
DESCRIPTION When arg is 0, interrupts (ASCII DELETE) are ignored. 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
occurs.
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 return with 0 characters read, thus
simulating an end of file.
FILES
SEE ALSO quit
DIAGNOSTICS
BUGS It should be easier to resume after an interrupt, but I
don't know how to make it work.
OWNER ken, dmr