AIPS HELP file for GROFF in 31DEC19
As of Sun Aug 18 21:26:10 2019
GROFF: Verb to turn off graphic channel(s).
GRCHAN 1.0 8.0 Graphics channel
The desired channels may be given instead as an
immediate argument in BINARY code to GROFF. Example:
GROFF(13) will turn off Graphics channels 1, 3, and 4.
If there is no immediate argument and GRCHAN is zero,
all Graphics channels are turned off.
Use: Turn off (disable) one or more specified TV graphics channels.
Does not affect status either on or off of channels not
Note that, if GROFF is used in a FOR or WHILE loop or in an
IF-THEN-ELSE construct, then the immediate argument is required.
Otherwise, some item necessary to the loop/construct will be
taken as the immediate argument.
Adverbs: GROFF takes an immediate argument specifying in BINARY code
which channels to turn off. E.g. GROFF(43) disables graphics
channels 1, 2, 4, and 6 (values 1 + 2 + 8 + 32 = 43).
GRCHAN......Graphic channel. Only used if immediate argument is
omitted. If the resulting channel number is zero, then
all Graphics channels are disabled. Thus GROFF(0) and
GROFF(255) are equivalent.