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monswctl(1M)

read and set the monitor switch, and switch the screen

Package: monsw46, added for amigaux.

monswctl - read and set the monitor switch, and switch the screen

monswctl [ -d dev ] get | status | set value | rtg [ command [ argument ... ] ] | native

monswctl talks to the monitor switch, monsw(7), through its device, /dev/monsw (or dev). Opening the device loads the monsw module when it is not loaded yet. get and status open it for reading, so any user can ask; set, rtg and native open it for writing, which the node's mode (0644, owner root) leaves to root.

prints the five fields the driver reports, one per line: config, the value in effect and its meaning; source, where it came from (none, seed, set, patched); state, native, rtg or none (not switched yet); holder, 1 when a program holds the switch on the card's picture; ncards, the card drivers registered.
prints the same in one line.
makes value the value in effect, unless one is patched into the kernel; root only. value is a sum of the bits of monsw(7), in decimal or as 0x hex; -1 unsets it, so that the card's own value applies again. A value with any other bit is refused here, before the kernel sees it. The boot step /etc/rc2.d/S20monsw uses this to put the value from /etc/display into the kernel at every boot.
switches the monitor to the card's picture, runs command and switches back when it ends, however it ends. Without a command it holds the card's picture until the end of its input or until it is killed. Its exit status is the command's.
switches the monitor back to the chipset's picture.

0 done; 1 the device or the kernel refused, with one line that says why; 2 a usage mistake, before the device is opened.

/dev/monsw
the device, character major 52, minor 0, mode 0644, owner root.
/etc/display
the monsw line, the value set at boot; see display(4).
/etc/monsw
the older file: one line, the value. The boot step reads it only when /etc/display has no monsw line, and the boot log says so.
/var/adm/rc.log
the boot log: one monsw: line for each boot.

monswctl status
monsw: value 34 (SEL low=RTG) from set; state native; holder no; 1 card
monswctl rtg sleep 10

monsw(7), display(4), display.d(4), xstart(1), rc.subr(1M)

31 October 2026 monsw