POSTIN

/bin/sh

update-alternatives --install /usr/bin/xsidplay xsidplay /usr/bin/xsidplay-libsidplay1 10
[ -e /usr/bin/xsidplay ] || update-alternatives --auto xsidplay

POSTUN

/bin/sh

[ "$1" = "0" ] || exit 0
update-alternatives --remove xsidplay /usr/bin/xsidplay-libsidplay1