This allows SBX subroutines to mimic a common behavior in traditional subroutines which do not do their own handling of Ctrl+C. The trick is to add the following to the error trap routine of the SBX module:

TRAP:

if err(0)=1 then

xcall ASFLAG,128      ! set ^C in parent

END                   ! exit SBX

Endif

If the flag argument is supplied as a 2 byte binary variable, then the previous flags settings will be returned in the variable, after the new settings are updated from the variable. This technique would be important when using ASFLAG.SBR to change the settings for just one file, returning to the original settings thereafter.