Example

If IRAS90 is currently in its default mode (i.e no history is being produced by any application), then this can be changed by assigning a true value to an application's HISTORY parameter; eg if the next application which the user wishes to run is SETQUAL, then the command could be

  SETQUAL HISTORY=T

SETQUAL (and all subsequent applications) will then add history information to the output NDFs. The default behaviour can be re-instated at some later time by assigning a false value to a HISTORY parameter; eg

  QUALTOBAD HISTORY=F

Note, not all IRAS90 applications have HISTORY parameters, only those which modify existing NDFs or create new NDFs. For instance, SHOWQUAL does not make any alterations to any NDFs and so does not have a HISTORY parameter.