RE: Need for separate Input and Output Areas in Display File

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

ARGH!  Careful here.  I just got bitten by this particular issue.

> > WORKING-STORAGE SECTION.
> > 01  HEADER-OUTPUT.
> >     COPY DDS-HEADER-O   OF PAD0137NW.
> > 01  HEADER-INPUT.
> >     COPY DDS-HEADER-I   OF PAD0137NW.

This creates separate spaces in memory for each object.  There is no chance
for one to overlay the other.

>        01  DSPFILE-area.
>            copy dds-m1map-o     of OE314D.
>            copy dds-m2ctl-o     of OE314D.
>            copy dds-m2sfl-o     of OE314D.
>            copy dds-m2key-o     of OE314D.

With THIS technique, however, each record shares the same memory location.
Changes to dds-m1map-o", for example, are reflected in "dds-m2ctl-o".  If
you're lazy and don't update your variables prior to each WRITE operation,
you can get decimal data errors quite easily.

Joe