Graphical BP7 app running in background on Win9x

  Do someone knows how to setup the Win98 to allow a Borland Pascal 7
application to run in background or in a normal window WHEN in graphics
mode ?

  Every time I'm running it in graphics mode and I hit Alt-Enter (to
change it from full screen to normal window) or Alt-Esc (to run it
minimized) the software stops execution. This application pools a serial
line performing aquisition on lots of PLC's, so, it cannot stop polling
when the operator changes to other Win app.

  The interesting is that that same app running text mode screens runs
perfecly in backgroung when minimized or a normal window.

Any suggestion?

Thanks
Ricardo Dunna