Allegro.pas 5 alpha 1 can load PNG files out-of-the-box. Just add unit al5image to the USES clause and call "al5image.al_init_image_addon;" procedure after initialising Allegro. Of course, as you said, your Allegro intallation must include PNG support.
I should complete the documentation, then Allegro.pas 5 should became the TRUNK and Allegro.pas 4 will became "legacy".
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