ALF built several cards and side expansion units for use with ST506/ST412 drives as well as adapting PC ISA cards for use with the Amiga. Unfortunately most of these units did not support auto-booting so in order to correct this, a card was released containing a GAL and some EPROMs to enable the card to autoboot. Please note however that the image doesn't show the card made by ALF, but probably a home-built version, as an unknown magazine did an article on making your own autobooting card.

Thanks to Pitteloud Stephane and Nils