WD1772 dummy adapter

This simple adapter allows using Atari ST / STE computer without WD1772 chip. WD1772 controller is used to manage floppy drive in the 16-bit Atari computers and due to its rarity this adapter can be used to replace it. Obviously, when the original chip is not present, Atari is unable to communicate with floppy drive. The computer is also unable to start properly (throws two bombs) with the chip removed, as DMA chip can't establish if it should boot the system from the floppy disk. This adapter tricks DMA into thinking that floppy boot is not required and no request are coming from floppy interface.

There are few scenarios where this adapter can be helpful:

• Original WD1772 chip is faulty and you cannot obtain replacement
• You want to repurpose the WD1772 in a different computer
• You do not need a floppy drive in your Atari as you are using a hard drive or similar storage device

Idea and PCB project by Mq-workshop.