Western_Digital_FD1771
Western Digital FD1771
Floppy disk controller
The FD1771, sometimes WD1771, is a floppy disk controller chip produced by Western Digital. It is the first in a line of floppy disk controllers that Western Digital produced. It uses single density FM encoding introduced in the IBM 3740. Later models in the series added support for MFM encoding and increasingly added onboard circuitry that formerly had to be implemented in external components. Originally packaged as 40-pin dual in-line package (DIP) format,[1][2] later models moved to a 28-pin format that further lowered implementation costs.