FEATURES
• SOFT SECTOR FORMAT COMPATIBILITY
• AUTOMATIC TRACK SEEK WITH VERIFICATION
• READ MODE
Single/Multiple Sector Write with Automatic
Sector Search or Entire Track Read
Selectable 128 Byte or Variable Length Sector
• WRITE MODE
Single/Multiple Sector Write with Automatic
Sector Search
Entire Track Write for Diskette Formatting
• PROGRAMMABLE CONTROLS
Selectable Track-to-Track Stepping Time
Selectable Head Settling and Head Engage
Times
Selectable Three Phase or Step and Direction
and Head Positioning Motor Controls
R
GENERAL DESCRIPTION
The FD1771 is a MOS/LSI device that performs the
functions of a Floppy Disk Controller/Formatter.
The device is designed to be included in the disk
drive electronics, and contains a flexible interface
• SYSTEM COMPATIBILITY i
Double Buffering of Data a-Bit Bi-Directional ....
Bus for Data. Control and Status
DMA or Programmed Data Transfers
All Inputs and Outputs are TTL Compatible

APPLICATIONS
• FLOPPY DISK DRIVE INTERFACE
• SINGLE OR MULTIPLE DRIVE
CONTROLLER/FORMATTER
• NEW MINI-FLOPPY CONTROLLER

GENERAL DESCRIPTION
The FD1771 is a MOS/LSI device that performs the
functions of a Floppy Disk Controller/Formatter.
The device is designed to be included in the disk
drive electronics, and contains a flexible interface
organization that accommodates the interface signals from most drive manufacturers. The FD1771 is
compatible with the IBM 3740 data entry system
format.
The processor interface consists of an 8-bit bidirectional bus for data, status, and control word
transfers. The FD1771 is set up to operate on a multiplexed bus with other bus-oriented devices.
The FD1771 is fabricated in N-channel Silicon Gate
MaS technology and is TTL compatible on all inputs
and outputs. The A and B suffixes are for ceramic
and plastic packages, respectively.