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.