INS1771-1
INS1771-1 is Floppy Disk Formatter/Controller manufactured by National Semiconductor.
Description
The INS1771-1 is a programmable floppy disk formatter/ controller chip contained in a standard 40'pin dual-in- line package. The chip. which is fabricated using N-channel silicon gate technology. interfaces a floppy disk drive directly to a puter interface bus. The I NS1771-1 provides soft sector formatting. which may be either IBM 3740 patible or a user-selected sector format.
The INS1771-1 is designed to operate on a multiplexed. TR I-STA TE® S-bit bidirectional bus with other busoriented devices. The c!1ip is programmed by the system software via the bus and all data. status information. and control words are transferred over the bus lines.
Features
- Soft Sector Format patibility
- Automatic Track Seek with Verification
- Provisions for Miniature Floppy Disk Interface
- Read Mode Capabil ities Single/Multiple Record Read with Automatic Sector Search or Entire Track Read Selectable 128-8yte or Variable Record Length
- Write Mode Capabilities Single/Multiple Record Write with Automatic Sector Search Entire Track Write for Diskette Initialization
- 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
- Double Buffering of Data
- TTL patible
- DMA or Programmed Data Transfers
- Reduces System ponent Count
- On-Chip CRC Generation and Checking
- Direct Plug-in Replacement for Western Digital FD1771-1
INS1771-1 General (System Configuration
PARAll El!
SERIAL DATA
INTERFACE fl OPPY DISK DRIVE
© 1978 National Se~iconductor Corp.
0-73
Absol U_ Maximum Ratings
,
" "'"
,
VOO with Respect to VB
- -
- . . . +20 V to -0.3 V
Max Voltage to Any Input with Respect to VBB ... +20V to -0.3 V
Operating Temperature-
- -
- . O°C to +70°C Storage Temperatu, re
- -
- - -550 C to +125°C
Note: Maximum ratings indicate limits' beyond which...
