Der Floppy-Controller 1797 - Graf Elektronik FLO3 Handbuch

10.2 Der Floppy-Controller 1797
WESTERN DIGITAL
CORPORATiON
FD179X-02
Floppy Disk Formatter/Controller Family
FEATURES
• TWO VFO CONTROL SIGNALS - RG & VFOE
• SOFT SECTOR FORMAT COMPATIBILITY
• AUTOMATIC TRACK SEEK WITH VERIFICATION
• ACCOMMODATES SINGLE AND DOUBLE DENSITY
FORMATS
IBM 3740 Single Density {FM)
IBM System 34 Double Density (MFM)
Non IBM Format for Increased Capacity
• READ MODE
Single/Multiple Sector Read with AulomaticSearch or
Entire Track Read
Selectable.128,2SG, 512 or 1024 Byte Sector Lengths
• WRITEMODE
Single/Multiple Sector Write with Automatic Sector
Search
Entfre Track Write for Diskette FormaUIng
• SYSTEM COMPATIBILITY
Double Buffsring of Data 8 Bit Bi-Directional Bus for
Data, Control and Status
DMA or Programmed Data Transfers
All Inputs and Outputs are TTL Compatible
On-Chip Track and Sector Registers/Comprehensive
Status Information
PROGRAMMABLE CONTROLS
Selectable Track 1o Track Stepping Time
Side Select Compare
INTERFACES TOWD1691 DATA SEPARATOR
WINDOW EXTENSION
INCORPORATES ENCODING/DECODING AND
ADDRESS MARK CIRCUITRY
FD1792/4 IS SINGLE DENSITY ONLY
FD1795/7 HAS A SIDE SELECT OUTPUT
179X02 FAMILY CHARACTERISTICS
FEATURES
Single Density (FM)
Double Density (MFM)
True Data Bus
Inverted Data Bus
Write Precomp
Slde Selectlon Output
1791
X
X
X
X
1792
X
X
X
1793
X
X
X
X
1794
X
X
X
i
1785 ]1797
X I X
X j X
I X
X
X j X
X | X
APPLICATIONS
8" FLOPPY AND 5V*" MINI FLOPPY CONTROLLER
SINGLE OR DOUBLE DENSITY
CONTROLLER/FORMATTER
■: vcc"5V1
•1791(1= RG tT95)?=SSO
"1793/7 TRUE BUS
"17MHOPEN
PIN DESIGNATION
r
FCOPPY DISK
CONTROLLER
FORMATTER
FICLK
"hG'SSO
TROO
FD17BX SYSTEM BLOCK DIAGRAM
42