Atari 810 User manual

JULY I.980
FSOlSO5i
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TABLE OF CONTENTS
SPECIFICATIONS
THEORY OF OPERATION
BLOCK DIAGP&m & SCHEMATICS
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9.
10.
FLOPPY QUICKCHECK
TROUBLESHOOTI’NG GUIDE
DISASSPMELY/REASSE:.!BLY
ADJUSTllESTS
PARTS LISTS
APPENDIX
INDEX
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TECIip!ICAL SPECIFICATIONS
Uses ANSI standard Sk inch diskettes in a
soft sectored format.
40 tracks at 48 TPI track.density.
Sinqle density (FM), single sided recording.
Over 905 bytes storage per diskette.
709 sectors of 128 bytes each.
Mininum data access time: 236 milliseconds.
Averaye data transfer rate: 6000 bits per second.
Automatic stand-by capability (built in
microprocessor).
Up to four Drives can.be daisy chained to a single
400/800 Computer Console (w/minimum 16K RAM)
via select switches at the rear of the Drive.
Drives directly interface with the ATARI 400/800
Computer Console (16K RAM) or indirectly through
the ATARI 850 Interface Module or 820 Printer.-
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THEORY OF OPERATION
The ATARI 400/800 Computer Console with 16K of RAM
installed connects directly to the 810 Floppy Disk
Drive.
The Drive may also be daisy chained through
the 820 Printer 6r the 850 Interface Module. up to
four Disk Drives can be connected to a single Console.
Refer to the Disk Drive Operators Manual for instal-
lation and oDerating instructions.
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The ATARI 810 Floppy Disk Drive consists of the
following major sections:
*Data Input/Output and Manipulation
*
Data Interface
* .Read/Write and Erase Heads
’ *
Stepper Motor and Logic
*
Diskette Drive Motor and Logic
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Power supply
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DATA INPUT/OUTPUT AND MANIPUWTION SECTION
Data, control commands and a VCC/RDY signal from the
Computer Console enter the Disk Drive through cithcr
of the two serial I/O connector jacks at the rear of,
the Drive chassis.
Each of the three main signal input lines are buffered
for,statlc protection an&to reduce power consumption
on the 800 I/O lines.
Data is sent by the Console in serial format, with
checksums accompanying the data for validity verification.
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The Drive’s PIA is primarily a buffering and signal
formatting device, with no decision making or compu-
tational capability. It is responsible for the
following:
*
Applying the Console’s serial outputs to the
Data 2nd Address Busses when requested by the
Drive’s Microprocessor Unit (NW).
*
Assisting in the control of the Read/Write
and Erase fiead position by buffering commands
sent to the Stepper Motor Logic.
*
Assisting in control of the Diskette Drive
,Motor Logic.
*
Providing 128 bytes of R&M for temporary
storage of status inforrnltion and data sent by
the Data Interface Section for application
to the HP".
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The MPU rjrovides the.primary decision making and
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cocputational capabilities for the Disk Drive.
The
Drive’s ?:PV is responsible for the following:
*
Controlling data transfers, through its
control over the Conmon Data and Address
Busses.
*
Intfr?retinq and controlling the accon,plishment
of Console commands (temporarily stored
in FLXM) and Disk Drive operating instructions
(permanently stored in ROM).
*
Controlling the Stepper, Disk Drive and llotor
Logics, which are buffered by the PIA.
The Drive’s ROM contains specific operating instructions
used by the CPU to accomplish a variety Qf-functions.
These functions include telling the Disk controller
(1771-01) what task to perform.
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The Drivs’s RXY is used by the CPU for temporary storage
of both data and system information.
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