Diskette Adapter Card - IBM 6360 Product Support Manual

DISKETTE ADAPTER CARD
The diskette adapter card controls the
flow of data to and from the diskette
unit.' It accepts signals and control
commands from the system card and uses
them to supply all logic and signals
required to operate the diskette
drive.
The adapter card is an interface
between the system card and the
diskette drives and supplies the fol-
lowing circuits:
• Basic Assurance Test (BAT). The
diskette adapter microprocessor
controls the flow and timing of
data under the control of the sys-
tem card. The adapter tests
itself following each power on
reset.
•
•
•
This test is in two sections.
First the cable from the system
card to the adapter card is
checked. Then the read function
on the diskette adpater card is
tested.
Drive
Status.
This
status
includes fault, write protect,
ready, track 0, two side, and head
address data.
Track
Position.
The
adapter
stores
the track position in the
track position counter.
Diskette Drive Selection. The
adapter controls the selection of
the diskette unit.
This selection
depends upon the input of the
application program diskette. The
application program will select
the proper diskette drive if a
dual diskette drive unit is pres-
ent.
•
•
•
•
•
•
•
Track Step Timing. Clockcircuits
on the adapter card control the
length of .each step operation (5
millisenconds). At the end of the
last step 35 milliseconds is added
to allow the head/carriage assem-
bly to settle.
Diskette RPM Monitor. The adapter
monitors the pulses from the light
emitting diode/phototransistor.
Access Line Encoding. The. adapter·
card provides the correct combina-
tion of signals required to step
the head carriage in the correct
direction.
Head Load Operation. The adapter
activates and deactivates the head
load solenoid.
Error Sensing/Corrections. Error
condtions are sensed, and cor-
rected if possible, by the adapter
card. Error conditions not cor-
rected are relayed to the system
card in the form of interrupt
requests.
Interrupt Request. The adapter
card uses this line to signal the
system card that the diskette
drive needs attention from the
system card. Drive status pro-
vides the input to interrupt
request.
Serialization-Deserialzation
(SERDES) of Data. Data is trans-
mitted between the system card and
the diskette adapter card through
eight data bit lines at the same
time and received at the card as
parallel data. The SERDES circuit
converts the parallel data to
serial data.
7-14 IBM Displaywriter Product Support Manual