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MNEMONIC
ATN-L
CEO-L,
CEI-L
CSAO-H thru
CSA5-H
CSBO-H
thru
CSB7-H
CSRS-L
CSWS-L
Theory of Operation
7942 and 7946
Table 3 - 1. List of Mnemonics
SIGNAL
Attention
Chip Enable, Bits
0,1
Con trol/Sta tus
Address Bus, Bits
o
thru 5
Control/Status
Data Bus, Bits
0
thru 7
Con trol/Sta tus
Read Strobe
Control/Status
Write Strobe
SOURCE
AS
-
Al
111
AS
-
AS/A2
81111
AS
-
AS
-
DESCRIPTION
HP - IB managemen t in terf ace line
used to specify how information on
bidirectional Data I/O Bus DIOI-L
through DI08-L is to be interpreted
and which device must respond to the
information.
When ATN -L is low,
the DIOI-H through DI08-H lines
carry addresses or commands. When
A TN - L is high, the 0101 - H through
DI08-H lines carry data.
Enable the read preamplifier/write
driver IC in the head -disc module of
disc drive assembly AI.
DC - IB signals used to access the
registers in a selected DOC which
comprise the Control/Status Data Bus
CSBO-H through CSB7-H. Output to
DOC PCA-A2111 via cable W2.
DC-IB bidirectional 8-bit bus used to
pass control and status data between
the HOC and a selected DOC. Out-
put to DOC PCA A2
III
via cable
W2.
DC - IB signal used to pass bytes from
the DOC to the HOC over Con-
trol/status
Data
Bus
CSBO-H
through CSB 7 - H. The bytes are of a
DOC-status nature since recording
medium information is passed over
Read/Write Data Bus DA TAO-H
through DATA 7 - H. The read strobe
generates a
SOO-nanosecond con-
trol/status bus read cycle. Output to
DOC PCA - A 2
III
via cable W 2.
DC-IB signal used to pass control
bytes from the HOC to the DOC over
Control/Status Data Bus CSBO-H
through CSB7-H.
Output to DOC
A2111 via cable W2.
3-23
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