Sun Microsystems Ultra 5, Руководство по обслуживанию

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B-10 Sun Ultra 5 Service Manual • February 2000
B.6 Parallel Port Connector
The parallel port connector is a DB-25 type connector located on the serial/parallel
connector back panel. The following figure illustrates the parallel port connector
configuration and the following table lists the connector pin assignments.
FIGURE B-6
Parallel Port Connector Pin Configuration
TABLE B-7
Parallel Port Connector Pin Assignments
Pin Signal Description
1 Data_Strobe_L Set low during forward channel
transfers to latch data into peripheral
device. Set high during reverse channel
transfers.
2 to 9 Data[0..7] The main data bus for the parallel port.
Data0 is the least significant bit (LSB).
Are not used during reverse channel
transfers.
10 ACK_L Driven low by the peripheral device to
acknowledge data byte transfer from
host during forward channel transfer.
Qualifies data being transferred to host
in reverse channel transfer.
11 BUSY Driven high to indicate the peripheral
device is not ready to receive data
during forward channel transfer. Used
to send Data3 and Data7 during
reverse channel transfer.
12 PERROR Driven high by peripheral device to
indicate an error in the paper path
during forward channel transfer. Used
to send Data2 and Data6 during
reverse channel transfer.
13
1
14 25