System Expansion Connector; Disk Drive (M1700A And M1701A Only) - HP PageWriter XL M1705B Service Manual

RFE DATA
SRAM 32K x 24
-ROM P.M.
RFE CLK
BUFFERED DATA
LATCHED ADDRESS
Figure 5-8. Digital Signal Processor Block Diagram.
System Expansion
The system expansion connector, J12, provides the CPU signals and
Connector
power sources required by the preview display assembly. The pin
assignments for this connector are listed in Appendix A.
Disk Drive
The disk controller on the CPU assembly (see Figure 5-9) provides
(M1700A and M1701A
the interface to the system data bus for the S.&inch disk drive. The
only)
disk drive connects to the CPU assembly through two connectors,
514 (disk power) and 515 (data and control signals). Pin assignments
for these connectors are described in Appendix A.
BUFFERED
DATA
J
I/O CONTROL
V
INTERRUPT
4
DISK
CONTROLLER
IC
WRITE DATA
-I
READ DATA
CONTROLS
STATUS
1
DISK
DRIVE
M 1700-07
Figure 5-9. The Disk Drive and its Control Circuit.
Theory of Operation 5-15