Cdspc-Ctrl Card; Cdspc-Video Card - HP M2350A Service Manual

Understanding the Computer Module
The Function Cards
The CDSPC is similar in operation to the DSPC, with the exception that the video RAM is three
times larger. For this reason the CDSPC consists of two cards, as follows:
CDSPC-CTRL card
CDSPC-VIDEO card
All display data, including local language characters and color information, are produced by the
CPC and transferred to the CDSPC via the MPB.
Note
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The Japanese character set is too large to be dealt with on the CPU, so these
characters are stored on a local EPROM card which is placed in the same
cluster as the display controller cards CDSPC-CTRL and CDSPC-VIDEO.
The CDSPC cards only control the mechanism of actually displaying information on the screen.
The function of the CDSPC cards can be simply divided: the CDSPC-CTRL card is the master
card that interfaces between the system, via the MPB, and the CDSPC-VIDEO card. The
CDSPC-VIDEO card is a local card which contains the Video RAM and output stage to the
display.
CDSPC-CTRL Card
The CDSPC-CTRL card is based around a 68000 microprocessor. It also contains the MPB
Interface to access the display data and both a RAM and a PROM to run the firmware for
communication with the CDSPC-VIDEO card.
CDSPC-VIDEO Card
The CDSPC-VIDEO card is connected to the CDSPC-CTRL card via the local bus. It contains the
Color Register which chooses the color, three banks of VIDEO RAM (red, blue and green) for
pixel data, three SLIP Chips, the video buffers and the output to the display.
Connection
The CDSPC-CTRL card must be inserted in the computer module so that the CDSPC-VIDEO can
share the same local cluster.
The CDSPC-VIDEO card must be inserted into the rear of the computer module so it can be
connected to the display. The integral color display is connected via a Q-pin D-type connector
on the card's edge to a similar connector on the rear of the display. A slave display can be
connected to a video output on the rear of the integral display.
If Kanji characters are to be supported then the EPROM, DSPC-KANJI must also be inserted
into the same cluster as the two CDSPC cards.
Each pair of CDSPC cards can support either one Master Display and three Slave Displays or
four Slave Displays
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