Hp 98546 Display Compatibility Interface; General Description - HP 9000 Series 310 Service Information Manual

HP 98546 Display Compatibility Interface
General Description
An HP 98546A Display Compatibility Interface enables bit-mapped video from the computer to
be compatible with the HP 35721, HP 35731, and HP 35741 monitors when one of the following
operating systems is used:
• HP Series 200 BASIC 2.0, 2.1, and 3.0.
• HP Series 200 Pascal 2.0, 2.1 and 3.0.
The two video cards included are exchange assemblies and nlay be individually replaced. Parts
of this interface are:
• Video Card, 98546-66570
• Graphics Card, 98204-66577
• Various Video Cables
Both cards are installed in adjacent slots. The video card must be in an I/O slot with the
graphics card in the accessory slot directly above the video card.
This two-card set has the following functions:
• Bit-Mapped Video Input
• Katakana or Roman 8 Character font.
• 50 or 60 Hz Refresh Rate Selection
• Alpha and/or Graphics Video Output
Figure 3-14 and 3-15 are block diagrams of the cards. Refer to these diagrams for functional
descriptions.
t - - - - - - + - - O V l D E O .
CaMP. VIDEO
I---._-+--
GHRTC
I---._-+--
GVRTC.
L , - - - , - J - - - - - t - t - - - - - t - - - - - - - - t - - -
AGSYNC
~--+-----------~-~~
Figure 3-14. HP 98546A Display Compatibility Interface (Graphics) Block Diagram
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Functional Description