HP 330 Service Information Manual page 75

System Interface Board
Human Interfaces
The system interface board is designed to meet most, if not all of the computer's human interface
needs in a single system slot. It integrates RS-232, HP-IB, Audio, HP-HIL, Battery backed real
time clock, LAN, DMA, and an optional high-speed disc HP-IB interface.
To maintain software compatibility, the designs of other interface cards are used. These cards
are the HP 98625B, 98643, 98620B, and the original DIO size Series 300 human interface card.
Each of these four sections of the board operates independently.
The LAN portion of the system interface board is software compatible with the current Series
200/300 DIO card (HP 98643A). Because of space constraints on the backplate, the ThinLAN
implementation of the LAN was chosen. The MAD is built into the card and, with the BNC
"T" connector, connects directly to the thin coax.
DMA is implemented on the system board with a new semi-custom CMOS standard cell. The
chip is features an HP proprietary 1.5 micron CMOS process and is a compatible superset of
the HP 98620B DMA interface card.
High-Speed Disc Add-On
An optional high-speed disc add-on is identical to the HP 98625B. It allows HP-IB word-wide
transfers during DMA cycles and is fully supported by software. Because of limited space, the
high speed disc is implemented on an add-on board and is connected similar to the RAM add-on
boards. This configuration does not require any additional DIO or DIO-II slots.
A special HP-IB cable is used with this add-on and connects directly to the edge of the add-on
board using a special connector.
Monitor Compatibility
Both models support the current Series 300 video boards and display systems.
• 512 by 400 monochrome and 4 plane color.
• 1024 by 768 monochrome and 6 plane color.
• HP 98720 1280 by 1024 Solid Rendering Display System.
• HP 98720H 1024 by 768 Graphics Display Station.
• Series 200 Display Compatibility Card Set.
Functional Description
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