Specifications

Little Board/P5i Technical Manual
3–26
3.12.3 AUI Installations
This section discusses the guidelines for installations that use the AUI port for connection to an external
transceiver device.
You can connect the Little Board/P5i to a LAN through the standard Adapter Unit Interface (AUI)
connection. The AUI connects to an external device such as a hub, concentrator, or MAU. The AUI
enables you to connect your node to fiber optic, thick net cable, or other Ethernet media via an external
transceiver.
Cables and Connectors
The AUI interface appears on a 10-pin ribbon cable connector. You can attach an optional transition
cable (available from Ampro) consisting of a female 10-pin ribbon cable connector on one end and a
female DB-15 on the other.
3.12.4 Using Network Operating Systems
The most common method of using the Little Board/P5i Ethernet LAN interface is by means of a
“network operating system.” In some cases the network operating system is part of the computer’s
operating system. In other cases (as with DOS and Windows 3.1) the network operating system is
provided separately. One example of a network operating system for DOS is Novell’s Netware, which
supports client-server communications. That is to say, a central computer that runs Netware as its
network operating system provides file server and network services to systems (clients) connected to the
LAN. Each client must also have a compatible network operating system installed .
Modern network architectures are based on the OSI model which defines layers of software between the
network hardware, the network operating system, and the applications that use the network services. At
the “bottom” level is the actual Ethernet cable and the hardware interface, in this case, the Little
Board/P5i LAN interface. A driver is used to talk directly with the hardware, masking differences in the
hardware from the layers above it, including the network operating systems. Several network operating
system drivers compatible with the Little Board/P5i’s LAN hardware are provided on the Utilities
diskette that is included with Little Board/P5i Development Kit. New drivers or new versions of existing
drivers are made available on Ampro’s Technical Support bulletin board. The driver is the only unique
software needed to use the LAN interface. The supported network operating systems provide the other
layers in the OSI model.
3.12.5 Manufacturer’s Ethernet ID
Each manufacturer of Ethernet network adapters and interfaces is assigned a unique manufacturer’s ID by
the IEEE Standards Office. A network address consists of 48 bits. The upper 24 bits are the
manufacturer’s ID and the lower 24 bits are the board’s unique ID. Each Little Board’s Ethernet
controller ID is displayed on SETUP screen 3.