AT&T 3B2/300 Technical Reference Manual page 187

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CM195U STARLAN INTERFACE CARD
The AT&T STARLAN network is a low-cost, local area network for linking MS-DOS and UNIX
system-based computers. STARLAN runs at 1 megabit per second on twisted pair wiring. The wiring
is based on AT&T's Premises Distribution System (PDS). The lowest level protocols conform to the
IEEE 802.3 standard for Carrier Sense Multiple Access with Collision Detection (CSMA/CD) local area
networking. The high-level protocols support applications written for Microsoft Networks.
Connection to STARLAN from a 3B2 computer is provided by a CM195U STARLAN Interface Card
that plugs into a 3B2 computer feature card slot. This card is called a Network Access Unit (NAU) in
terms of STARLAN.
The CM195U Card is a single-width card measuring 6.5 inches wide by 7.4 inches deep.
Figure 2-55 shows the component layout of a typical CM195U STARLAN Interface Card. Connector
pinout information is provided in Appendix B. The major components of the CMl 95U Card are listed
below:
• An INTEL 80186 Microprocessor
• 16K bytes of Read Only Memory (ROM)
• 32K bytes of Static Random Access Memory (SRAM)
• An INTEL 82586 Ethernet Controller (also called a Local Area Network Coprocessor).
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