IBM Turbo 16/4 Token-Ring PC Card 2, User Manual

Page: 17 / 123

Chapter 1. Introduction
The IBM Turbo 16/4 Token-Ring PC Card 2 (referred to as PC Card ) is a
credit-card-sized adapter that provides an interface between computers and
Token-Ring networks. It is part of the shared RAM family of adapters. The PC Card
is designed for computers with slots that comply with the standards for the Personal
Computer Memory Card International Association (PCMCIA) Release 2.1, Type II
slots.
Features include:
v
Remote Program Load (RPL)
v
Full-duplex-ready.
v
Supports the Desktop Management Interface (DMI).
v
Easy to install — variable interrupt levels and I/O address choices.
v
Includes RJ-45 cable and STP media access adapter for easy connection to
either UTP or STP cables.
v
Mobile computing possible because the PC Card does not have to be removed;
simply disconnect the cable and reconnect when you are in the new location.
See “Stealth Mode” on page 2.
v
Compliance with PCMCIA Revision 6.2 and IEEE 802.5 standards. This allows
use of the PC Card with a variety of application programs.
v
Auto Ring Speed, a configurable option that permits the PC Card device driver to
detect and operate at the data rate of the ring.
v
Support for a variety of network operating systems and network applications.
Auto Ring Speed
The Auto Ring Speed function avoids problems due to manual configuration of an
incorrect data rate. The function also eliminates the need to reconfigure the PC
Card if the data rate of the ring is changed.
You should not select Auto Ring Speed if you might be the first one to attach to
your ring. The PC Card will not allow you to connect in this case. You will have to
try to connect again after another Token-Ring user is on the ring.
When using the PC Card in Auto Ring Speed mode, it is important to be aware of
transmit buffer limitations that may cause problems. A 16-Mbps Token Ring can
support transmit buffer sizes up to 17 960 bytes. A 4-Mbps Token Ring can support
transmit buffer sizes up to 4464 bytes. This is a restriction due to the speed of the
media. This might affect your application.
If your software is configured to try 16-Mbps ring operation first and you plan to
utilize Auto Ring Speed, use a transmit buffer size less than or equal to 4464 bytes.
This will ensure that you will not have any open PC Card errors due to improper
transmit buffer size if your PC Card must change ring speed.
© Copyright IBM Corp. 1997, 1999
1