1.1. Introduction

The ACP Modem for Linux is a software based modem. Support software for the ACP modem is composed of a loadable kernel module and a user level application. Together these components support direct connection to public switched telephone networks (PSTNs) and support selected countries world wide. Refer to Section 6 of this document for the supported country list.

The modem also supports the standard communications port interface (ttySx) and is compatible with the Hayes AT Command Set.

ACP Modem software is continually under development. If you encounter bugs or usability issues, please contact us and we'll work to correct them.

1.2. Credits

This Linux ACP Modem driver was ported from the Windows NT™ version of the driver available from IBM. Many thanks to Keith Frechette, Charles Ball, and Frank Novak for their technical and support efforts in making this project possible.

1.3. Where Can I Get the Latest Version of this Driver?

The latest version of this driver is available from http://www.ibm.com/linux/ltc/

1.4. Are There Any Other Resources?

Thomas Hood's Debian GNU/Linux on IBM ThinkPad 600 and 600x page contains lots of useful information.

1.5. Copyright Notice and Disclaimer

Copyright (c) 2002 IBM Corporation

This document may be reproduced or distributed in any form without prior permission. Modified versions of this document may be freely distributed, provided that they are clearly identified as such, and this copyright is included intact.

This document is provided "AS IS", with no express or implied warranties. Use the information in this document at your own risk.

1.6. Which Systems are Supported

This version of the ACP Modem driver supports the IBM Thinkpad™ 600E, 600, and 770 that include on-board ACP modem hardware.

1.7. Features of the Modem

The ACP Modem provides the following features:

• Standard asynchronous COM port interface (NS16550A UART compatible) operation

• Bell-103/212A, CCITT-V.21/V.22,V.22bis protocols with data from 300 to 2400 bps

• CCITT-V.32 protocols with data rates of 4800, 9600 uncoded, and 9600 bps Trellis coded (Optional)

• CCITT-V.32bis protocols with data rates of 4800, 9600, 12000, and 14400 bps (optional)

• ITU-T V.34 protocols with data rates from 2400 to 33600 bps.

• 56K capable modem

• Hayes AT Command Set compatibility

• DTMF and pulse dialing

• Asynchronous error recovery protocol

• Error correction via Microcom Network Protocol (MNP) classes 1-4

• Error correction via the V.42 error correction standard

• MNP class 5 for up to 2x data compression

• V.42bis for up to 4x data compression

• "Adaptive Rate Negotiation" which provides for "Fallback / Fallforward" as line quality deteriorates or improves

Your modem contains 56K technology. To take advantage of this technology, you must first make sure that your Internet Service Provider (ISP) supports a 56K modem protocol. Significantly higher modem connection speeds, up to 56kbps, require all-digital transmission connections from your ISP to the line card in the central office from which your phone line is connected. The actual connection rate may be limited by the quality of your telephone lines. Telephone line quality may vary from location to location. Current regulations limit maximum trasfer rates to 53K. While your modem contains 56K technology, typical maximum connection rates in the receive direction may be significantly less than 56K. Currently, 56K capability is for the receive direction only. The transmit direction uses V.34 technology.