Soft Modems:
Structured Design and Implementation

Provisional and Incomplete!

This web page contains material which will support and illustrate a book that I am writing, with the provisional title Soft Modems: Structured Design and Implementation.

• Table of Contents, and how much I've written so far

• An early version of the modem source code

  The code implements the FSK modes and V.29 (fax transmission). Code to implement at least V.22 bis, V.32 bis, parts of V.34, and V.29 (fax reception) exists and will be made available when the book is published, but that code is not released yet.

• Interactive digital filter design page

• Interactive phase-locked loop design page

• QuickTime movies of modem training . . .

  • V.32 bis on a good-quality line   [724 kbytes, 16 secs @ 30 fps]
  • V.32 bis on a poor-quality line   [1.2 Mbytes, 16 secs @ 30 fps]
  • V.29 (fax) on a good-quality line   [121 kbytes, 5 secs @ 30 fps]
  • Explanatory notes