Welcome to the WA4DSY 56KB RF Modem
information Page!

This is a prototype of the WA4DSY 56KB RF modem. It is intended for use on amateur packet radio networks. The modem generates RF in the 28 to 30 mhz range and requires and linear transverter to convert the signal to a UHF or microwave ham band. The digital interface is synchronous serial. The modem supplies TX and RX clocks. For more details see the various links below.

• PacComm handles ham and commercial modem sales.
• Sound Radio Products sells the Modem and the Spirit-2 PAD
• Email GRAPES at and inquire about special prices for hams .
  Note: Due to spammers harvesting email addresses
  from this page I had to make the email address
  a "non-clickable" png image. Sorry for the inconvience.

Information about the modems

• See a good photograph of the modem (68K)
• 56K modem user guide (cable hookups etc.)
• Hookup diagram for PacComm Spirit-2 Pad
• Technical Paper on original 56KB Modem (1987 design)
• Information on the new 56KB RF Modem (updated Aug. 31 1996)
• Technical Paper on the new 56KB Modem (1996 design)
• Information on the 56KB bit repeater
• Error Correction Coding for the 56KB modem
• 56K modem parts list (10K text file)
• 56K modem tuneup instructions

56K Modem Schematics

• Schematic page 1 of 4 (Power supply and FPGA) Adobe Acrobat PDF file [27K].
• Schematic page 2 of 4 (Transmitter IF) Adobe Acrobat PDF file [19K].
• Schematic page 3 of 4 (Receiver) Adobe Acrobat PDF file [18K].
• Schematic page 4 of 4 (Digital user interface) Adobe Acrobat PDF file [15K].
• Download all 4 pages of the modem schematics (64K zipped Postscript)
• Tango and Gerber CAD-CAM files for the modem PC board (568K)
• Documentation of the original 1988 3 board version of the 56K modem (zip file 105 MB)

56KB Modem Software

• edit56K.Zip A program to edit EPROM data for the new modem (Zipped 44.5K)

• Download customized modem EPROM for use on the Atlanta 56KB user LAN

• PI2DRV10.ZIP OS/2 Ottawa PI card drivers for JNOS and PMNOS
  (Includes driver source and JNOS110) (298K)

• PI2FIX03.Zip Yet another bug fix PI2DRV10 above. New 1-21-97 (44K)

• How to use the PI card with Linux
• How to setup Linux to use the PackeTwin card in interrupt mode
• Download the Linux PI card driver and the piconfig program (.tgz file 30K)
• An alternative Linux PI card driver
• A Linux PI2 & PackeTwin card driver
• Phil Karns DSP page (Reed-Solomon code source)
• Original 1987 3 board 56K modem software collection with state machine / sine-cosine EPROM image

Related Hardware

• List of equipment used in a 56KB station
• Sources of Transverters
• Schematics and documentation for MMT432/28 transverters (605K zip file)
• High speed packet radio equipment list
• Ottawa PI2 Card
• Some Ottawa PI card problems and solutions
• BayCom USB modem

Hi-Speed Networks and modem applications:

• Map of the Atlanta 56K user LAN
• Map of the Georgia 56KB Wide Area Net
• University of British Columbia Amateur Radio Society, VE7UBC 56KB Repeater and Transverter
• 56KB network in Vienna
• 430 Mhz Band Full Duplex 56 KBaud CELLNET Prototype Notes
• "Packet Radio", A page with many packet and spread spectrum related links.

Misc. experimental services

• Current Weather conditions here
• Watch real objects plotted on a map with Java APRS

No Windows programs were harmed (or even used) during the production of this web page.

Links2Go KeyResource Packet Radio Topic