View Full Version : Using modems and phone lines

June 18th, 2005, 01:32 PM
How do I set up a local network using modems and phone cables (rj-11)? I have a lot of machines that can talk over a modem but very little ethernet capability. Is there a website out there or book I can get for this?


Terry Yager
June 18th, 2005, 02:55 PM
Really, hardwiring the things is as simple as jacking them together with enough splitters to get the job done. The hard part is faking a dial tone & a "ring" signal on each computer. Most modems won't work without one or both of those signals. Some comms software is able to do so. I used to use the modem in my very first laptop (a Zenith SuperSport) to download software from my desktop PC. I don't remember if it was Telix of ProComm Plus that I used, one or the other. Those two were my favorite comm software back then.


vic user
June 19th, 2005, 01:23 PM
oh nathan, i wish you and i were in the same city!

i am way into doing what you are up to.

my approach, is to setup a bbs on one machine awaiting calls, and then use any other machine with access to the hayes AT command set, and dial in using:


this is more or less the method i use to transfer text from one machine to the other, as well as getting .prg files from the internet to my vic 20.

slow but it works.


June 19th, 2005, 01:45 PM
How do I set up a local network using modems and phone cables (rj-11)?

I have a kit I bought a few years back labeled PC Interlink by Softworx of Richardson, TX.

It consists of four printer-port pass-through adapters, each of which also has a phone connector. The other each of each phone cord connects to a junction box.

From the book:

"When PC-Interlink is active, each user can simultaneously:

send printer output to any parallel printer on the system. This allows four computers to use as few as one printer or to have access to as many as twelve different printers, depending on the system configuration.

copy files to or from other computers without disrupting other users.

talk to another user via the chat feature. Chat can be used to inform another user that you will be using their printer, comment on a file you will copy between computers, or even confirm lunch plans."

June 19th, 2005, 05:47 PM
I don't think that a modem will pick up and transmitt over a 'dead' wire. I'm not talking about detecting a dial tone - you can force the modem to go off hook without doing that. I'm talking about generating a carrier and actually connecting to another modem.

Telephone lines have a small amount of current running over them. (During the ring it's a much larger amount, but that is a different issue.) You need to simulate that current. There used to be kits do this - look for 'phone network simulators.

Why hassle with the modem? If you are going to connect two machines with a serial port, use a null modem cable. You can ignore the ATA and ATDs in software if it bothers you. :-)