• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Modem to modem connection.

Status
Not open for further replies.

john1

Active Member
Hi,

Can i get a computer to use a dial-up modem,
to ring up another dial-up modem,
and get that other dial-up modem to answer the phone,
and their associated computers to exchange information ?

I have tried to do this, unsuccessfully so far, I haven't
got my head round using a dial-up modem to answer a phone.

Any help would be appreciated,
John :)
 

blueroomelectronics

Well-Known Member
Yes. Your terminal software should be able to handle modems.

I think you use ATA on the answering modem.
 
Last edited:

GonzoEngineer

New Member
:You could also hook two modems together in a loop and make a Perpetual Modem Machine! :D

(Sorry, just couldn't resist that one!)
 

Mikebits

Well-Known Member
Yes. Your terminal software should be able to handle modems.

I think you use ATA on the answering modem.
don't you need loop current in between the modems, usually supplied by the telco?
 

Leftyretro

New Member
Of course you can, however the two modems must be hooked together via POT line or something the emulates it that supports line and ringing voltages.
Hayes AT command protocol can handle all the needed answering/handshacking requirements. This is 80s tech.

Lefty
 

john1

Active Member
Hi Blueroom, Hi Gonzo, Hi Mikebits, Hi Leftyretro,

****************

Hi Blueroom,
short and sweet, a simple yes.
I am pleased about that, as i was beginning to think it could not be done.
My terminal software should be able to handle modems.
Well, i hope it can too.
I will need to locate it of course, in order to find out.
I'm running XPpro, and it has something called a 'Hyperterminal',
but no 'Terminal Software'.

Hang on ...
I think you mean that my PC should be able to use dial-up ...

Why yes, it can.
Thats the first bit done.

Now i will have to google ATA, which might be like 'Hayes',
for the answering modem.
Which will also be connected to a PC.

****************

Hi GonzoEngineer,
A perpetual modem machine. Hmm well the more i read about this ATA there
doesn't seem to be anything self sustaining about it. All the stuff i see has
to be followed by pressing the 'Enter' button.
Which would be difficult.

Where i put that i want the other modem to answer the phone,
that is because i want the ringing tone at the other end,
to cause the other modem to answer the phone.

Its not going to be able to press any buttons, just answer the phone.

However, i might have it wrong.
They might mean that you can use the enter button, to set it to answer.
But they dont say if it will stay like that.
I want it to wait, until i ring it up.
Then answer.

I will have to read through this Hayes/ATA stuff again.

****************

Hi Mikebits,
I think loop current is needed where just two modems are used on a
private-wire. I dont think it applies when using the telephone system.
But my knowledge in this area is a bit thin.

****************

Hi Leftyretro,
Your last post is very encouraging, that the Hayes AT command protocol can
handle all the needed answering/handshaking requirements.

Yes, it is 1980's technology, some 1980's technology wont work in todays
systems unfortunately, but i am hoping that with dial-up modems it will
work fine.

What i want the other modem to do is fairly simple,
I want it to answer the phone,
and allow the exchange of information between the two computers.

I haven't finished reading up about the Hayes AT stuff yet.
Its looking encouraging so far.

Cheers, John :)
 

Sceadwian

Banned
Hayes command set - Wikipedia, the free encyclopedia

With a terminal open to the modem com port on one machine type ATDT <insert other machines number here>
When the phone rings on the other machine simply type ATA
ATS0=1 Will set the auto pickup to cause the receiving machine to pick up the phone after 1 ring.
What you do after you're connected is your own business.

"Back in the day" I used to talk to a friend over a bidirectional file transfer protocol called Hmodem that allowed you to chat with the person you were transferring files with while the transfer was going on. It's so outdated and was used primarily before the Internet was as big is it is now so much so that you can't even find references to it on the net.
 
Last edited:

Leftyretro

New Member
The window of opportunity may have closed a little, but I use to pick up Hayes modems (or Hayes compatible) in thrift stores for $2-5 all the time about 10 years ago or so. I bought them for their nice metal cases and internal power supply components. I must have had 20 or so at one time. A nice cheap way to package home built projects. Some of the newer ones would auto negotiate a baud rate with the far modem up to 14.4k baud while the oldest were straight 300 baud. I would assume you could still find a few for cheap on E-bay and such. Even without using them for data communications they make a neat telephone autodialer with the right PC program.

Good luck with your project.

Lefty
 
Last edited:

Sceadwian

Banned
God's, 300 baud. I can type 1/4 that speed.
 

tcmtech

Banned
Most Helpful Member
Just because I am curious why would you want to use a 14.4 k modems?
I can load a USB port memory device and carry it to a different computer and do file transfers bucket brigade style at about 100 times faster than those the modems can.

My router can top over 85 meg between my 4 computers plus it still can expand to handle 12. And its plug and play.

Like I said, just curious.
 

Sceadwian

Banned
Because as much as modems suck tcm, they still work over any medium that can carry low latency audio. Just about every cell phone in existence has a modem built into it as well, while it's slow speed is an issue they're virtually everywhere.
I somehow doubt your router will work over a wire 6700 miles long (Distance from my location to Japan) while a modem connection is quiet literally just a phone call away.
 

tcmtech

Banned
Most Helpful Member
ah I see! thanks. So what can you get from japan (or any where else) that amounts to anything useful at 14.4K now a days?

Actually one port of my home router goes to the wireless link to my brothers server system and onto the net from there.
I dont know how or anything else but I do know my router makes INTERNET connection possible for me.

I'm a network dummy. I use it but have very littler understanding of how it works. If unplug and wait 30 seconds before plugging it in again does not clear the problem I call for help. ;)
 

john1

Active Member
Hi Tcntech,

I'm not actually sure if your question was for me, but i expect to be using fairly standard type latter-day dial-up modems between myself and the distant machine.
The amount of information required to be solicited from the distant machine is very small, so the modem speed is not really an issue, except that later-day PCs might not work properly with modem speeds less than 28k, so i will be quite happy using (or trying to use) 56k units, or faster.

The intention is that the distant machine will be un-attended, the modem and the PC will turn on at a pre-determined time in the small hours, probably 3:AM
for a short period such as twenty minutes.

During that time the distant modem and PC will await a possible incoming call, and will turn off after the short period whether an incoming call has been recieved or not. This may be arranged to happen twice a week, or as often as desired.
The distant location has no internet connection, but it does have a telephone.

The local machine will be manned. If it is desired to retrieve the information from the distant machine, then that will have to wait until 3:AM (or 4:AM if its BST) then hopefully the distant machine will be waiting for a call, and will deliver the small amount of information to the local machine.

******************

I have read and re-read the replies, but i am still very unsure whether or not a PC and modem can be expected to answer the phone, and exchange a small amount of information.

If the distant machine could subsequently be told to hang up and shut down, that would be nice. But not really necessary.

Regards, John :)
 

unclejed613

Well-Known Member
Most Helpful Member
the distant machine should be set up to go into suspend mode and "wake-up-on-modem" i think XP can do that. the reason for this is that the software on the unattended machine will have to be in a state where it's ready to send data when you call. you might want to see if you can find BBS software that can run on the unattended machine, that way you can browse for the data you need on the machine without having to have a file prepped by hand to be sent. there's some setup and configuration that needs to be done first, but BBS software was what was in use before the internet, and it was quite sophisticated.

edit: i think i found something you can use. it has support for telephone (POTS) bbs serving
http://www.synchro.net/
 
Last edited:

john1

Active Member
Thank you Unclejed,

I have downloaded the one at the top of the page, the installer.
It took a while to D/l i think it was from the guys own machine.
However i could not find anything in their descriptions which said it would run via Post Office Telephone wiring. (POT)

Dont really know how those old BBS systems worked at all ... surely if the line was in use, the next caller would get a busy tone, and have to call back ?

Unless the BBS had some queuing system for callers, then fed the info out to them all at once ... ?

I will look through it to find out what i can, but its late here now and i must get to bed,

Regards, John :)
 

Sceadwian

Banned
Yes John, if it was busy you had to call back. But there was a network instituted, called Fidonet, which allowed people to log on briefly transfer updated forum style posts and then log off. A similiar network was in place for various hubs to transmit their collected posts to other machines which formed the fido net. Fidonet pretty much expired in the last few years, although I'm sure there are diehards out there that still use it. Toward the end of the dialup BBS's useful life it went multi-line with phone banks and serial port octo-boards feeding multiple modems, and the dialup centers of modern ISP dialup connections still use very advanced single chip versions of this, with each 'blade' feeding huge banks of on chip modems.
 

futiller

New Member
Well i think I can solve tihs problem:

You can download FUTIL and Binkleyterm. With this and two PCS you can simulate Modem to Modem connections.

You can try tihs if you want to.

Here are the Readme from FUTIL:

FUTIL FOSSIL Companion
Version 1.10

Usage:

FUTIL has only two possible command line parameters.

FUTIL [/Pn] [/U]

/Pn Install for port 'n' (0-16), default is port 0 (COM1)
/U Uninstall from memory, if already resident



FUTIL - What is it?


FUTIL is a small TSR (terminate and stay resident) utility which
acts as a wedge between FOSSIL and a FOSSIL aware application
(such as a mailer or BBS). Using keyboard commands, you can
simulate modem return codes and FOSSIL status information to
'fool' the application into thinking that it has connected,
received carrier and has a remote user logged on. This is very
useful while setting up a new BBS, or to simulate a modem to
modem connection with two locally hard-wire connected machines.

FUTIL fools the application by providing the means of intercepting
FOSSIL calls, optionally 'eating' transmitted characters,
returning modem result and connect codes and manipulating various
modem status information returned by a FOSSIL. All result codes
and status changes can be entered and manipulated from the
keyboard.

FUTIL is known to work with BNU and Opus!Com. It will normally
work with X00, excepting where an application uses the "x00" high
level language interface to bypass INT 14H and call the driver
directly. Therefore use with X00 is not recommended (but will
usually work).

In thory, FUTIL should work with just about any other FOSSIL in a
100% PC, PC/AT or PS/2 compatible under MS-DOS.




hyperShare.de - upload your files for free - kostenlos Dateien bis 800mb hochladen


So you just need two Pcs and a Nullmodemcable.
 
Last edited:

john1

Active Member
Hi Futiller and welcome to these forums,

Thank you for your interest in my problem, and i have downloaded the ZIP which you placed at the 'Hypershare' files site.

It is late into the night here where i am at the present, but i will take time over the next few days to read up on this stuff.

It is possible that you have not seen the earlier posts which outline what i am trying to do, so i will set it out for you, so that you can see that i am trying to do something which seems very simple.

****************

What i want the distant modem to do,
is answer the phone,
and send a small amount of information,
as an answer,
dictated by its associated PC.

****************

The distant PC and modem are many miles away, in Cornwall.
The local PC and its modem are here with me.

I will of course try to get this arrangement to work locally using PC and a modem here with me, so that i can set it up to operate unattended and i can adjust as necessary so that it works.
So far i have been unable to do so.

I had thought that the modem contained all that was needed for this.
Maybe i was wrong about that.

Yes i am still trying to do this.

John :)
 

carmusic

New Member
good luck connecting over a modem to japan, i tried faxing documents to china and there is so much delay on the line that it only works at very low speed . i have a project that i control from internet (remote computer control) from canada to morocco and it is a lot faster and almost no delay. (maybe 300-400ms max)
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top