#Amiga->Amiga
15 messages in this thread
Hi All!
Would anyone have any idea how I could connect two modems together, while
NOT using the telephone system?? I have tried but it doesn't seem to
work!
The situation is that we have two Amigas in the same house, about 20
meters apart, it would be two expensive to join em with serial cable
(though a SERNET would be nice!). We are just intrested in trading files
on a regular basis. (One of the machines is running a BBS, the other dials
out and gets files/info for the board)
Any ideas/suggestions are appreciated!
Regards,
Andre
Regards,
Andre Lackmann On AutoPilot and still outta control
Andre,
As far as I know, what you are asking is going to cost you more (far more)
than a serial cable to do the same.
I work for Canon, and we link Fax machines (not my area of expertise) up
in the same office for demonstrations through a simulated PSTN which cost
an arm and a leg!
Get a serial cable and use that! It won't cost *that* much…
Kevin 68030/40 A1200…
Flying AutoPilot from Surrey in the UK
Connect two modems together? If you have modular phone plugs with a
"multiple" connection, just disconnect from the wall, leaving the
computers hooked together "off line", and all should be well.
Next job is to get them talking with "carriers". Load up terminal
programs in each unit. On one machine, command +++ATA, on the other,
+++ATD. This sets up the fiction that one unit is "dialling", the
other is "answering". The terminal programs at each end should report
CONNECT.
At this point, you should be able to type on one keyboard and see
the text on the opposite screen. Still not good enough for
transmitting files, although you could get text through that way.
Best to us an upload/download PROTOCOL. Tell one machine to upload,
the other to download, and find a protocol that both terminal
programs know. The selected file(s) will zoom through.
For text/data files, you're about finished, except that different
machines may use a different end-of-line signal (it's NewLine, or
LineFeed, on the Amiga .. with MessyDos, it's the two-character group
Return-Linefeed). For programs .. well, MS-DOS programs don't work
on the Amiga, and vice versa.
You can transfer data files more efficiently using (a) Cross-DOS, or
(B) a BridgeBoard. You can even go faster bypassing the modems with
a "null modem" cable. But modem-to-modem does work, and sometimes
saves playing with connectors and cables.
–Jim
Jim,
this is priceless information. Thanks!
Brian
bjbart@watserv.ucr.edu
Hi Jim,
We have tried what you suggested, but it doesn't seem to work!
Have you actually _DONE_ this or are you just supposing??
We have been told that a 50meter parallel cable is possible, so we might
just set up Parnet, which would be fantastic!
Regards,
Andre Lackmann On AutoPilot and still outta control
I do the modem hookup several times a week to exchange data between the
Commodore 64 and the Amiga. The 64 end has a 1670 modem; the Amiga has an
Amiga modem 1200 RS. Disconnecting the two of them from the telephone line,
but leaving them hooked together, allows data transfer with excessive fiddling
with edge connectors or cabling.
It has been noted elsewhere in this thread that some modems need to see a DC
voltage supplied on the line connector; the same message gives details on
hooking up a 9V battery to provide this.
Bypassing modems with a null modem cable gives greater speed, but in the case
of a 64/Amiga hookup, a direct connection would need a strange cable and some
electronics to convert TTL levels.
I have not personally used PARNET, but several users who do tell me it works
fine. Keep in mind that many users need the parallel port for their printer
connection, so that PARNET might be more than just a cable; some kind of switch
may be needed.
–Jim
AL >>Would anyone have any idea how I could connect two modems together,
while NOT using the telephone system?? I have tried but it doesn't seem to
work!<<
Ok, you can hook the two modems directly by running the phone cord
directly between modem bypassing the phone company. However, the
phone company also provides power over one of the lines to power the
phone. This is why the phones still work when there is a local
blackout.
Some modems also provided enough power to allow direct connect to
another modem, but some don't. If you need more power try this:
Get a 9 volt battery (the type used with clock radios). Cut the RED
wire of the phone cord, and splice the battery into the RED wire. One
half of the wire to the positive, the other half to the negative – so
the transmissions pass through the battery.
Only the RED & GREEN wires are used for most phones, the BLACK &
YELLOW are spares for a separate line.
You might be able to find a 9 volt battery connector (clamp?) at
Radio Shack, or out of an old radio. Slicing the RED wire with the
connector will allow easy replacement of the battery.
You will need to set one term/modem to auto-answer (ATA), then call the
other term/modem with a simple "ATD". If you have high speed modems, you
may want add the extra options to the dial string. The phone number is
only needed by the phone company to route the call to the other modem.
Have you tried the Public Domain network program ParNet? I have not used it
personally but know someone who has and apparently it works well. You have to
use a special cable, but you can access a hard drive in one Amiga from the
other and visa versa.
Dale,
ParNET (especially the ParBENCH version) is very easy to set up and nifty
to use. But I thing in Andre's case the 20 meter run couuld be the
problem.
As for the cable, I bought a parallel cable that turned out to be wired
correctly when I got the covers off and checked. SO I don't think the
cable is real special. Just needs to have row particular pins jumpered in
both connectors and some cheaper cables apparently only have it at one end
or leave some conductors out.
wmc – via Autopilot!
at 20 meters, just about any solution you go for is going to need top
quality cable and probably and amplifier. I forget what the ethernet
limit is, but for serial and parallel I think it is about a 15-20 foot run
after which you need some signal conditioning and energy boost.
I run a 25' parallel cable and a 25' serial one too, to an A600, and get
both ParBench and Null Modem to work fine.
Bruce Johnson
-via AP
But thats a lot shorter than 20 meters. And I think the shorter length
I mentioned is a limit mentioned in the standards beyond which
performance is no t guarunteed to be better than some specifed error
rate. (Your milage may vary kinda thing) But, since it was 4 years
ago that I was looking at them, and I was looking at the MIL-STD
versions I may have mis-remembered the number or be using the hostile
environment military "thou shalt not" number. But for some reason
15 feet sticks in my mind. Need to find someone with the RS
standandards handy.
wmc – via Autopilot!
Wayne,
I recall seeing a parallel cable amplifier down at the local office
supply store. It takes the signal, amplifies it, and puts it out on
standard telephone wire and then translates it back on the other end. As
I recall, it was good for a couple of hundred feet, at least. Perhaps
this might help?
Brian
bjbart@watserv.ucr.edu
That sounds like the surest way to run a long parallel line to me. But
then, I aint no EE. Just a software engineer whose spent many years
sorting out the, "hell no, can't be the hardware causing this porblem,
gotta be the software…" type discussions that inevitabley come up when a
system starts to hic-cup or barf.
wmc – via Autopilot!
We use boxes that we call 'short hauls' for such situations at work.
Actually, we use them for going between floors in a high rise but
they're no more expensive than modems. Of course, we use in-house
dmarks but, that doesn't mean a long twisted pair wouldn't work.