#Null modem help?
5 messages in this thread
I'm interested in connecting my A3000 to my 386 via null modem cable for file
exchanges that are too big to fit on a floppy; but I have no idea how to use a
null modem cable. Any advice would be greatly appreciated. Thanks, John.
John,
Using a NULL modem/cable between two serial ports of like wiring will
allow one serial port to act as host and the other as remote (or
answer/receive).
Basically, the null modem crosses the send and receive wires of the serial
port so that the send signals of one go to the receive of the other… in
this way, you can run terminal software on each computer and begin a file
transfer using a common protocol, without having to connect each computer
to a modem (modulator/demodulator).
I believe that the A3000 serial port pinouts are compatible with those of
standard PC's (SOMEONE CORRECT ME IF I'M WRONG, PLEASE) so all you need do
is hook up the NULL modem cable, run terminal software on each computer,
choose a common protocol and parameter settings, set one to RECEIVE and
one to SEND… and start your file transfer.
Thanks, Michael. I'll give it a try. John.
John, Be careful on the serial port of your A3000, there is +-12 Volts and
Audio IN/OUT lines. These lines could cause problems and/or burn something up.
Here is something to try first.
Amiga DB25 PC-AT DB9
2 ————— 2
3 ————— 3
7 ————— 7
or Amiga DB25 PC-AT DB25
2 —————– 3
3 —————– 2
7 —————– 7
This is a minimal config for a null cable. If you want to try a commercial null
modem cable please double check that the pins used are not the +-12Volts or the
AUDIO IN/OUT lines.
Try a Serial Printer cable or Serial Plotter cable (these are null modem cables
actually) or you may be able to find a cable specifically setup for null modem.
The pins in question are Pin 9, 10, 18, and 11 . Good Luck -Steve (DOuble check
these pin numbers, Page B-3 in A3000 book)
John,
Just run over to Radio Shack and pickup a NULL Modem adaptor. I have
used a couple of them on my home systems to connect between two Amigas.
Price is around 4 bucks.
"May the Warp be with you!" (c) 1993 Michael McCormick