R.Wieser wrote:
Hello all,

Recently I remembered that it was possible to make a serial connection
between two 'puters and send, from the commandprompt and without using any
(other) programs, a textfile from one to the other. I say "was", as I
can't seem to repeat it between two XPsp3 machines.

Specs:
The machines are connected thru a so-called "null modem" (three-wire) cable
(with the handshake signals wrapped back onto the same conector).

A "mode com1 9600,n,8,1" command has been used (trying to debug the matter)
on both to set up the connection, and "mode com1 /status" returns the same
for both 'puters:

Baud: 9600
Parity: None
Data Bits: 8
Stop Bits: 1
Timeout: ON
XON/XOFF: OFF
CTS handshaking: OFF
DSR handshaking: OFF
DSR sensitivity: OFF
DTR circuit: ON
RTS circuit: ON

The problem:
Both "type com1" and "copy com1 bla" on the target 'puter finish
immediatlily (do not wait for incoming data).

The null-modem connection itself seems to be fine, as I've used a simple
RS232 application which shows the data coming in.

Does anyone recognise the problem and can tell me what goes wrong ?

Regards,
Rudy Wieser

One of the requirements, was to send an EOT character

https://en.wikipedia.org/wiki/End-of...sion_character

so that the connection could close properly.

Now, mine is all cabled up and ready to go. The two machines
already have a serial RS232 interconnect (COM1 == COM3), with a null modem
thingy in the center (connects TX to RX, RX to TX, so
two computers can talk to one another, without shorting a
TX to a TX).

I fired up putty to verify, on the receiving end.
Set baud rate to 57600, enabled RTS/CTS.

On sending end

mode COM1 BAUD=57600 PARITY=n DATA=8 STOP=1 RTS=on
type sample.txt COM1
copy con: COM1
Enter
ctrl-Z
Enter === flushes input at a guess

The problem seems to be mostly on the receiving end.

1) Doesn't seem to have permission to copy COM3 to anything.
2) Does see the ctrl-Z coming across the cable. Closes COPY.

copy COM3 impossible.txt

impossible.txt ends up with "0 files copied" string in it.

The receive end is not at all happy. Could this be
symptoms that "port is busy" ? Probably.

Evidence when receiving in putty, is "it's working to the
best of puttys knowledge". Ownership issues from Command Prompt
seem an issue right now. When putty exist, you'd think COM3
could then be captured by anyone.

So, nope, doesn't work for me at the moment. Situation
"ripe" but "not harvested". All the ingredients seem to be
there, but Clippy has broken it.

HTH,
Paul