I have two PCs with Ubuntu 10.4 and DOS 5.0, which are connected with a 9 pins serial cable.
I need to copy some files from the Linux box to the DOS box.
I tried UUCP but it's too difficult and i didn't found a working client for DOS.
Can you help me? Thanks for any reply!
ftp doesn't work ?
install winscp on your DOS machine, and customise an entry to connect to the unix machine from which you want to get the file...
Check with your network admin if there are limitations regarding the machine who should initiate the connection
There isn't any LAN. My PCs are connected by a serial cable.
so you can connect them together : this will be a Local Area Network 
configure them in the same range of IP or fix their network config so that they can ping eachother
make sure the windows firewall doesn't block youy connection in a way or another ?
Oh my good!
Ok, first of all I would strongly suggest any other form of transfer than serial. But it depends on how much You want to transfer, in which direction or whether learning about serial communication is the main objective of Your undertaking, rather than just copying some bytes.
And we need to know more. Does Your DOS-machine have floppy, CD, USB, (I assume it doesn't have a network card?), is it very old ;), does it have any Windows 3.* on top of it, does it have to keep running DOS5, will You use it as a (serial) terminal to the Linux-machine, have You as of now had any working contact over serial... and so on.
Because this will let us know more about what options are available.
Best regards,
Lakris
First of all, thank You for your help Lakris!
I absolutely need the direct serial transfer: the pc is really old and it doesn't have usb, cdrom, network card, nor ethernet port. Only a floppy drive. It have got Windoze 3.11 and DOS 5.0. I cannot put linux on it! Too old (486, i think)
And yes, I use it as a serial terminal to the Linux Machine. I'm using KERMIT to do that.
To ctsgnb: No, this isn't a LAN, and there is no network.
Why are you not using Kermit to transfer the file then? Kermit has excellent builtin file transfer capability. In fact file transfer was the original purpose of Kermit; other capabilities like terminal emulation came later.
Cool! I didn't knew that! Thanks a lot! 
But I wonder if I have to install KERMIT in the Linux PC... Is the package "ckermit" what I need?
Right, fpmurphy, just what I was planning to point out, given the answers
mgis, Have You examined the options in Kermit? Once You're connected to the host (Linux) with a command line interface, You can initiate a transfer, and then return to Your client (Dos) with a special key sequence and locally give the command for start receiving data. Have You tried that? Or is that something You didn't know of?
/L
PS Sorry, I had to restart my 2400 baud modem and missed some... Yes You need to have kermit software on the host and I guess ckermit is a good choice. You start it at the host (kermit), and type at its prompt something like send <file>, return to Your client with a key sequence that I can't remember (it was something like Ctrl-] I think) but of course You'll find it in the docs of ckermit.
It works! Thank you for your helpful suggest. I didn't knew that KERMIT may transfer files! If anyone is interested; I done the following.
On the receiver (DOS)
[C:\KERMIT] MS-Kermit> set speed 9600
[C:\KERMIT] MS-Kermit> set port COM1
[C:\KERMIT] MS-Kermit> server
On the sender (GNU/Linux - Unix)
# kermit
(/root/) C-Kermit> set line /dev/ttyS0
(/root/) C-Kermit> set speed 9600
(/root/) C-Kermit> send <here_goes_file_to_send)
(/root/) C-Kermit>
Now the DOS pc shows a bit of garbage, but the files is safely in the C:\Kermit directory
Thanks again!
Great, I ponder to much over my writing and there You go finding it all out by Yourself
Yes there's a server mode as well...
Good luck with copying!
/L