SERIAL DOOR
RELEASE 1.0
USER'S GUIDE

1.0 OVERVIEW
Serial Door is a program that allows to transfer files directly from one computer to another, using a serial connection. It has been designed to work with heterogeneous systems, both equipped with a RS-232 serial port. The mechanism works by launching Serial Door on both computers, connected to each other via serial port (e.g. with a null modem cable), and managing both ends of the communication with just a few settings (essentially, the port to be used and the transfer speed). The mechanism implemented has been designed to be as simple as possible, so is not reserved to advanced users.

Serial transmission is notoriously slow (maximum 14 Kb/s), but Serial Door helps to operate in some situations, where is needed or useful to:

- Exchange files with an old system who haven't a LAN connection, nor have USB ports, but only a serial port
- Exchange files between modern systems through USB ports, avoiding to use a LAN connection or USB data storage
- Exchange files between virtual machines, and them aren't sharing files through a real / virtual LAN, but emulating serial ports

1.1 RELEASE NOTES
Serial Door is released as freeware and can be distributed in every non-commercial form.

THIS SOFTWARE IS PROVIDED "AS IS", WITH NO EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO THE LOSS OF DATA, OR PROFITS; USER USES IT AT HIS OWN RISK. ANY FORM OF REVERSE-ENGINEERING OF THE PROGRAM IS PROHIBITED.

1.2 SYSTEM REQUIREMENTS
Serial Door version contained in this archive is intended for the use on Amiga computers, equipped with 68020 CPU or better, and RapaGUI plugin installed. Other software components (e.g. libraries) may be mandatory.

1.3 INSTALLATION AND EXECUTION
To install program, it's sufficient to unpack archive in any directory. To uninstall program, its folder must be deleted. Serial Door must be present on both systems involved in a file transfer, so is mandatory to install it on each of them, taking the correct version from the official page (see "Links" section later in the document).

2.1 FILE TRANSFER PROCEDURE
This section explains the procedure to transfer a file.
1) Launch Serial Door on both computers.

2) Connect the serial ports of the two computers with a proper cable.

3) In the "Serial Port" field, enter the serial port to be used on each Serial Door instance, which will be the ones to which the cable was connected in previous step 2).

4) Decide the baud rate to be used and set it using the "Baud" dropdown box on both instances of Serial Door. The baud rate must be the same on both systems. If erroneously different baud rates are chosen, the transmission may not work properly.

5) On the receiving computer, select where to save the incoming file by pressing the "Browse" button and browsing through devices and folders.

6) On the receiving computer, press the "Receive file" button. The status bar will show the message "Waiting file from remote system...".

7) On the computer who sents the file, press the "Send file" button. Do not reverse this step with the previous step 6). The "Receive file" button on the receiving system must be pressed before the "Send file" button on the other system. Browse through files and folders to select the file to be transferred. Once you have made your selection, the transfer will begin. The status bar on the sending computer will display the message "Sending file to remote system...", while the status bar on the receiving computer will display the message "Receiving file from remote system...". A progress bar will indicate transfer's progress on both computers. Wait for the transfer to complete. When finished, a confirm message about successful transmission/reception will appear on both instances of Serial Door running ("File [...] sent" on the sending side, "File [...] received" on the receiving side).

Return to point 6) to transmit other files in the same way, or to other points prior to 6) to modify one or more transmission parameters.

2.2 OTHER FUNCTIONALITIES
To quit program when finished, user can select "Quit" option under "Info" menu (or, alternatively click on close gadget).

To read main info about the program, user can select "About Serial Door..." option under "Info" menu. 

2.3 TROUBLESHOOTING
The following tips are provided if can be helpful after some problem arised during a file transfer.
- If an error 'Error loading plugin "RapaGUI.hwp"!' is raised, check if 1) RapaGUI plugin is installed, and 2) MUI is installed (is requested by RapaGUI). If error persists, try to place "RapaGUI.hwp" file into program's directory.
- Double-check that the serial ports typed are correct; on modern systems, is possible to check which ports are installed on the system in use and identify where USB-serial adapters have been connected.
- System's serial port settings may interfere with communication, if are mismatching those of Serial Door. Open Workbench "Prefs", then Serial preferences, and check that the parameters saved are: 
	- Input buffer size: 2048
	- Handshaking: None
	- Parity: None
	- Bits/Char: 8
	- Stop bits: 1
NOTE: A buffer size greater than 512 helps when an high baudrate is selected. 2048 is the safest choice because is the same size used into Serial Door. A buffer size of 512 bytes is sufficient for a speed transfer of 9600 baud or lower.
- If an high baud rate has been selected, try again with a slower speed.
- Transferring files to a Linux system, the transfer may fail because user logged haven't write permissions for the destination folder, then is impossible to write file.
- USB-serial adapters require drivers; if you are using them, check that they are correctly recognised by the system.
	

3.1 LINKS
Serial Door official page:
https://www.dl-corner.it/software.aspx?quale=8

The RS-232 standard:
https://en.wikipedia.org/wiki/RS-232

Null modem communications:
https://en.wikipedia.org/wiki/Null_modem

3.2 ABOUT THE AUTHOR
Domenico Lattanzi is an IT engineer, graduated at Rome's university "La Sapienza".
He can be contacted to this email address: domenico.lattanzi@mailfence.com

