Winplan uses this file instead of MESSx.DAT to send messages. Sending messages to several people is supported by the file format, but Winplan does NOT insert header lines like the DOS clients as Planets and PCC do ("<<< Universal Messages >>>"). MAKETURN disassembles messages into single commands.
+0 WORD Number of sent messages
+2 17 BYTEs ? (unused, rubbish)
+19 n RECORDs containing the messages. Probably, a variable record size
is possible, but not supported by Winplan:
+0 BYTE unused fill byte
+1 BYTE Flag. If the message is valid, this byte is
31h ("1"). If the message has been deleted,
the value is 30h ("0").
+2 12 BYTEs Addressees, a list of 30h ("0") and 31h
("1") for all 11 races and the host.
+14 WORD Length of message text. In my files, the
value is always 600.
+16 n BYTEs Encrypted message.The message encryption is the same as in MDATAx.DAT, except that line breaks contain both a CR and an LF (0Dh 0Ah, encrypted 1Ah 17h). The message is padded with encrypted spaces (2Dh, "-"). The THost line-break filter is not aware of the additional 0Ah's, so a line must not be longer than 39 characters in a Winplan message.
If a message is deleted, Winplan doesn't truncate the file but copies all messages back some positions and sets the flag at the first invalid message to "0".
If the file is empty (no message has been sent yet) it contains a single zero word only.
Possibly, a variable record size is planned though not implemented in Winplan. Since 600 bytes is too less for a message, PCC can extend the format in this way if it knows Winplan is not installed: Winplan itself would crash reading the file.
Winplan uses the Windows Editor Control. This is a full editor capable of doing automatic line breaks. CR/LF is only in the text if one has really pressed ENTER. If you have written down a complete paragraph, it will contain no single CR/LF, line breaks were only done at display time. This was "downgraded" in later Winplan versions (i.e., ENTER is required) and a host-side filter adds linefeeds after 39 columns.
Winplan uses an ad-hoc conversion for Latin-1 characters (Windows) to MS-DOS characters (cp437): "translate German letters". This conversion is neither perfect nor complete, so best avoid it.
VPA
Internally, VPA can only handle DOS-style message files (MESSx.DAT). When it starts up, and MESS35x.DAT is more recent than MESSx.DAT, it converts the Winplan messages into DOS format. Likewise, when it exits, it converts MESSx.DAT back into MESS35x.DAT. This will break up messages to many people in the appropriate number of unicast messages.
