The DOS/Win/Win95 driver

The best way to handle this interface is to write a device driver but it's a hard job, so for the moment I wrote only an MS-DOS program (in Borland Pascal 7.0) that is not memory resident.
I launch it in an iconized DOS session under Windows 95 (works also under Windows 3.xx), and, once received the correct time and set the system clock it exits. I added a link to it in the startup folder, so every time I boot my PC the clock is synchronized in a few minutes. Since only one bit per second is received the system is not overloaded. This is not an elegant solution, but it works.

Here are the command usage and the command line arguments:

Use:    DCF77 [ COMx | Pyyyy Izz ] [ -sync [ -ret ] ] [ -nochk ] [ -notmout ]

Where:  x         is the COM port number (1..4) of the receiver (default COM2)
        yyyy      is the I/O port number (hex) of the non-standard COM port
        zz        is the IRQ number (dec) of the non standard COM port
        -sync     sets the real time clock of the PC after having decoded
        -ret      returns to DOS after having synchronized the clock
        -nochk    skips IRQ busy checking (use carefully)
        -notmout  skips timeout checking (use when reception is difficult)