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 used to launch it in an iconized DOS session under Windows 95 (works also under Windows 3.xx and, of course, MS-DOS) and once the correct time is received, the system clock is set and the program 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. Unfortunately this solution only worked for the mentioned old operating systems and this program is not able to correctly run on modern operating systems that prevents direct hardwire access. I never found the time to re-write it for modern Windows environments.

Anyway, 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)

• Download dcf77.pas (42,828 bytes): the full pascal source code.
• The executable dcf77.exe file is not included because it will probably not work on your system. If you need it you will have to recompile the source code and use at your own risk.