Valid Fits File

Hi Friends,

I am completely new to these FITS files.Its quite confusing.Can any
one please help me.

I am looking for the code which creates a valid FITS file.The FITS
file should contain a valid header with header test data. The FITS file
should contain one valid image with a test pattern. This image should
be 128 pixels wide by 64 pixels high. Each pixel should be eight bits.
Pixel values in the first row should begin with 0 and increment by 1.
Pixel values in the second row should begin with 1 and increment by 1.
Pixel values in the third row should begin with 2 and increment by 1.
Etc.

Hope someone helps me out.

Thank you very much,

Regards
Kiran