Some texts in Czech are: konsluho (construction of sundials, without a computer) and sd_hor.htm (explanation of a horizontal sundial). hor_a3_shl is a plot with lengths of shadows added: it may serve to guess the influence of any obstacles, wherever direct insolation is important (solar panels, windows, flowers...).
The source text in Borland Turbo Pascal is contained (including the needed units) in pas_jh_zip (1.3 MB) , the needed BGI drivers for graphic mode are in bgi.zip .
For detailed Czech pages on sundials, see a page from astronomers from Hradec Kralove including online computing of their geometry. My own programme is available online too, through insolation.php here.
Jan Hollan