By default, Blitz looks for info to be loaded in the same directory/folder as where the Blitz program was loaded and run. You may want to create subdirectories (ie folders) inside the one where the program resides.
So, in your case:
Blitzer ;your directory
DataPath ;within the Blitzer directory, new directory called DataPath
Saves ;for game saves
Maps ;for, whatelse? maps!
etc...
When you want to access data1.dat inside DataPath, you would use:
filein = ReadFile("DataPath\data1.dat")
Blitz will start from wherever on your hard drive the directory "Blitzer" is found, and see if it can find the subdirectory DataPath, and looking inside it, find the file data1.dat.
This way, you can always move "Blitzer" around in your hard drive's many folders, and it won't matter where it is, it will always find the data.
So, in your case:
Blitzer ;your directory
DataPath ;within the Blitzer directory, new directory called DataPath
Saves ;for game saves
Maps ;for, whatelse? maps!
etc...
When you want to access data1.dat inside DataPath, you would use:
filein = ReadFile("DataPath\data1.dat")
Blitz will start from wherever on your hard drive the directory "Blitzer" is found, and see if it can find the subdirectory DataPath, and looking inside it, find the file data1.dat.
This way, you can always move "Blitzer" around in your hard drive's many folders, and it won't matter where it is, it will always find the data.