Schematic error is when the program is running correctly, but doesn't do what it should do.
For example, you want to write a program, which will multiply 2 numbers (you won't sell this, it's sure...)
Progam multiply;
Uses CRT;
Var a,b:byte;
begin;
readln (a); readln(b);
writeln(a+b);
end.
Here, the program is fully functional, with no bugs (expect it won't work with number higher than 255), but it doesn't do, what you wanted to do. It's a schematic error (you don't get any error messages, just know it shouldn't do this).
Ooh, question! How can I put GAE fullscreen?