FreeBasic Bare Bones: Difference between revisions

Basic uses an borrowed trick to tell us the end of the string. After the last character, there will always be a 0. So if we read a string in order, we can tell when it has ended.

 

Sub PrintString(src As Byte Ptr, x As Long, y As Long)

wend

End Sub

 

To conclude, this function prints a string (a converted Byte Ptr string). It creates a pointer that is aimed at the [[Text UI|video card]] (it occupies among others a range starting from address B8000 hex), and we pick a location in there. Next we take a character from the string, check if its 0, and if it isn't, copy it to the video card and go to the next character. Due to the way the video card works, we add a color (15) as well.

=== kernel.bas ===

<!-- GeSHi is *broken*. don't use freebasic as language here !-->

Declare Sub PrintString(src As Byte Ptr, x As Long, y As Long)

Declare Sub main ()

wend

End Sub

 

=== link.ld ===