i found the solution. According to brand of glcd, time of responses change. For example the glcd which i'm using has 25ns rising and fall time. İf you dont add delay after enable and cs signal, glcd' ...
I have same problem too. My code works perfectly with glcd_update () function. But when i compiled my code without fast_glcd( it is still working in isis) characters in glcd engaging. Can anyone help ...