I added a HUGE response with answers, code etc last night but it must have been zapped by the forum problems.
You might have solved your movemouse stuff but this should help.
Second, try (pseudo)...
You might have solved your movemouse stuff but this should help.
Second, try (pseudo)...
while cls setviewport 0,0,graphicswidth(),graphicsheight() Draw border image setviewport x,y,200,200 draw viewport image flip wend