Sdl demos

hi all,

I have compiled SDL lib and got sdl-demos working over Linux framebuffer
driver, keyboard and mouse are responding well with some minor issues.

Currently vga chip supports only [640x480x16] and [640x480x8] modes.
By default framebuffer is running in 640x480x16 and penguin logo is coming

The issue I am facing is when I run following sdl-demos
testkeys, checkkeys, testwin, overlays, overlays2 … all goes fine.

But when I run testpalette or testwm the screen get splits into two and both
demos output comes twice horizontally with distorted color palette output.

Can any one suggest where things are going wrong.