How can I create a raw 16bpp bitmap to burn to flash using LogicLoader?

Open up Adobe Photoshop (or Photoshop CS) and load the original bitmap image intended for use as a splash screen image
Flip the image upside down by choosing Image > Rotate Canvas > Flip Canvas Vertical
Choose File > Save As
Select BMP as the format, choose a filename and select OK.
The Bitmap options window should come up. Select 16bpp and choose the "Advanced Modes" button located at the bottom.
There are two color options determined by Card Engine type
- LH7A40x Card Engines: Choose mode X1 R5 G5 B5
- All other Card Engines: Choose Mode R5 G6 B5
Select OK
Open up the bitmap in a hex editor or text editor in binary mode, and remove the first 70 bytes of information (this is the bitmap header information).
Save the bitmap.