Roland SP-404MK Reference Manual page 118

Customizing This Unit Customizing the Screen Saver
>
Preparing a Screen Saver Image
Create your custom image in the format shown below.
Format Specifications
Image file BMP
format
Size 128 (x) 64 (y) pixels
Color depth 1-bit, 4-bit, 8-bit, 24-bit
Note that only monochromatic images can be displayed. Intermediate colors cannot be
displayed.
Filename screen̲saver̲*.bmp
and
Substitute a number (1‒16) for the asterisk. The unit does not recognize filenames in any other
extension
format. If the filename is not recognized, the default screen saver is shown.