Convert bmp to spu Online: bmp2spu
You can use Tom's Editor to easily convert images from
Microsoft Windows bitmap .BMP to Spectrum 512 .SPU.
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Format created by Microsoft for their Windows and OS/2 operating systems. Images can be compressed or not.
Spectrum 512 is an image format with extension SPU.