Convert sps to dds Online: sps2dds

You can use Tom's Editor to easily convert images from
Spectrum 512 (smooshed) .SPS to Direct Show Surface .DDS.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

SPS

Spectrum 512 (smooshed) is an image format with extension SPS.

DDS

DDS are files invented by Microsoft to be used in games, mostly as textures. Images can be compressed to save space but the compression methods defined by DDS are all very fast in terms of coding and decoding.