Spectrum 512 formats
From Just Solve the File Format Problem
The Spectrum 512 formats are a group of raster image file formats associated with the Spectrum 512 paint program for Atari ST.
Contents |
Format
There are three main file formats:
- Spectrum 512 Uncompressed (.spu)
- Spectrum 512 Compressed (.spc)
- Spectrum 512 Smooshed (.sps)
The image dimensions are always 320×199 pixels, but it seems to be standard practice to interpret them as being 320×200, with an all-black top row.
There are 4 bits of image data per pixel, which are interpreted using a complicated system of color palettes.
For uncompressed (.spu) files, the first 160 bytes of the file should be set to zero. Following that are 31840 bytes of image data (160 for each row). Following that are 19104 bytes of palette data. The total file size is 51104 bytes.