This is the zx7 compressor/decompressor by Einar Saukas.

File "zx7_Info.txt" is the original readme file.

Files "decompress_*.s" are for inclusion in your Z80 assembler program.

Folder "zx7_compressor" contains the C source for the compressor. Compile with:

  $> gcc -o zx7.exe zx7.c compress.c optimize.c

The original zip archive can be found at WoS:

  http://www.worldofspectrum.org/infoseekid.cgi?id=0027996