SnapConv is a program designed for use with Spectrum emulators.
It converts between different snapshot formats.

The vast selection of Spectrum emulators which are now available use
a large selection of snapshot formats, and often don't provide any
method for converting between a format which they do support and any
formats which they don't. Whilst there are some snapshot convertors
already available (notably SpConv by Henk de Groot and Damien Burke),
each has its own disadvantages (for example, SpConv can't handle 128Kb
snaps).