The SEDFS was later bundled with Slogger's own cartridge-based interface and a 40/80-track switchable drive offering up to 400 KB storage per disc, with the bundle taking the Pegasus 400 name, introduced as part of a sales tour towards the end of 1987. This package of interface and drive cost £130. The precise DFS variant used by the Pegasus 400 system introduced "typeahead" support permitting keystroke buffering during disc activity on systems with the Turbo-Driver or Master RAM Board fitted and enabled.