SJD41 (S-JiffyDOS 1541) is an extension for the original Jiffy DOS operating system. SJD41 can be used as a EPROM inside the 1541, but also with emulators, the 1541 Ultimate, or the Turbo Chameleon64. Features: Faster loading and saving. 40 Tracks compatible. GEOS validation and scratching. Extended disk drive status, and much more.