#prodos

"The "Professional-1541-DOS" from Mikrotronic System is an add-on for the 1541 and a C64 or a C128 in C64 mode, which is supposed to speedup all read- and write-operations of the drive. The Professional-DOS is an expansion for an already installed speeder with a parallel cable, like SpeedDOS, SpeedDOS Plus, Floppy Flash User System and Floppy Flash Toolkit System."

"The Professional-DOS Floppy-Speeder from Mikrotronic for the Commodore home computers C64, C128 and C128D and it's peripherals C1541, C1541-C and C1571 was one of the Super-Floppy-Speeders. This class of speeder systems were mostly equipped with hardware modification boards and a parallel cable of course. Well known products are Dolphin-DOS from Dolphin-Software, Prologic-DOS (Classic) from Jann Datentechnik, Turbo-Trans from Roßmöller and Professional-DOS from Mikrotronic."