Marc B. McDonald is an American who was Microsoft's first salaried employee (not counting Monte Davidoff, who wrote the math package for BASIC for a flat fee). He is credited with designing and implementing the 8-bit File Allocation Table file system for the NCR 8200 data-entry terminal and Microsoft's Standalone Disk BASIC-80 in 1977. McDonald also developed an 8-bit operating system called M-DOS or MIDAS; the system itself was never released by Microsoft, but its file system (a variant of FAT) influenced Tim Paterson's QDOS.