 The RT-11 operating system could be booted from, and perform useful work on, a machine consisting of two 8-inch 250KB floppy disks and 56KB of memory, and could support 8 terminals.Other boot options include the RK05 2.5MB removable hard disk platter, or magnetic tape.Distributions were available pre-installed or on punched tape, magnetic tape, cartridge tape, or floppy disk.