Other commercial machines that used writable microcode include the Burroughs Small Systems (1970s and 1980s), the Xerox processors in their Lisp machines and Xerox Star workstations, the DEC VAX 8800 ("Nautilus") family, and the Symbolics L- and G-machines (1980s). Some DEC PDP-10 machines stored their microcode in SRAM chips (about 80 bits wide x 2 Kwords), which was typically loaded on power-on through some other front-end CPU. Many more machines offered user-programmable writable control stores as an option (including the HP 2100, DEC PDP-11/60 and Varian Data Machines V-70 series minicomputers).