file control block
file control block
(operating system)FCBS=x,y
where x (between 1 and 255 inclusive, default 4) specifies thenumber of file control blocks to allocate and therefore thenumber of files that MS-DOS can have open at one time. y (notneeded from DOS 5.0 onward) specifies the number of files tobe closed automatically if all x are in use.