FCBS

Specifies the number of file control blocks (FCBs) that MS-DOS can have open
at the same time. You can use this command only in your CONFIG.SYS file.

A file control block is a data structure that stores information about a
file.

Syntax

    FCBS=x

Parameter

x
    Specifies the number of file control blocks that MS-DOS can have open at
    one time. Valid values for x are in the range 1 through 255. The default
    value is 4.