Symbol PDT 3400 Series, Руководство по продукции

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5-2
PDT 3400 Product Reference Guide
DEVICE = driver.ext
This command causes a device driver to be loaded either low (into TPA) or high (into UMBs).
FILES = n 8
≤
n
≤
255
Controls the number of files that DOS can open at once. The larger this number, the more
memory DOS allocates for file handles. The default is 8, which is generally inadequate for
most applications and environments. Allocating too many files wastes memory; allocating
too few files may cause an application or environment to fail if it attempts to open too many
files. Unless there is a specific requirement for more files, we recommend using a value of
n=20.
INSTALL = file.ext
This command loads a TSR from CONFIG.SYS. This command can be used to load TSRs
(low only) that go along with drivers (as a convenience). Note that DOS does not load the
TSRs until the end of CONFIG.SYS (as opposed to where they appear). If you use your
application as a shell (see SHELL=), you can use this command to load TSRs prior to
execution of the application as the shell.
LASTDRIVE = x
Specifies the number of drives owned by DOS. Any device driver loaded which creates a new
drive letter begins at the next drive letter after the drive letter specified in this command.
This command is necessary only if the number of drive letters automatically served by DOS
must be increased. DOS automatically allocates A: and B:, plus C: and possibly D: if ROM
disk(s) are present. The RAM disk driver and Stacker are examples of drivers that allocate
drive letters starting with the next available drive letter. One common use of this command
is to ensure that the RAM disk driver and Stacker use the same drive letters, regardless of how
many ROM disks are loaded (e.g., LASTDRIVE = D: causes the first installable drive letter
to be E:, regardless of whether C: and D: are present or not).
Another possible use of this command is to reserve one or more drive letters for use by the
DOS SUBST command.