Symbol PDT 3400 Series, Руководство по продукции

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7-2
PDT 3400 Product Reference Guide
A protected RAM Disk survives a warm reboot, keeping all files stored on the disk intact.
RAM Disk can be preserved following a cold reboot IF power was not removed for more
than 15 minutes AND the EMSALLOC.SYS driver was not used to increase the RAM Disk
size (see section Using EMSALLOC.SYS to Increase Size of RAM Disk for more
information). Additionally, the Symbol RAM Disk driver takes precautions to protect the
data stored on a protected RAM disk from accidental corruption.
By default, RAM disks created by RDISK34T.SYS are protected. To create a RAM Disk that
is not protected, use the /NOPROTECT switch on the command line.
Include the /CLEARONCOLD switch on the command line to specify that the RAM Disk is
not to be preserved across cold reboots, even if power to memory is retained.
Using EMSALLOC.SYS to Increase Size of RAM Disk
By default, all RAM up to 640K is allocated to MS-DOS. Any additional RAM, less16K that
is used as Video RAM, is allocated as EMS memory. The RAM allocation on a PDT 3400
with 2 MB of RAM is as follows:
MS-DOS 640 KB
EMS Memory 1392 KB
Video Memory 16 KB
Total 2048 KB (2 MB)
The RAM allocation on a PDT 3400 with 4 MB of RAM is as follows:
MS-DOS 640 KB
EMS Memory 3440 KB
Video Memory 16 KB
Total 4096 KB (4 MB)
To allow more flexibility in allocating RAM memory, Symbol supplies an EMS Allocation
utility, EMSALLOC.SYS. This utility allows you to allocate less memory to MS-DOS, leaving
additional memory available for use as EMS memory. The RAM allocation for MS-DOS can
be adjusted from the default 640 KB down to a minimum of 256 KB. This adjustment can
result in a RAM allocation for EMS memory of up to 1446 KB on a PDT 3400 with 2 MB
of RAM, or up to 3824 KB on a PDT 3400 with 4 MB of RAM.