Symbol PDT 7200 Series Product Reference Manual page 75

PDT 7200 Series Product Reference Guide
Extended memory is "translated" into other types of memory such as Upper Memory Blocks
(UMBs) and Expanded Memory (EMS). UMBs allow additional RAM memory to be located
in unused areas of the first 1 MB of the address space. TSRs and drivers can be loaded
into UMBs via the LOADHIGH and DEVICEHIGH commands, leaving additional Transient
Program Area (TPA) available for application use. Expanded memory uses a 64K page
frame within the first 1MB of the address space to allow RAM to be mapped in 16K pages
via the EMS (LIM 4.0) API.
Note: Include EMM386.EXE in the PDT 7200 configuration ONLY if UMBs
or EMS are required.
Recommended command line switches include:
1. If EMS memory is not required, add the following line to allocate all unused Upper
Memory Blocks for DEVICEHIGH and LOADHIGH commands:
DEVICE=EMM386.EXE NOEMS X=C000-CFFF RAM=A000-AFFF RAM=D000-DFFF
CONFIG.SYS DOS Settings
• BREAK = [ ON | OFF ]
Controls whether or not extended CTRL+C checking is enabled. Since this feature
introduces additional overhead and is useful only when a keyboard is attached, it should be
disabled under most circumstances. Off is the default setting; hence this command need
not be used unless this feature is being enabled.
• BUFFERS = n[,m] 1 ≤ n ≤ 99 0 ≤ m ≤ 8
Specifies the number of disk buffers to be allocated for use by DOS. The default value for
the PDT 7200 is n=15 and m=0. Many applications and environments request a larger
setting. Windows, for example, recommends a setting of n=20 and m=0. Using too large a
value wastes memory and using too small a value can reduce performance. Unless there
is a specific requirement, we recommend using the n=20 and m=0 settings.
• COUNTRY = XXX[,YYY]
Specifies the country-specific settings. The default is U.S. This command is required only
for a different country setting.
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