Workstation Memory Configurations with
MS-DOS
See also IPB 1053
There is no single default memory configuration recommendation for all
Apricot systems due to differing software environments and system-specific physical
restrictions. We hope, however, that the following general information will be useful for
most workstations.
The following are addressed:
General Issues
Current Products
EPx
XEN-PC, XEN-PCm
XEN-LS II
LS Pro
Earlier Products
LS 386SX, XEN-LS & XEN-S
Qi 386SX, Qi 386 & Qi 486
Systems with 1MB RAM
General Issues
Unless specifically required, remove the following drivers and TSRs from
CONFIG.SYS and AUTOEXEC.BAT:
DEVICE=APRA20.SYS (required for Qi 386-25 / Qi 600 series ONLY)
DEVICE=SETVER.SYS
DEVICE=SMARTDRV.EXE /DOUBLE_BUFFER
DEVICE=DISPLAY.SYS
MODE CON CODEPAGE...
EPx
Upper memory area available: C800h-E7FFh
EMM386 may be used to access this upper memory as follows:
First entries of CONFIG.SYS
EVICE=C:\DOS\HIMEM.SYS
EVICE=C:\DOS\EMM386.EXE X=C000-C7FF I=C800-E7FF X=E800-EFFF NOEMS
OS=HIGH,UMB
If add-in cards are installed, it will be necessary to incorporate RAM
space used by the cards (if any) into the exclusion parameters of the EMM386 line in
CONFIG.SYS. For example, if a network card is added with 16KB of adapter RAM, configure
the card so that the adapter RAM starts at E400h (the highest available 16KB block in
upper memory) and change the EMM386 line to:
DEVICE=C:\DOS\EMM386.EXE X=C000-C7FF I=C800-E3FF X=E400-EFFF NOEMS
If expanded memory (EMS) is required, the NOEMS parameter should be
substituted with something like FRAME=C800 256 RAM, where C800 is the first available
hexadecimal address for the start of the 64KB EMS page frame and 256 is the size expanded
memory required in KB, as follows:
DEVICE=C:\DOS\EMM386.EXE X=C000-C7FF I=C800-E7FF X=E800-EFFF FRAME=C800
256 RAM
The size of EMS may be increased, as required, to the maximum XMS memory
available.
XEN-PC & XEN-PCm
Upper memory area available: C800h-EFFFh
The upper memory area may be accessed in the same way as the EPx example
above, although the EMM386 line will need to read as follows:
DEVICE=C:\DOS\EMM386.EXE X=C000-C7FF I=C800-EFFF NOEMS
Expanded memory and add-in card issues are the same as for the EPx
detailed above.
XEN-LS II
Upper memory area available: C800h-EFFFh
The upper memory area may be accessed in the same way as the EPx example
above, although the EMM386 line will need to read as follows:
DEVICE=C:\DOS\EMM386.EXE X=C000-C7FF I=C800-EFFF NOEMS
If preferred, APRUMB.SYS (version 1.10 at the time of writing), may be
used to access upper memory as follows:
config.sys
DEVICE=C:\DOS\HIMEM.SYS
DEVICE=C:\DOS\APRUMB.SYS
DOS=HIGH,UMB
This will give access to 160KB of upper memory and makes better overall
use of system resources.
Expanded memory and add-in card issues are the same as for the EPx
detailed above.
LS Pro
BIOS release 2.0 or greater - Upper memory
area available: C800h-EFFFh
The upper memory may be accessed in the same way as the XEN-LS II.
BIOS release 1.XX - Upper memory area
available: C000h-EFFFh.
The full upper memory area from C000h to EFFFh is available on the LS
Pro, provided the BIOS version is 1.05 or greater; earlier releases of the BIOS reserved
the area E000h-E3FFh for remote booting code. EMM386 may be used to access the upper
memory as follows:
DEVICE=C:\DOS\EMM386.EXE I=C000-EFFF NOEMS
If the BIOS is 1.04 or less, the EMM386 line should read:
DEVICE=C:\DOS\EMM386.EXE I=C000-DFFF X=E000-E3FF I=E400-EFFF NOEMS
Expanded memory may be configured as in the EPx example above.
If preferred, APRUMB.SYS may be used to access the upper memory in the
same way as the XEN-LS II example above. This gives access to 192KB of upper memory and
makes better overall use of system resources.
LS 386SX, XEN-LS & XEN-S
Upper memory area available: C000h-EFFFh
Use the SETUP program to confirm that the BIOS speed is set to FAST. The
full upper memory area is available on each of these systems. Both EMM386.EXE and/or
APRUMB.SYS may be used, as described in the LS Pro example above. If expanded memory is
required or if add-in cards have been installed (XEN-LS and XEN-S only) then the same
rules apply as for the EPx example above.
Qi 386SX-16, Qi 386-25 & Qi 486 (Qi 300, Qi 600 & Qi 900
ranges)
Upper memory area available: C000h-DFFFh
Use the REFERENCE disk to confirm that the ROM BIOS shadowing is
enabled. For Qi 386-25 and Qi 486 systems it is also necessary to set SPLIT RAM to
shadowed. Both EMM386.EXE and/or APRUMB.SYS may be used, as described in the LS Pro
example above. If expanded memory is required or if add-in cards have been installed
(XEN-LS and XEN-S only) then the same rules apply as for the EPx example above.
If network drivers are also to be loaded, please refer to IPB 1045 for information on how to prevent DMA clashes when using
EMM386.EXE.
Systems with 1MB RAM
In order to maximise conventional memory, it is customary to enable
upper memory blocks (UMBs) and load DOS into the high memory area (HMA). The latter is
only possible if extended memory (XMS) is present. On a 1MB system, this can only be done
by disabling ROM BIOS shadowing which results in the 384KB of memory above conventional
memory being mapped as extended memory.
Upper memory area available: C000h-EFFFh
Use the SETUP program to confirm that the BIOS speed is set to NORMAL,
or use the reference disk to disable BIOS shadowing if it is an MCA system. EMM386.EXE may
then be configured as described in the LS Pro example above. If add-in cards have been
installed then the same rules apply as for the EPx example above.
EMM386.EXE may only be loaded if the systems has a 386 CPU or higher.
For systems with a 286 processor, APRUMB.SYS and DOS 5.0 or greater may be used.
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