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Chapter 4
Memory Configurations
This chapter explains the different memory configurations of the BC 4000 486 product. The default configuration on the board is 640K of conventional DOS memory, 256K of Expanded (EMS) memory, and 1024K of Extended memory. You can add additional memory up to 16 MB, and configure it through the setup program as Expanded or Extended memory.
The 256K block of memory between Video and ROM BIOS memory (Figure 5-1) can be used as expanded memory. It cannot be converted to, or used as extended memory. Any additional memory added above 1MB (up to 16Mb total) can be used as either Expanded or Extended memory.
Expanded (EMS) Memory Driver
To access expanded memory from most application programs, you must first install an expanded memory driver. The driver (MMTOPCAT.SYS) is needed for the TOPCAT chip set used on this board. The driver is available on the Cubix Customer Service BBS.
To install the expanded memory driver:
1. Copy the MMTOPCAT.SYS file to the floppy boot diskette, or root subdirectory on the hard drive.
2. Add the following line to the CONFIG.SYS file on the boot diskette for the board. DEVICE = MMTOPCAT.SYS
3. Reset the board. Your application program will now be able to access the expanded memory.
Adding Additional Expanded Memory
You can add up to 14MB of additional Expanded memory to the board with SIMMs. Accessing this additional memory follows the same rules as above. See the <BI>BC 4000 Hardware Chapter<D> for information on installing additional memory SIMMs.
Expanded Memory Driver Technical Information
The EMS Memory driver (MMTOPCAT.SYS) conforms to LIM 4.0. Version 4.0 of the LIM specification is upward compatible with version 3.20 and will run programs written for that version of the driver.
MMTOPCAT.SYS Optional Parameters
/USESHADOW
Specifies the shadow memory not currently being used to copy ROM's into RAM may be used as EMS memory. /HANDLES=nnn This parameter specifies the number of handles that will be available for programs which use EMS memory. The default number is 255. This is the maximum number allowed by the LIM EMS specification. The minimum number of handles that can be allocated is 3.
/CONTEXTS=nn
This parameter specifies the number of contexts which can be saved by processes using EMS memory. The default number of contexts is equal to the number of handles that are allocated. The maximum number of contexts is 255. The minimum number is 3.
/DEPTH=nn
This parameter specifies the number of consecutive contexts that can be saved for a given handle before a restore must be initiated. The default depth is 5, but can be set to any value from 1 to 32.
The memory above 1MB on the BC 4000 board is usable as extended memory. The memory below 1MB on the boards cannot be converted to, or be used as extended memory.
Extended Memory Driver
If your application program requires an extended memory driver, you must add it to the boards CONFIG.SYS file. The extended memory driver is not provided by Cubix. It is provided with Microsoft Windows, and DOS 5.0. If you do not have these programs, you can obtain the driver from CompuServe, the Cubix BBS, or most local BBS's. The extended memory driver is called HIMEM.SYS.
Installing the Extended Memory Driver
1. With an ASCII editor, modify the CONFIG.SYS file on the boot diskette, or root directory of the hard disk. Add the following line to the file:
DEVICE=HIMEM.SYS
2. Copy the HIMEM.SYS file to the diskette or hard disk.
3. Reset the BC 4000 board.
The BC 4000 board installed in a subsystem becomes a 486 computer, complete with diskette drive, monitor and keyboard. You can run any DOS version on the processor that you would on any workstation on your network. There are no restrictions on DOS versions, Memory Manager programs, or software applications other than the restrictions you would encounter on any 486 LAN workstation.
DOS Versions
Currently, there are only two versions of DOS that have built-in memory management programs. These are Microsoft's DOS 5.0, and DR-DOS 6.0 from Digital Research. Any other version of DOS requires a third party memory manager program. Cubix does not provide any memory manager programs for this product. To get the most efficient use of memory on this product, we suggest using one of the two versions of DOS listed above. There are also third party software programs that work with these two versions of DOS to further increase the memory options.
These products will work on the BC 4000 board in the same manner as any 486 workstation on your LAN.
Since memory management is such a critical part of any LAN workstation configuration, we have included some tips and suggestions that may help you.
Configuration 1
DOS 5.0 - BC 4000 board with 2MB Memory, with a Western Digital Ethernet board at: IRQ =3, I/O Base=280, RAM =C800: for 16K
CONFIG.SYS
DEVICE=HIMEM.SYS
* DEVICE=EMM386.EXE I=CC00-F000 X=C800-CBFF NOEMS (EGA)
* DEVICE=EMM386.EXE I=A000-B800 I=CC00-F000 X=C800-CBFF NOEMS (CGA)
* DEVICE=EMM386.EXE I=A000-B000 I=CC00-F000 X=C800-CBFF NOEMS (MONO)
DOS=HIGH,UMB
FILES=10
LASTDRIVE=E
* = Only add one of these three lines, depending on the video option (see note 1 below).
AUTOEXEC.BAT
PROMPT P$G
LH IPX
LH NETX
F:
LOGIN
Configuration 2
DOS 5.0 - BC 4000 board with 2MB Memory, with a Novell NE2000 Ethernet board at: IRQ =3, I/O Base=300, no DMA or RAM
CONFIG.SYS
DEVICE=HIMEM.SYS
* DEVICE=EMM386.EXE I=C800-F000 NOEMS (EGA)
* DEVICE=EMM386.EXE I=A000-B800 I=C800-F000 NOEMS (CGA)
* DEVICE=EMM386.EXE I=A000-B000 I=C800-F000 NOEMS (MONO) DOS=HIGH,UMB
FILES=10
LASTDRIVE=E
* = Only add one of these three lines, depending on the video option. (see note 1 below).
AUTOEXEC.BAT
PROMPT P$G
LH IPX
LH NETX
F:
LOGIN
Configuration 3
DOS 5.0 - BC 4000 board with 2MB Memory, with an IBM Token Ring Adapter set at: IRQ =2, ROM:C800-CA00, Shared RAM=16K, Shared RAM at CC00 (set with IPX command line option, IPX o,mem=CC00 ).
CONFIG.SYS
DEVICE=HIMEM.SYS
* DEVICE=EMM386.EXE I=D000-EFFF X=C800-CFFF NOEMS (EGA)
* DEVICE=EMM386.EXE I=A000-B800 I=D000-EFFF X=C800-CFFF NOEMS (CGA)
* DEVICE=EMM386.EXE I=A000-B000 I=D000-EFFF X=C800-CFFF NOEMS (MONO)
DOS=HIGH,UMB
FILES=10
LASTDRIVE=E
* = Only add one of these three lines, depending on the video option. (See note 1 below.)
AUTOEXEC.BAT
PROMPT P$G
LH IPX O,MEM=CC00
LH NETX
F:
LOGIN
@NOTE = Selecting CGA or MONO will increase the DOS memory, but you can only use video up to the option you select. For example, if you select monochrome, you can only run monochrome applications, no graphics.
This document, and all Web contents, Copyright © 1997
by Cubix Corp., Carson City, NV, USA.
