128 ROM-DOS
Commands
MX1 I-Safe Reference Guide
E-EQ-MX1ISRG-F
Note also that some older programs assume that the machine is a 1MB 8086 and so require that
the A20 line to be disabled (OFF) while they run. Current programs typically do not require that
the A20 line be disabled.
Examples
Device = HIMEM.SYS
Installs the XMS device driver. Once this driver is installed, accessing the HMA and Extended
Memory (XMS) memory areas are legal. The Extended Memory area can contain up to 2GB of
memory. Typical systems have 4, 8, or 16MB of XMS memory installed.
Device = HIMEM.SYS /machine:1
Forces the use of the AT-style A20 line control.
The HIMEM driver fails to load when either the machine does not have memory above the 1MB
boundary or the BIOS does not provide support for it. It also fails to load when another XMS
manager has been previously installed.
MEM.EXE
External Command
The MEM command displays the used and free memory in your system.
Syntax
MEM [/BiosExtensions] [/Classify] [/Raw]
Remarks
/B
Displays each BIOS extension and its size.
/C
Classifies the memory usage.
/R
Does raw dump of the MCB chain.
MEM displays a list of the DOS memory contents, what free space is available, and how much
memory is in conventional memory, upper memory, the HMA and extended memory. This
program is useful to fine tune the system to have as much free memory as possible for
applications.
Options
The
/B
option displays BIOS extensions in the range from C000:0 to F800:0.
The
/C
option shows program, TSR, and device driver sizes.
The
/R
option shows a low-level DOS listing of MCBs (Memory Control Blocks).
Summary of Contents for MX1-IS
Page 38: ...28 Miscellaneous Connectors MX1 I Safe Reference Guide E EQ MX1ISRG F...
Page 42: ...32 Handling Batteries Safely MX1 I Safe Reference Guide E EQ MX1ISRG F...
Page 124: ...114 Numeric Alpha Key Map 41 Key MX1 I Safe Reference Guide E EQ MX1ISRG F...
Page 156: ...146 ROM DOS 6 22 Command Summary MX1 I Safe Reference Guide E EQ MX1ISRG F...
Page 164: ...154 Index MX1 I Safe Reference Guide E EQ MX1ISRG F...