Avery Dennison 6035 Programmer Manual Rev.A 7/98 - Manual (Page 45)

7/9/98 Using ROM-DOS 6.22 2-33
H I M E M
Overview
Manages extended memory and the High Memory Area (HMA) in a 286,
386, or greater or PS/2 system. HIMEM prevents programs from
simultaneously using the same area of memory for two different
purposes. HIMEM supports the eXtended Memory Specification (XMS)
2.0. HIMEM is installed as a device driver in CONFIG.SYS.
Syntax
device = [d:] [path] HIMEM.SYS [/machine:n] [/A20[+]] [/PS2]
Remarks
HIMEM can be used to allow ROM-DOS to run in High Memory.
HIMEM supports a default of 32 handles.
HIMEM should not be used with older versions of Datalight VDISK.
Current versions of VDISK uses XMS memory if it is available.
HIMEM now recognizes PS/2 style machines A20 line control. HIMEM
determines whether to use the PS/2 A20 control or the AT A20 control
method automatically by calling Int 15h, function C0h (get system
configuration).
The automatic detection can be overridden with the “/Machine:n”, /A20
/A20+, or /PS2 command line switch if the autodetection on a given
system is failing.
/Machine:1 and /A20 are equivalent and designate the PC AT A20
control method. These switches instruct HIMEM not to wait for the A20
line to settle.
/Machine:2 and /PS2 are equivalent and designate the PS/2 control
method.
/A20+ is similar to the standard /A20 option; however it instructs
HIMEM to wait for the A20 line to settle.