Using HIMEM.SYS and EMM386.EXE DOS memory management software to conserve conventional memory by loading COMMAND.COM and device drivers into extended memory.
Following is an example of a CONFIG.SYS file using HIMEM.SYS and EMM386.EXE memory management.
The extended memory manager, HIMEM.SYS is loaded first, followed by EMM386.EXE. EMM386.EXE has several purposes:
In this case the NOEMS switch has been used to indicate that no extended memory should be used to emulate expanded memory.
The command dos=high,umb will load a portion of dos into the high memory system and make the Upper Memory Blocks available.
The command deviceHigh=c:\windows\command\ansi.sys loads the ANSI.SYS device driver into the UMB area of memory.
device=c:\windows\himem.sys device=c:\windows\emm386.exe noems dos=high,umb deviceHigh=c:\windows\command\ansi.sys files=200 buffers=20
The result of these commands can be seen by issuing the following command from the command line:
mem /c | more
This will give the following screen output. In this case note the areas of memory being used by System and ANSI.SYS.
Name Total Conventional Upper Memory -------- ---------------- ---------------- ---------------- SYSTEM 40,336 (39K) 10,976 (11K) 29,360 (29K) HIMEM 1,104 (1K) 1,104 (1K) 0 (0K) EMM386 4,320 (4K) 4,320 (4K) 0 (0K) DBLBUFF 2,976 (3K) 2,976 (3K) 0 (0K) WIN 4,016 (4K) 4,016 (4K) 0 (0K) vmm32 52,672 (51K) 640 (1K) 52,032 (51K) DOSKEY 4,688 (5K) 4,688 (5K) 0 (0K) COMMAND 7,888 (8K) 7,888 (8K) 0 (0K) ANSI 4,320 (4K) 0 (0K) 4,320 (4K) IFSHLP 2,864 (3K) 0 (0K) 2,864 (3K) Free 618,192 (604K) 618,192 (604K) 0 (0K)
Type of Memory Total Used Free ---------------- ----------- ----------- ----------- Conventional 655,360 37,168 618,192 Upper 88,576 88,576 0 Reserved 393,216 393,216 0 Extended (XMS) 65,971,712 ? 266,424,320 ---------------- ----------- ----------- ----------- Total memory 67,108,864 ? 267,042,512 Total under 1 MB 743,936 125,744 618,192 Largest executable program size 618,176 (604K) Largest free upper memory block 0 (0K) MS-DOS is resident in the high memory area.