The package for A20 Line Always On processing (and more) in HIMEM.SYS

[SweetLow]

On 6/20/2026 at 1:04 AM, cov3rt said:

i always get the unable to control A20 line

It is normal for hardware with Always On A20 line, I assume it is obvious.

[cov3rt]

On 6/21/2026 at 11:50 AM, SweetLow said:

It is normal for hardware with Always On A20 line, I assume it is obvious.

ok but also XMS driver could not be loaded / command.com, etc. is that normal too?

btw, this isn't same topic but i was wondering if you know whether "patcher9x" package includes all fixes from rloew's patchmem, or does one need to install patchmem before patcher9x in certain situations. patcher9x notes does reference certain portions of adding patchmem, but im not sure if that means everything from it - https://github.com/JHRobotics/patcher9x

Edited Monday at 10:05 PM by cov3rt

[SweetLow]

10 hours ago, cov3rt said:

but also XMS driver could not be loaded

If you said about error in some software you had to describe exactly error in software, not behaviour of hardware.

If you have error in himem.sys then take patched version (one of the two "preferred", of course) and just replace %windir%\HIMEM.SYS (or anywhere you want).

>if you know whether "patcher9x" package includes all fixes from rloew's patchmem

not all fixes, but all essential

Edited Tuesday at 08:58 AM by SweetLow

[cov3rt]

i thought i gave enough information. i dont know what else to do that would be feasible for me, but let me post some more info. 

as i was discussing back to chatgpt. they specifically mentioned to remove "umb" from the config.sys

for the 98SE boot disk iso burned to cd, booted it on hp probook 6460b - selected - start computer with cd rom support, then:

error - unable to control a20 line! xms driver not installed.  loads a couple cd dos drivers, 
then ram drive - extended memory manager not present. warning - the high memory area (hma) is not available. 
additional low memory (below 640 KB) will be used instead. windows 98 startup disk could not create a temporary 
driver for the diagnostic tools. this may be because this computer has less than the minimum required extended 
memory. path not found - :\command.com, :\extract.exe, :\readme.txt, bad command or file name, the diagnostic 
tools were successfully loaded to drive . file not found.

-------------------------------------------------------------------------------------------------------------------------------------------

i tried various combinations below in config.sys

DEVICE=HIMEMX2.EXE /MAX=256M /METHOD:ALWAYSON /VERBOSE - didn't work with "umb" omitted from config.sys

or

device=HIMEMX2.EXE /MAX=256M /METHOD:PORT92 /VERBOSE - didn't work with "umb" omitted from config.sys

or 

device=HIMEMX2.EXE /MAX=256M /METHOD:BIOS /VERBOSE - didn't work with "umb" omitted from config.sys

an example file of config.sys i used:

[menu]
menuitem=CD, Start computer with CD-ROM support.
menuitem=NOCD, Start computer without CD-ROM support.
menuitem=HELP, View the Help file.
menudefault=CD,30
menucolor=7,0

[CD]
device=HIMEMX2.EXE /MAX=256M /METHOD:BIOS /VERBOSE
device=oakcdrom.sys /D:mscd001 
device=btdosm.sys 
device=flashpt.sys
device=btcdrom.sys /D:mscd001
device=aspi2dos.sys
device=aspi8dos.sys
device=aspi4dos.sys
device=aspi8u2.sys
device=aspicd.sys /D:mscd001

[NOCD]
device=HIMEMX2.EXE /MAX=256M /METHOD:BIOS /VERBOSE

[HELP]
device=HIMEMX2.EXE /MAX=256M /METHOD:BIOS /VERBOSE

[COMMON]
files=40
buffers=40
dos=high
stacks=9,256
device=ramdrive.sys /E 2048
lastdrive=z

------------------------------------------------------------------------------------------------------------

i also used xmgr.sys with the following in config.sys:

[menu]
menuitem=CD, Start computer with CD-ROM support.
menuitem=NOCD, Start computer without CD-ROM support.
menuitem=HELP, View the Help file.
menudefault=CD,30
menucolor=7,0

[CD]
device=XMGR.SYS /R
device=oakcdrom.sys /D:mscd001 
device=btdosm.sys 
device=flashpt.sys
device=btcdrom.sys /D:mscd001
device=aspi2dos.sys
device=aspi8dos.sys
device=aspi4dos.sys
device=aspi8u2.sys
device=aspicd.sys /D:mscd001

[NOCD]
device=XMGR.SYS /R

[HELP]
device=XMGR.SYS /R

[COMMON]
files=40
buffers=40
dos=high
stacks=9,256
device=ramdrive.sys /E 2048
lastdrive=z

------------------------------------------------------------------------------------------------------------------------

Edited Tuesday at 08:10 PM by cov3rt

[SweetLow]

10 hours ago, cov3rt said:

for the 98SE boot disk iso burned to cd, booted it on hp probook 6460b - selected - start computer with cd rom support, then:

error - unable to control a20 line! xms driver not installed

Of course you will get error. You try to use unpatched himem.sys ->

21 hours ago, SweetLow said:

just replace %windir%\HIMEM.SYS (or anywhere you want).

Unpatched himem.sys locates on boot floppy image of Windows 98 Install CD. Replace it there by patched version.

[cov3rt]

No, i used various combinations in your "a20alwon" package, all of them produced the same messages i mentioned earlier. these were all with usb legacy checked in bios, and fast boot = off. i also re-tested your "2_1_PREFERRED" method with usb legacy unchecked, but no change.

To isolate this better, can you perhaps upload an already made modified ms dos 7.1 boot disk iso for me to test so i can check whether i'm doing something wrong or not? I attached my original 98SE boot disk below ( expires in 1 week ). 

https://limewire.com/d/ow9JG#U7khgdkRPI

Edited Wednesday at 11:55 PM by cov3rt

[SweetLow]

6 hours ago, cov3rt said:

i used

Used where? You described only problem with install Windows 98 from CD. No mentions of attempt to boot from USB Drive for example.

 

6 hours ago, cov3rt said:

my original 98SE boot disk below

Do you understand what is boot floppy image and what its purpose in CD-ROM boot process? Your .ISO has UNTOUCHED floppy image. I assume it's time to read something, El Torito standard for example and to study some .ISO authoring/editing software.

Edited yesterday at 06:12 AM by SweetLow

[cov3rt]

I burned the 98SE boot disk iso onto a cd and booted it via internal optical drive ( sata in ide mode ) on the Hp probook 6460b. I have used this method on other computers without problem, of course, almost all of them were much older ( usually no newer than ich6 ) and usually the connection was pure ide, not sata in ide mode. 

 

 

 

[cov3rt]

I was able to figure out the main issue after chatgpt referenced boot image related stuff. essentially it was not using the actual modified stuff, because i wasn't providing the .img/.ima base file from beforehand when creating the boot media via the software i was using. i know you did mention about this earlier, but i didn't understand what that meant exactly in my context. for those starting with just the 98SE boot disk iso, you'll need winimage + ultraiso and / or anyburn, but if you already have a stock 98SE boot image in .img form, then all you need is ultraiso i believe.

i had chatgpt write a short guide on this, but i'm also providing the boot disk in .ima form already + my modified 98SE boot disk iso already made as attachments for some time so people can download and use / test, though i haven't been able to test the iso one's actual functionality, because i only have unsupported systems at the moment that are incompatible, like "hp 14-dq0054dx" using an external usb optical drive, shows as no fixed drive present, AHCI not loaded, etc. the boot disk doesn't support NTFS. It is essentially stock 98SE boot disk + CTMOUSE, AHCICDA.SYS, HimemX2, JEMM386.EXE, UIDE.SYS, modified autoexec.bat/config.sys/setramd.bat. 

https://limewire.com/d/Dq2t6#JQjSz1GzN9

SHORT VERSION for creating bootable el torito cd iso using extracted modified files injected into ultraiso 
+ stock 98SE boot disk .ima file:

CLEAN SHORT METHOD (what you want)

You already have:
- Stock Win98SE boot .IMG (good boot sector)
- Modified boot files (CONFIG.SYS / AUTOEXEC.BAT / drivers)
- ISO content (WIN98 folder / CAB files etc.)

STEP 1:
Open the .IMG in WinImage and make sure your modified CONFIG.SYS and AUTOEXEC.BAT are inside it.
Save the .IMG.

STEP 2:
Open UltraISO.

STEP 3:
File -> New -> Data CD/DVD Image

STEP 4:
Drag and drop the Windows 98 CD files into the ISO project:
- WIN98 folder
- CAB files
- SETUP.EXE (if present)

STEP 5:
Bootable -> Load Boot File
Select your modified Win98SE boot .IMG

STEP 6:
File -> Save As
Choose: Standard ISO (*.iso)

 

Edited 1 hour ago by cov3rt