Ok i have a W98 boot disk. I need to disable the F8 startup menu. This can be done with 6.22 by editing MSDOS.SYS and putting 0 on certain Boot [Options]. This has no effect on W98 disk and actually makes it hang. I thought if i can patch IO.SYS to disable F8. It could even be command.com but i believe it be IO.SYS as that gets loaded after. I looked up the keyboard scan codes and hex 42 00 is coming up on F8. I also looked up what interrupts use the keyboard. INT9 INT21 and INT16 seem to be the ones. I went through the code and 4200 comes up a few times but too many times... Does anyone have a clue on assembler or can help me find the right opcode to patch. Thanks.

It looks like if you add:

BootKeys=0

to the [Options] section of msdos.sys then the F keys will be disabled:

http://www.pchell.com/software/msdo...

The msdos.sys on a bootdisk is pretty much just a placeholder and doesn't have any default options. But you should be able to add an [Options] section and then the bootkey command.

I added:

[Options]
BootKeys=0

to msdos.sys on a bootdisk and that did disable F8. However it would come up with the 'Windows has detected a registry/configuration error. Choose, Command prompt only, and run SCANREG' and then give the bootmenu.

Apparently adding those lines caused msdos.sys to be treated as if it was the windows version and that flagged a default error message. It does continue to bootup OK after choosing one of the menu options. (Of course, having the menu show up is the same as not disabling F8.)

You might try various other msdos.sys commands and see if you can keep that error message from coming up.

This will work:

[Options]
BootGUI=0
BootKeys=0

Just edit your msdos.sys to have only those three lines and it will disable F8 and you won't get the error message. (Apparently the missing 'BootGUI' line was causing the error message.)

Yes it does work but i it was hanging for me long time experimentating. I have now realised why. It's because when i add JO.SYS to the bootable CD floppy image and edit MSDOS.SYS as well it hangs. They don't work together and i don't know why. There must be a possible way to fix this.

It doesn't hang when using a bootdisk. It goes to the cdrom support options menu with no lag and then continues to load with whichever option is chosen. Do you mean you're having this problem when you're using that disk (with the edited msdos.sys) as the system disk when creating a boot cd?

Yes. The system disk is the bootable CD part and it works fine if i add those MSDOS.SYS boot options but i have JO.SYS that gives a brief prompt to load CD. If i add anything to the MSDOS.SYS as well it hangs.

OK, I understand now. When you mentioned jo.sys I thought it was a typo for io.sys and was wondering why you talked of 'adding' it when it was already part of the system files.

This link is about a different situation than yours:

http://support.microsoft.com/kb/187641

But the relevent statement:

"The Jo.sys file can not load the MS-DOS versions of the Msdos.sys file. . ."

indicates an innate problem between jo.sys and msdos.sys.

There's a 'Barts jo.sys'. His links are dead but I found a download here:

http://69.90.47.6/mybootdisks.com/m...

His modifications may get around that problem. Be sure to read the included jo.txt file.

If you want to disable F5/F8 in PCDOS 6, 7 or MS-DOS 6 put this in config.sys

SWITCHES=/n

For MS-DOS 7, 7.1 put this in MSDOS.SYS

[Options]
BootKeys=0

The dream you dream alone is only a dream,
The dream we dream together is reality.

I meant to say W95 not 6.22 in my first post. I have tried the Bart one and MS one and the same result. I have narrowed down the problem. The problem arises by adding:

[Options]
BootKeys=0

Any other option it likes. BootKeys=0 stops loading of the Startup menu which in turn makes the CD prompt hang used by JO.SYS It's as if JO.SYS uses the menu for it to work, even when i try this from a floppy same happens.

Putting SWITCHES=/n in config.sys prevents but when you add JO.SYS it doesn't as it loading up another menu so to speak so it will not prevent.

os2fan2
Get a W98 boot disk edit MSDOS.SYS and add
[Options]
BootKeys=0

and then add any MS or Bart JO.SYS and you see what i mean. It hangs when the press a key at the CD prompt.

I assume you don't have the problem if you don't add jo.sys? But then I guess you wouldn't get the 'boot from cd' option.

Thats right. I have solved it by disabling the keys in IO.SYS. The menu disabled and Jo.sys works fine too. Thanks for your help.

We're glad you got it fixed. It didn't look like going through msdos.sys was going to get it done.