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alternative config.sys

Posted: Fri May 06, 2011 2:49 am
by ady
I have a situation I need to describe so to post the real question and goal here. The final goal: having the possibility of customize the config.sys / autoexec.bat entries of FDUBCD.

I'll describe now the situation and the possibilities I already thought about. (please, be patient :oops: )

I have a DOS bootable floppy image that is used to boot and run a partition/cloning tool. I want to customize ubcd to include this program.

The floppy image is based on FreeDOS, so it uses the same basic files that fdubcd.img uses. Some of those files are ctmouse.exe, shsucdx.com, xcdrom.sys...

In theory, I could simply put the main executable in the "custom" directory of fdubcd.IMG, but the floppy image uses a specific config.sys and autoexec.bat (or their respective FreeDOS equivalents) that are different from the possibilities/options currently available in fdubcd.IMG.

A first (very simple) possibility for this type of customization would be to add the complete 1440KiB floppy image, and use it independently from fdubcd.img. Having all the necessary files already included in fdubcd.IMG (except for the program executable itself), I'd like to find an alternative possibility.

The next (2nd) possibility I thought about is to press <F8> during the boot selection options of fdubcd so to select (yes/no) each of the commands from the DOS boot process that I want to run. The problem is that the current commands are not exactly the same commands included in the specific config.sys and autoexec.bat I have.

For example, if the config.sys in fdubcd.IMG have a command like:

Code: Select all

device=\bin\himem.exe /MAX=64000
and I would need a different "himem.exe" command, then the "yes/no" selection is not enough. Please note that this command is only an example, so please do not focus on the specific command.

The third possibility I thought about is to customize the current config.sys and autoexec.bat with an additional "MENU" option. This is not so complicated, if you know what you are doing :).

My only concern here would be some incompatibility with some other part of fdubcd.ISO, by adding an additional "menu" option in config.sys. Now the numbers that respond to a specific option could change, or the total number of options would change.

In addition, this possibility could only help with one (maybe with 2) specific programs. In case I want/need to add specific config.sys / autoexec.bat entries, I would be limited by the number of options, or by making the config.sys file too complicated. "Complication" is fine, if you need to do the job once, but for any future change in next releases of ubcd, I'd need to check/test any config.sys customizations again, possibly introducing more problems than solutions.

This 3rd possibility (customized config.sys) can be even more complicated if I would add "submenu" options (which could potentially solve the "number of options" limit).

The 4th possibility I thought about is having an "alternative" config.sys to run. The difference between this possibility and the 1st one (entire DOS floppy image) is that we only would need this "alternative config.sys" (in addition to the executable) in some CAB or IMG.GZ file, instead of the complete set of FreeDOS files again.

My only problem with this possibility is that I have no idea how to have a config.sys file different from the default already included in fdubcd.IMG, but still use fdubcd.img with all the files inside it :?: .

This possibility would need fdubcd.img to be decompressed/expanded, but the booting process would need to read the alternative config.sys file to know what to do, instead of using the normal default config.sys.

In almost any case, I still would have to deal with autoexec.bat, but that is less problematic because I can add additional commands in "startup.bat" to solve most (but not all) the needed commands. So the special / alternative config.sys issue is far more problematic than the specific autoexec.bat.

If any of these alternative possibilities makes sense (besides the first obvious one of adding the complete floppy with all the files duplicated), maybe we can develop a method to add DOS-based executables that need special booting options (special config.sys), without having to tamper with the default config.sys in fdubcd.img too much :?: :!: .

Any ideas? I am specially interested in having the possibility of expanding fdubcd.img so to boot with an alternative config.sys.

TIA.

PS: Apologies for the long post.

Re: alternative config.sys

Posted: Tue May 10, 2011 9:57 pm
by Victor Chew
For 1) 2) and 3), I think you'd be better off creating your own version of fdubcd.img.

I understand what you are trying to do with 4), but I don't think DOS has a way of supporting alternate CONFIG.SYS.