Back to home page

DOS ain't dead

Forum index page

Log in | Register

Back to the forum
Board view  Mix view

Phil Gardner's Wrapper.sys & MS-DOS7 bug (Miscellaneous)

posted by Ninho(R) E-mail, 12.12.2009, 11:50
(edited by Ninho on 12.12.2009, 16:10)

>> The problem is completely, and safely, solved by flipping ONE bit of
>> DOS code in conjunction with ONE unused bit of flags in the DOS data
>> area.
>
> It's not unused though, is it?

Not that bit! I take possession of a previously unused bit in the same byte. MS uses bits 0,1,2 only. I deign to leave bit 3 in their realm, and I annex bits 4-7 of which bit 4 shall be used in the present hack.

Let's now if you please all use the new thread for the new FIXWRAP.
I'll explain everything there (though I'm sure you now guess the main lines).
Link to the new technical sub-thread : http://www.bttr-software.de/forum/forum_entry.php?id=7351


> By the way, the test has the same offset in DOS 7.10 but it tests 03h,
> i.e., two bits. I have no idea about DOS 8.0. It seems I never prepared a
> listing. I also don't recall any dependency by Windows on this offset: it
> looks like it's genuinely an internal variable.

In ME also the instruction tests for 03h. But I don't care, I only need to add the test of MY bit (bit 4 it shall be), so I change that instruction to TEST against 13h (or 11h in original Win 95). As I said the installation of the hack will just have to flip the repective bit in the TEST instruction. It could also be made permanently to my/your/their of the IO.SYS file, BTW, without damage but without real advantage since the fix will have to be loaded anyway.

Ah, I am aware of more details than you may think. I have an idea what bit 1 is used for, at least partially - in conjunction with the following byte, they're used during Windows start, the infamous secret handshake that occurrs between Win.COM and Kernel386 IIRC from my old attempts at launching Windows, i.e. the VMM.VXD, without the help of Win.com). We do not care in the least as far as the present project is concerned...

Nuff said - I'll update the other thread only, but I must beg your patience.


Regards...
--
Ninho

Message edited, the earlier version was confused.

 

Complete thread:

Back to the forum
Board view  Mix view
15115 Postings in 1359 Threads, 249 registered users, 26 users online (2 registered, 24 guests)
DOS ain't dead | Admin contact
RSS Feed
powered by my little forum