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

posted by Ninho(R) E-mail, 18.11.2009, 20:41

Hi, Dinos! Anybody remembers Phil Gardner's excellent wrapper that enabled (quoting the DOC file)

... the loading of programs in
the CONFIG.SYS file as devices. The program may be a Terminate-and-
Stay Resident utility (TSR) or a program which simply executes but does
not stay resident.

(quoting ends.)

Excellent program (used to be try-before-buy shareware). Unfortunately it mostly stopped working starting with MS-DOS 7 (Win 9x). I remember studying the problem in the late 90s and came to the conclusion that MS DOS 7 introduced a bug whereby int 21 AH=31 (or int 27h which is the same code) when attempted during config.sys DEVICE installation trashes essential DOS memory because an uninitialised pointer (still = 0:0) is used erroneously.

I long thought I was the only one on earth to be aware of the bug (smile) - but of course others found and analysed it better than I ever did (yesterday while browing I found a Geoff Chappel page (spell?) about the bug in question and how he worked around it in his own programs).

Of course not having the wrapper.sys source makes the task very difficult of implementing a similar work around. This is the kind of things I might have attempted when younger... oh the joys of getting old.

Well, this makes me ask : does anyone have a version of wrapper.sys hacked around the MS-DOS 7+ bug ? Or have written an original new 'wrapper' with functionality equivalent to Phil's ? When I sought a few months ago I found Mr Gardner is now some kind of executive, or is he a president, at some Canadian software company, probably not interested in his old DOS shareware any more, in any case an email I sent to his company contact remained unanswered, either lost or trashed. :=(

Sorry for the rambling. Thought I'd ask the question here.


Note : Only DOS programs that terminate and stay resident are affected by the M$ bug. Ordinary, transient DOS programs can still be launched by Wrapper.

---
Ninho

 

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