From: "Matthias Paul" Organization: IBH, RWTH-Aachen To: opendos-developer AT delorie DOT com Date: Thu, 17 Apr 1997 20:20:52 GMT+0100 Subject: Re: Usage of directory entries Reply-to: Matthias DOT Paul AT post DOT rwth-aachen DOT de Message-ID: <1404FA328C0@ibh.rwth-aachen.de> Precedence: bulk On Thu, 17 Apr 1997, Mark Habersack wrote: > > There is also some weird way that DBLSPACE/DRVSPACE have some weird scheme > > working as an installable filesystem, I don't really know how stacker does > > it (although I assume it's similar) > They use some tricks to inject their code into the system (remember the > DRVSPACE.BIN file?) and work as a replacement for the FS/DEVICE FAT > routines built into the kernel. Stacker probably uses the > DRIVER.SYS approach (I'm not sure). STACKER (at least since 3.10+) also uses the so called pre-load API in IBMBIO.COM (before execution of CONFIG.SYS). This has been a major law act at that time, when Stac sued Microsoft for using Stac patented algorithms in DBLSPACE without licensing them, and Microsoft was forced to stop shipping MS-DOS 6.20 (including DBLSPACE) and replace it by MS-DOS 6.21 (without DBLSPACE). However, Microsoft had a longer breath and sued Stac for de-assembling the undocumented pre-load API in MS-DOS 6.20+ (needed to let STACKER install the same way as DBLSPACE could). Since Stac suffered from M$ pressure and was almost running out of money, they made a deal with M$: Stac was 'allowed' to use the pre-load API (as also de-assembled by many other vendors without being sued for), and M$ could ship DRVSPACE with MS-DOS 6.22... Matthias ------------------------------------------------------------------ Matthias Paul ! My eMail address has changed. For some time ! Ubierstrasse 28 ! mails to former ! D-50321 BRUEHL ! will be forwarded to the new address. ! eMail: WWW : URL: http://www.rhrz.uni-bonn.de/~uzs180/mpdokeng.html ------------------------------------------------------------------