On Sat, Feb 4, 2012 at 3:13 PM, Bertho Grandpied <y31415926...@yahoo.fr> wrote: > > Hi, Guys! Replying to self, sort of, and Jeremy at the same time. > I've been glancing thru the ram disk, TDSK, source. Internal buffer (used for > init only) was provisionned for one 4K sector, but for some reason author(s) > limited sector size to 2K, as specified on the driver's command line. > > I boldly hacked the binary so it ignored the limitation and, behold, a first > quick and (very) dirty test of a ~8 MBytes FAT12 based RAM disk *with 4096 > byte sectors* in MS-DOS 7.1 with a rather fully loaded config SUCCEEDED! I > was able to copy several megabyte files to/from the ramdisk (quick tests did > include binary compare fo source to dest, and an examination of the RAMdisk > with Norton's DISKEDIT revealed no problems). > > > I'm not affirming yet there are no hidden bugs but, clearly, MSDOS CAN > support this type of device with no or little problems ! This to me is great > news, since it makes it worth developing a simple ASPI to DOS convertor for > use with my external USB disk. MSDOS bugs, if any, may be limited to > installing large sectored units which are to be managed by IO/MSDOS.SYS > internal disk driver. > > Jeremy wrote : >> (currently not while testing). ?I have tested 256, 512, >> 1024, and 2048 >> byte sectors with tdsk (currently my only way to test). > > > You may try to force TDSK to allow 4096 bps (not more without recompilation) > by nullifying the sanity test for command-line size-of-sector, like I did ! > > > Czerno >
For testing only - warning may corrupt data!!! https://www.fdos.org/kernel/testing/4K/ Included is a test kernel supporting 4KB sectors, note it limits buffers to 2 to avoid memory corruption on boot. Also there is tdsk 3.2 with patch to allow 4KB sectors assembled with jwasm. source can be found on sf fdos svn - hack to limit buffers to 2 not there but available on request. this kernel is there to allow testing with drive that exposes non 512 byte sectors only and will be removed without notice. Thanks for testing, Jeremy ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
