You are a genius... This floppy change problem has been around for some time because it is hard to reproduce. The steps 1 to 5 in problem 2 are all done from a single running program? If so it may be related to a problem I encontered a few times.
Thanks, very much Alain Koike Toshio escreveu: > Hello FreeDOS developers. > > We are using FreeDOS 1.0 in our embedded systems. FreeDOS is a good > replacement of ROM-DOS we previouslly used. Thank you for all the great work > on FreeDOS. > > I found two small problems related to Floppy disk(FD) and fixed it by > modifying FreeDOS kernel sources(2036 cvs). I send patches to fix these > problems. My patches are applicable to kernel 2036 cvs. > If you consider the patches and incorporate to your kernel tree, it should be > great for me. > > The patches are uploaded here. > http://us.f13.yahoofs.com/bc/48b6f314_185bc/bc/freedos/patch080818.zip?bfh__vIBxIiwN9fQ > > Two problems are: > > Problem 1: Maxell new FD has No 55-aa magic number in boot sector. > Problem 2: Floppy disk change recognition problem. > > ------------------------------------------------------------------------------- > Problem 1: Maxell new FD has No 55-aa magic number in boot sector. > > When we used Maxell FD, we encountered strange phenomena. We wrote files to > FD. > Write process was looking good. But there is no file in checking the FD on > Windows. > After precise investigation, I found a lack of 55-aa magic number in the last > two bytes of the boot sector of Maxell FD. FreeDOS getbpb() function is > checking 55-aa magic number. If no 55-aa magic number, FreeDOS assumes the FD > as a 720KB(not 1440KB) FD. > ---- Maxell FD boot sector dump (No 55-aa at 01feh) ---- > 00000000 eb 34 90 4d 41 58 45 4c 4c 20 20 00 02 01 01 00 |.4.MAXELL .....| > 00000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00 |[EMAIL > PROTECTED]| > 00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > * > 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > ---- TDK FD boot sector dump (There's 55-aa at 01feh) ---- > 00000000 eb 34 90 49 42 4d 20 20 33 2e 33 00 02 01 01 00 |.4.IBM 3.3.....| > 00000010 02 e0 00 40 0b f0 09 00 12 00 02 00 00 00 00 00 |[EMAIL > PROTECTED]| > 00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 12 |................| > 00000030 00 00 00 00 01 00 fa 33 c0 8e d0 bc 00 7c 16 07 |.......3.....|..| > : > 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| > -------------------------------------------------- > ROM-DOS, PC-DOS and Windows has no problem with the Maxell FD. So I think > FreeDOS is too strict in checking boot sector format. Original FreeDOS > checks 55-aa magic number and sector size (=512). My patch disables checking > of 55-aa magic number and only checks sector size. > > fdos-maxell-fd-patch-080818.diff modifies kernel/dsk.c. > > ------------------------------------------------------------------------------- > Problem 2: Floppy disk change recognition problem. > > When we write two FD on our application, the first FD's directory entries was > copied onto the second FD. This problem was not occurred on ROM-DOS and > PC-DOS. > After precise investigation, I found that our application is calling BIOS > int-13h AH=02h(Sector read) before the second FD write. > Test program DISKCHG.C demonstrates this problem through steps as follows. > 1. insert disk-1 > 2. write A:FILE1 calling DOS > 3. change FD to disk-2 > 4. read FD boot sector calling BIOS int-13h AH=02h > 5. write A:FILE2 calling DOS > Disk-2 directory entry contains two files FILE1 and FILE2. > > Normally disk change is notified on calling BIOS int-13h AH=00h-05h,08h, > 15h-18h. But disk change notification from BIOS is the ONLY ONCE. So on the > subsequent call of BIOS int-13h AH=16h(Detect disk change) from FreeDOS > kernel, no disk change will be notified and FD cache in kernel will NOT be > flushed. Then the first FD's directory data will be written into the second > FD. > > My patch introduced int-13h hooking. Disk change status on calling int-13h > AH=00h-05h,08h,15h-18h is memorized and reported on the call of > fl_diskchanged(). > Perfect disk change recognition will be accomplished by the patch. Though I > have not examined other DOSs(PC-DOS, ROM-DOS), the same hooking may be used. > > fdos-fd-change-patch-080818.diff modifies kernel/main.c and > drivers/floppy.asm. > > ------------------------------------------------------------------------------- > > Please consider my patches. > > Thanks for your reading. :-) > > Toshio Koike > > > ------------------------------------------------------------------------ > $B=)K\HV!*O"5Y$?$/$5$s$N$3$N=)!"$_$s$J$N%*%9%9%a=5KvN99T$r%A%'%C%/$7$h$&(B > $B!|[EMAIL PROTECTED]|K\A49q$I$3$X$G$b!d!d!d(B > <http://clk.atdmt.com/GBL/go/112813570/direct/01/> > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > > > ------------------------------------------------------------------------ > > _______________________________________________ > Freedos-kernel mailing list > Freedos-kernel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freedos-kernel ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
