braner@batcomputer.tn.cornell.edu (braner) (01/18/88)
[] Examination of the boot sector and first FAT sector of the C: partition of my Atari SH204 hard disk (formatted by the HDX utility with the default 4-6-10 partitioning) shows the following: (all in hex) Start of boot sector: 00 04 3E 3C 00 E0 4E 75 24 48 65 00 02 02 01 00 20 00 01 90 22 73 12 00 70 2E 73 2C 76 20 31 2E 31 20 38 36 2F 30 36 2F 30 32 20 31 32 3A 34 38 * 1 86/06/02 12:48 3A 34 31 20 64 79 65 72 20 45 78 70 20 24 00 4D * :41 dyer Exp $.M - meaning: BPS=200 SPC=2 RES=1 DIR=100 NSECS=2290 FATS=20 MEDIA=73 SPF=12 SPT=2E70 SIDES=2C73 HIDDEN=2076 SERIAL=312076 At the end of the boot sector: 01 47 45 4D 00 00 52 91 00 00 50 00 00 47 45 4D * .GEM..R...P..GEM 00 00 A2 91 00 00 00 00 00 00 00 00 00 00 2F 7C * ............../| The start of the FAT: 00 00 00 00 FF FF 04 00 05 00 06 00 07 00 08 00 FF FF FF FF FF FF FF FF FF FF 0E 00 0F 00 FF FF FF FF 12 00 FF FF FF FF 15 00 FF FF 17 00 18 00 19 00 FF FF 7C 03 FF FF 1D 00 1E 00 1F 00 20 00 21 00 22 00 23 00 24 00 25 00 26 00 27 00 28 00 FF FF 2A 00 2B 00 2C 00 2D 00 2E 00 2F 00 30 00 - i.e., looks distinctly like *** 16-bit *** entries. Question: can somebody out there who knows about MS-DOS figure out the corrections necessary so that MS-DOS (3.3) would read the partition right? As-is it gets it all wrong except the root directory, so I suspect MS-DOS reads the FAT as 12-bit entries. Possibly: the media type is wrong, or it needs to be duplicated in the first byte of the FAT? - Moshe Braner