braner@batcomputer.UUCP (06/16/87)
[] At long last (due to the appearance of Turbo C) I got around to transferring text files (C source) between the ST and the IBM-PC. As posted here, the IBM (equipped with a 3.5" DS drive) refuses to read a disk formatted on the ST in the normal TOS fashion. I formatted disks on the IBM, put a text file on one, then moved to the ST. It read that text OK. Next I copied a bunch of files onto the disk. As long as they were written to the root directory, no problem (and the IBM reads them fine). But when I made several subdirectories on the disk and copied files to them, the ST _crashed_ - had to reboot! I tried that several times and it always crashed. Any ideas? (I used MS-DOS 3.2 to format the disk.) BTW: MS-DOS 3.2, according to the Turbo-C docs, has a bug: The ninth FP exception crashes the OS, need to reboot. So it's not only TOS that's buggy! - Moshe Braner
dclemans@mntgfx.MENTOR.COM (Dave Clemans) (06/18/87)
About problems interchanging 3.5" disks between ST's and PC's: There are two potential problem areas: 1. The ST uses a Western Digital floppy controller chip. PC's typically use a different one (NEC or it's Intel equivalent?). Apparently under at least some circumstances the Western Digital 1772 can produce a low level format that the PC controller has trouble reading. 2. MS-DOS/PC-DOS initially put disk type information in the first entries in the disk FAT table. Later revs have moved that information to sector 0; but for compatibility reasons disk type info is normally in both sector 0 and in the first FAT entries. GEMDOS on the ST only puts the disk type info in sector 0. Therefore is a floppy driver on the PC expects to get the disk type info from the first FAT entries, it will get confused. About sub-directory problems: while I haven't tried this from a "strict" PC/clone, I have from an Amiga Transformer running PC-DOS 2.10 and 3.2. The ST had no problems reading those sub-directories. A possible cause is that GEMDOS expects to see "end-of-directory" at either the end of the sectors allocated to the directory, or with an entry that starts with a zero byte. If that wasn't the case you definitely could get a crash. dgc