At 07:47 AM 2/24/2006 -0500, Mark Bailey wrote:
Very interesting. I am a naive user here. How do I tell if my USB sticks are formatted as floppies or hard drives?
If you don't have a low-level disk editor of some type, you can either use Bart's utilities' MKBT to read a boot disk image from the flash disk and examine it for a valid partition information etc., or you can use DEBUG's 'L' command to load the first sector in memory and look at things there.
Is this a function of FreeDOS or WindowsXP format?
Either one here makes no difference as far as hard drive status. You need partition tables and I dunno exactly what else to flag a hard drive. I could punch in the numbers directly, but building your own partition table by hand strikes me as more than a little tedious, particularly if you have to route around it in the boot loader. Not sure how that works, I suppose you increase the sector size so there's enough room for the loader and the partition table to co-exist, or maybe it's something to do with hidden sectors. I used to be more knowledgeable after making my first stick bootable by hand, but it's been a while and not the sort of information one tends to retain without good reason.
All my sticks have an MBR in the first 512 bytes. Are you saying that yours do not?
No, they have a MBR, but they don't have partitions at offset 1BE-1FE of the first sector. Rather, the bytes are used by the boot loader code as part of launching KERNEL.SYS. They are garbage when interpreted as partition values -- except, as I said, for the one time I got hard drive status going on the stick.
Also, what is the "media byte" status? Is this the "media descriptor" at offset 15h in the FAT32 boot sector?
Yeah, media descriptor byte. F8 is hard drive, but it's pretty much ignored in all my boot tests. Things do or don't come up the same way regardless of whether I specify F0 or F8.
Also, does the machine in question have a floppy disk drive?
Yes. If I boot the USB stick (into A:) the floppy is still accessible as B:. ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ Freedos-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-devel
