FAT16 help needed!!!

Other removable media, such as zip drives, also use an MBR even though windows can only cope with a single partition on it (other OS's can use more).

Hi Jim,

the code is GPL, and I'm waiting for Pat Villani's (the author of FreeDOS) feedback on this work. The homepage of the project is

and the whole project should be on-line by the end of the month.

Enrico

Hi

That might be the answer. I'll check.

yes, sorry. I didn't do it on purpose.

The size of a block can be any number of sectors. Old 360K or 720K format used normaly 2 sectors. 1.44M floppies used 1 sector blocks. How many blocks you'll need depends on the size of a FAT entry and the size of the medium.

The first block starts after the root directory, IIRC its sector address is: 1 (for boot sector) + # of hidden sectors + # of FATs * # of sectors per FAT + # of sectors for the root directory.

Ah, and yes, sector numbers start with 1, blocks with 0.

--
42Bastian
Do not email to bastian42@yahoo.com, it's a spam-only account :-)
Use @epost.de instead !

Don't know the media type, but some BIOSes need USB-memorysticks configured as if it where a floppy, i.e. no MBR only an boot sector.

Maybe some of these sticks hide the MBR if they are not accessed by the right driver ?!

--
42Bastian
Do not email to bastian42@yahoo.com, it's a spam-only account :-)
Use @epost.de instead !

Other OS's don't have to use the MBR scheme of partitions either. MBR is really only needed so that the BIOS can figure it out.

--
Darin Johnson
    Gravity is a harsh mistress -- The Tick

chip I

then

the

Well, I tried today to duplicate it but it's not working like it did before. Generally here are the steps I followed back when this worked for me, this is for uFlashTCP:

On the PC:

1) Download the latest FreeDOS and make sure these files are handy:

SYS.com, KERNEL.sys, KERNEL1.sys, COMMAND.com and optionally FDCONFIG.sys

The handiest way for me was to download the boot image and use Winimage to extract the files.

2) Use the SYS command to create a copy of the boot sector. Use SYS /? for help.

Here I used tftp from WATTCP and a private IP address. It's *much* faster than the Xmodem stuff and DOWN.com isn't working anyway.

On the unit:

1) Use M-Systems format command: "dformat /win:EE000" where EE000 is the address of their chip IIRC. 2) reboot 3) check C: is clean 4) use a utility that will allow you to write the boot sector, the one I use is makedisk.exe but I don't remember now where I got it from. Optionally write one, which I've also done but mine only worked for the A drive on a PC and I never updated it. Oh, and write the boot sector onto the C: drive using the image you created in PC Step 2. 5) It's fuzzy here, I can't remember if I had to create a dummy 512 area following the boot sector image or if I just proceeded. 6) Copy KERNEL.sys, KERNEL1.sys and COMMAND.com to the C: drive.

Note: According to the uFlashTCP doc I'm supposed to change the JP3 jumper to make the C: drive bootable but it seems that if I just lift the 2-4 jumper, remove and apply power then place it back before it reaches the TrueFFS driver in the boot sequence then it tries to boot from the M-Systems (C: drive) chip.

Anyway, this worked one time (way back when...) but as I said in the beginning of this post, I wasn't able to get it working today. Several times I got it to print the "FreeDOS" logo then it hangs like the jump into the DOS code fails. I tried with both 512 bytes and 1024 byte images.

Suggestions welcome and if this helps in some way, that's also great!

Dilton

Thanks for writing it up. I've gotten as far as the freedos logo too, but I'm pleased to know that you've actually gotten it to boot.

I

know

before.

this

FDCONFIG.sys

to

for

faster

use

a PC

jumper

M-Systems

times

the

I found my old files! I'm going to review them and if I get it working again I'll post the details here.

data

using

same

did

used

short

Winimage

the

I

Optionally

on

drive

area

the

again

I went back to the firmware files (downloaded them from M-Systems web site) and used my original files (which was FreeDOS 7 IIRC) and the farthest I get is:

Freedos loading... ROOT FAT KERNEL GO!

which us supposed to mean that the boot code found KERNEL.sys and attempted the jump there, then it hangs. I've successfully booted these images in a Virtual PC session (and ONCE on the M-Systems disk in the past). So to get a better understanding will require jumping into the FreeDOS source. According to the M-Systems documentation there is no bad sector management using this approach. If we were to write a custom set of firmware using their BDK then we would get bad sector management automaticaly from their source.

So I'm suggesting that this could be some sort of contigious sector issue. There are no other indications though. The writing seems to work without error, I even tried to dump the bad sector table and get only a zero length file, which I suppose means there are no bad sectors on the Flash disk. If I turn up anything new I'll probably post it new.

Dilton