In reply to: Bret Johnson <bretjohn@ju...>

>> only support Intel/Via (UHCI) controllers yet.

> True.  Working on that.

Great :=)

>> I also think they have hard coded 512 bytes per sector.

> No.  USBDRIVE reads the maximum buffer size from the DOS List of Lists (as 
> discussed some earlier in the thread), and uses that as its maximum sector 
> size.  If a USB disk has 4k sectors, but DOS can only handle 512 byte 
> sectors, USBDRIVE won't load the disk.  If DOS can handle (buffer) 4k sectors 
> OK, USBDRIVE will load it and automatically mount any FAT partitions it finds.

TY for the heads-up. 

>  Also as stated earlier, I don't personally have any disks with sector sizes 
> other than 512, so this has never been tested (at least by me) on a real 
> system.

It would be a good thing if someone on the list having access to such a device 
/and/ Intel-based USB would experiment and report their findings...


> That's why you need to modify the kernel to handle 4k sectors, also as 
> discussed earlier (at least with my drivers).  Based on what Eric says, 
> though, that doesn't work with the FreeDOS kernel.

As I noted earlier, I'm sure the default disk driver MS DOS kernels can handle 
bigger sectors, /but/ there are problems to be fixed - as pointed to me by R. 
Loew, and I verified it too : MSDOS init module (patition scanner) discards 
partitions whose boot sectors indicate any sector size other than 512. Disks 
operated through user drivers (config.sys) should not be so limited.

While trying a free fix for MSDOS could be attempted - but is the effort worth 
it ? - I would vote for FreeDOS to be enhanced.

Does someone here know if DR/Open DOS recognises >512k sectors, either or both 
with its built-in disk driver and user drivers ?


> Because USBDRIVE provides an INT 13h interface, you can also use external 
> drivers to mount/access the non-FAT partitions that may be on the USB disks 
> (NTFS, EXTx, exFAT, ...).  USBDRIVE won't mount non-FAT drives automatically, 
> though.

Understood.


Regards


-- 
Czerno

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