In reply to : Eric Auer <>

Realising I left away this point of your previous msg :

>> Someone, maybe not Eric, asked what I have been using for accessing
>> USB mass storage in DOS. Answer : a version of Panasonic's
>> USBASPI.SYS. This allows access to 4k sectors using SCSI commands.

> Interesting, but would that be easier than using Bret's or Georg's
> USB storage drivers? 

I had a look at Bret's open source USB drivers, unfortunately they only support 
Intel/Via (UHCI) controllers yet. I also think they have hard coded 512 bytes 
per sector. In any case I only own non-Intel based (OHCI/EHCI) so can't use or 
test Bret's fine work.

Haven't looked at Georg's drivers, which are not free/open anyway and 
annoyingly, the non paid for versions stop working after a few minutes IIUW.

> As long as somebody explains me how to write
> and read 4k sectors with those drivers, I should be able to show
> how to show 512 sectors and a transformed BPB on the DOS side, in
> that way making FAT32 partitions on that disk useable by unpatched
> FreeDOS with a simple loadable block device driver in a safe* way.

I had success with Panasonic's USBASPI driver, specifically the non official 
2.27x USBASPI.SYS (15,491 bytes "dieted" DOS driver) extracted from : 
<> The download also contains other 
drivers which you may find interesting, including an USBASPI.EXE (untried by 

I'm making no representations or comment on the legality etc... but this is for 
education pruposes right ? The thing works for me, provides full ASPI access to 
the 4K sectors (32bit LBA support)

I also made limited experiments with modding the block driver DIDD1000.SYS - 
the included int 13h provider is easily "fixed", but the "DOS block device 
driver" proper would require much more disassembling and study than I could 
afford. Instead efforts should be devoted to writing an open source

> *I cannot stop you from breaking the wonder by reformatting that
> partition in a non-4k-compatible way, apart from write-protecting
> the boot sector. You cannot repartition disks through block device
> drivers anyway, so THAT part is safe. Also, DOSFSCK will be happy
> (will not notice anything strange) and CHKDSK skips FAT32 anyway.

I look forward to seeing a demo from you and hearing from the rest of the gang 
too ...


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