** This is the quasi-official and semi-temporary T13 email list server. **
DID I GET IT RIGHT? Answer: NOT QUITE. Here is updated algorithm...
So lets assume you are running on a stupid x86 with little endian
byte ordering and you have the 48-bit LBA in some memory area
(most likely stored in a 64-bit data area) like this:
addr LBA
offset bits
------ ----
0 7-0
1 15-8
2 23-16
3 31-24
4 39-32
5 47-40
6 not used
7 not used
The updated/corrected algorithm would look like this (and
I added Sector Count too):
if ( 48-bit_command )
{
write bits 15-8 of sector count to Sector Count;
write offset 3 to Sector Number (LBA 31-24);
write offset 4 to Cylinder Low (LBA 39-32);
write offset 5 to Cylinder High (LBA 47-40);
write 40H (LBA=1) OR'ed with DEV to Drive/Head;
}
write bits 7-0 of sector count to Sector Count;
write offset 0 to Sector Number (LBA 7-0);
write offset 1 to Cylinder Low (LBA 15-8);
write offset 2 to Cylinder High (LBA 23-16);
if ( 28-bit_command )
{
write 40H (LBA=1) OR'ed with DEV
OR'ed with bits 3-0 of offset 3
to Drive/Head (LBA 27-24);
}
I think this is "more correct"?
*** Hale Landis *** [EMAIL PROTECTED] ***
*** Niwot, CO USA *** www.ata-atapi.com ***
--
If you have any questions or wish to unsubscribe send a
message to Hale Landis, [EMAIL PROTECTED] To post to
this list server send your message to [EMAIL PROTECTED]
For questions concerning Thistle Grove Industries or TGI's
list services please send email to [EMAIL PROTECTED]
