01010101100110101010110011010101011001101010101100110101010110011010101011001101010101100110
100110101010110011010101011001101010101100110101010110011010101011001101010101100110101010110011010101011011010101011
10101010110011010101011011010101001101010100110101101101101010100101
1011010101100110011010101011010101111010111
11010101101101010100111110
1101110110110011
0111011110
111101
011
11
1
Seagate
PC-3000 EXPRESS / UDMA / PORTABLE
F3 architecture
ACE Lab
Technical support: [email protected]
Phone: +7 863 201 50 06
34
ts.acelaboratory.com
returns specifically the active map address, it may be corrected individually in RAM. If the drive returns the address of
maps array, correction requires editing of the entire array (because there is no way to tell, which of them is being used).
On that level the heads are numbered sequentially from 0 to the last head number. Nothing can be skipped in the
middle.
The map for translation of logical heads into physical ones occupies a higher level in the hierarchy. It makes it possible
to create HDD models with heads disabled in the middle of the stack provided their firmware supports this table. The
map should be taken into account while selecting a donor heads stack. If the map is supported, you can view it on a
functional HDD or in ROM image. According to the table, the "logical" head numbers are converted into "physical"
ones as indexes in the table for conversion into the commutator channel selection code.
E.g.:
Logical head, table index 0
1
2
3
→
Physical head,
table index
0
1
2 3
4
5
Physical head
0
1
4
5
Preamplifier code
a
b
c d
e
f
In the provided example heads 2 and 3 are disabled (skipped). Let us assume that logical head 2 is damaged.
Consequently, to obtain the physical head number you have to use the number in cell
2
from the logical heads
translation table. The number is
4
. It means that we have to deal with the physical head 4. The number in cell under
index 4 from the table for conversion into the preamplifier codes produces code
e
. It means that to exclude the damaged
head from the translation process you have to replace in the map for conversion of logical heads into physical ones the
number
4
with the number corresponding to a live head (e.g.,
1
= log. head 1), or replace in the preamplifier code
selection table the code
e
with a code corresponding to a live head (e.g.,
b
= phys. head 1 = log. head 1). Thus, the
resulting head maps will look as follows:
Logical head, table index 0
1
2
3
→
Physical head,
table index
0
1
2 3
4
5
Physical head
0
1 1
5
Preamplifier code
a
b
c d
b
f
Attention!
While working with the maps of drive heads, please keep in mind that firmware is located in areas
accessible with the heads 0 and 1. Therefore, you cannot exclude both of them because it will prevent normal
functioning of the HDD.
Fig. 6.11
Fig. 6.12
