Commodore Amiga A500 Technical Reference Manual page 189

No error, invalid command. invalid sector address, invalid
LUN,
drive
not ready, write fault, DMA error.
Set
Drive Parameters
Action
(Class 0, Opcode C)
This command points to a 6 byte block of memory. specified by bytes
6 and 7 of the command block, that sets the following parameters
for both of the hard disk drives (logical units 0 and 1):
Table 5-9. Set Drive Parameters
If
the above command is not executed after power up o r every reset,
the HDC will assume the following default parameters:
D7
I
D6
1
D5
1
D4
User Options
0
1
Num. of Heads
Number of cylinders (131 hex)
Number of heads
Starting write precompensation cylinder
Reduce write current cylinder
Step rate
Maximum length of an error bust t o be corrected
Number of sectors per track
Retries & ECC enable
D3 D2
I
D1
I
DO
Step Rate
CYL. Nums. MSN
The acceptable range of values for these parameters are as follows:
Number of Cylinders LSB
Precompensation Cylinder
1
16
Reduce Write Current Cylinder
/ 16
Number of Sector per Track
0
-
2047. Number of cylinders
0 - 7
Number of heads
0
-
2 5 5 Sector Numbers
0
-
1023. Starting write precompensation cylinder
5 1 11. Maximum length of error burst t o be corrected
0 1 8 Retries
If one of the parameters is out of range, then an "invalid command"
error code is generated by the HDC. Bytes 2 and
5
of table are self
explanatory and will not be discussed any further.
User Options