CONFIGURATION CONTROL REGISTER (CCR)
Address 3F7 WRITE ONLY
PC/AT and PS/2 Modes
7
6
5
4
3
2
1
0
DRATE DRATE
SEL1 SEL0
RESET N/A N/A N/A N/A N/A N/A
1
0
COND.
BIT 0 and 1 DATA RATE SELECT 0 and 1
These bits determine the data rate of the floppy controller.
See Table 13 for the appropriate values.
PS/2 Model 30 Mode
BIT 2 - 7 RESERVED
Should be set to a logical "0"
7
6
5
4
3
2
1
0
NOPREC DRATE DRATE
SEL1 SEL0
RESET N/A N/A N/A N/A N/A
N/A
1
0
COND.
BIT 0 and 1 DATA RATE SELECT 0 and 1
These bits determine the data rate of the floppy controller.
See Table 13 for the appropriate values.
BIT 2 NO PRECOMPENSATION
This bit can be set by software, but it has no functionality.
It can be read by bit 2 of the DSR when in Model 30
register mode. Unaffected by software reset.
BIT 3 - 7 RESERVED
Should be set to a logical "0"
Table 13 shows the state of the DENSEL pin. The
DENSEL pin is set high after a hardware reset and is
unaffected by the DOR and the DSR resets.
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