HP dx7300 Technical Reference Manual page 85

Primary Second.
Address Address Register
3F4h
3F5h
3F6h
3F7h
NOTE: The most recently written data rate value to either DRSR or CCR will be in effect.
Technical Reference Guide
Table 5-5. (Continued)
Diskette Drive Interface Control Registers
374h Main Status Register (MSR):
<7> Request for master (host can transfer data) (active high)
<6> Transfer direction (0 – write, 1 = read)
<5> non-DMA execution (active high)
<4> Command busy (active high)
<3,2> Reserved
<1,0> Drive 1, 2 busy (active high)
Data Rate Select Register (DRSR):
<7> Software reset (active high)
<6> Low power mode enable (active high)
<5> Reserved (0)
<4..2> Precompensation select (default = 000)
<1,0> Data rate select (00 = 500 Kb/s, 01 = 300 Kb/s, 10 = 250
Kb/s, 1 1 = 2/1 Mb/s)
375h Data Register:
<7..0> Data
376h
377h
<7> DSK CHG status (records opposite value of pin)
Configuration Control Register (CCR):
<1,0> Data rate select (00 = 500 Kb/s, 01 = 300 Kb/s, 10 = 250
Reserved
Digital Input Register (DIR):
<6..0> Reserved (0's)
<7..2> Reserved
Kb/s, 1 1 = 2/1 Mb/s)
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Input/Output Interfaces
R/W
R
W
R/W
--
R
W
5-7