F71869A
Data rate table select, refer to table A.
00: select regular drives and 2.88 format.
01: 3-mode drive.
4-3
FDD_DRT
R/W
00
10: 2 mega tape.
11: reserved.
2
Reserved
FDD_DT
-
-
Reserved.
1-0
R/W
00
Drive type select, refer to table B.
TABLE A
Data Rate Table Select
Data Rate
Selected Data Rate
DENSEL
FDD_DRT[1] FDD_DRT[0] DATARATE1 DATARATE0
MFM
500K
300K
250K
1Meg
500K
500K
250K
1Meg
500K
2Meg
250K
1Meg
FM
250K
150K
125K
---
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
0
1
0
1
250K
250K
125K
---
250K
---
0
125K
---
Drive Type
DRVDEN0
DENSEL
Remark
FDD_DT1
FDD_DT0
0
4/2/1 MB 3.5”
0
2/1 MB 5.25”
1/1.6/1 MB 3.5” (
0
1
1
1
0
1
DATARATE1
DENSEL#
DATARATE0
TABLE B
66
Oct., 2011
V0.19P