82091AA Datasheet, PDF (120/204 Pages) Intel Corporation – ADVANCED INTEGRATED PERIPHERAL (AIP)

82091AA
Figure 58 Enhanced Tape Drive Register
290486 – 58
Bit
Description
7 3 RESERVED
2 BOOT DRIVE SELECT (BOOTSEL) The BOOTSEL bit is used to remap the drive selects and
motor enables The functionality is as described below
BOOTSEL
0
1
Mapping
x x DS0 FDS0 ME0 FDME0 (default)
DS1xDS1 x ME1 FDME1
DS0xDS1 x ME0 FDME1
DS1xFDS0 x ME1 FDME0
Note that this mapping also applies to a four drive system (FDDQTY^e1 in the FCFG1 Register) In a
four drive system only drive 0 or drive 1 can be selected as the boot drive
1 RESERVED For a two-drive system this bit is not used and must be programmed to 0 For a four
drive system see Appendix A FDC Four Drive Support
0 TAPE SELECT (TAPESEL) This bit is used by software to assign logical drive number 1 to be a
tape drive Other than adjusting precompensation delays for tape support this bit does not affect the
FDC hardware The bit can be written and read by software as an indication of the tape drive
assignment Drive 0 is not available as a tape drive and is reserved as the floppy disk boot drive The
tape drive assignment is as follows
Bit 0
0
1
Drive Selected
None (all are floppy disk drives)
Drive 1 is a tape drive
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