HP Vectra Technical Reference Manual page 254

8.2.2 Diskette Parameter Table
The diskette parameter table contains information that controls the overall operation of the
flexible disc controller. This table is pointed to by INT 1EH (O:78H). A default table is provided in
the ROM BIOS at address OFOOOH:OEFC7H. The parameters used to control the NEC flexible disc
controller can be changed by providing a new diskette parameter table pointer in INT 1EH
(O:78H). This is detailed in table 8.2.
Table 8.2
Diskette Parameter Table
Length
Offset in Bytes
OOH
1
01H
1
02H
1
03H
1
04H
1
OSH
1
06H
1
07H
1
08H
1
09H
1
OAH
1
Description
NEC Specify command byte 1: step-rate time and head unload
time
NEC Specify command byte 2: head load time and DMA mode
Motor wait time
Bytes per sector; 0
=
128, 1
=
256, 2
=
512
Last sector number on track
Read/write gap length between sectors
Data length for read/write operations
Format gap length between sectors
Format filler byte
Head settle time after seek command
Motor start time in
' / 8
seconds
8.2.3 Diskette Status Table
The status table for the internal flexible disc driver begins at memory location 0040:003EH
(0043EH) in the STD-BIOS Data Area. The contents of this table are listed in table 8.3.
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