User`s manual

DIGITAL-LOGIC AG MSMP5 / P3 SEN/SEV Manual V1.6A
69
BIOS Data Area Definitions Continued...
Location Description
3Fh Diskette Drive Motor Status
bit 7 = Current operation
0 = Write or Format
1 = Read or Verify
bit 6 = Reserved
bits 5-4 = Drive Select
00 = Drive A
01 = Drive B
bits 3-2 = Reserved
0 = Disable
1 = Enabled
bit 1 = Drive B Motor Status
0 = Off
1 = On
bit 1 = Drive A Motor Status
0 = Off
1 = On
40h Diskette Drive Motor Timeout
Disk drive motor is powered off when the value via the INT 08h
timer interrupt reaches 0.
41h Diskette Drive Status
bit 7 = Drive Ready
0 = Ready
1 = Not ready
bit 6 = Seek Error
0 = No error
1= Error occurred
bit 5 = Controller operation
0 = Working
1 = Failed
bits 4-0 = Error Codes
00h = No error
01h = Invalid function requested
02h = Address mark not located
03h = Write protect error
04h = Sector not found
06h = Diskette change line active (door
opened)
08h = DMA overrun error
09h = Data boundary error
0Ch = Unknown media type
10h = ECC or CRC error
20h = Controller failure
40h = Seek operation failure
80h = Timeout
42h - 48h Diskette Controller Status Bytes
49h Video Mode Setting
4Ah - 4Bh Number of Columns on screen
4Ch - 4Dh Size of Current Page, in bytes
4Eh - 4Fh Address of Current Page
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