PORTIBM PC Portable (uses same BIOS as XT) xxxx - Future Domain TMC-3260 PCI SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. adapter
Range:	anywhere on 8 byte boundary???
Note:	Future Domain TMC-3260 PCI SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. adapter is based upon Future Domain
	  TMC-36C70 SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controller which is a PCI version of the TMC-18C30
	  ISA(Industry-Standard Architecture) The expansion bus used by the IBMInternational Busiuness Machines PCIBM PC/ATIBM PC AT.  See also EISA. SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controller
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0140h-014Fh"Future Domain TMC-16x0"
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) xxxx - AMD Am53C974A PC-SCSI II SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. adapter
Range:	anywhere, on a 128-port boundary
SeeAlso: #00925

+000  R-  current transfer count register (low)
+000  -W  start transfer count register (low)
+004  R-  current transfer count register (middle)
+004  -W  start transfer count register (middle)
+008  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. FIFO register
+00C  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. command register
+010  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. status register
+010  -W  destination ID
+014  R-  interrupt status
+014  -W  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. timeout
+018  R-  internal state
+018  -W  synchronous transfer period
+01C  R-  current FIFO/internal state
+01C  -W  synchronous offset
+020  RW  control register 1
+024  -W  clock factor
+028  -W  reserved
+02C  RW  control register 2
+030  RW  control register 3
+034  RW  control register 4
+038  R-  current transfer count register (high) / ID code
+038  -W  start current transfer count (high)
+03C	  reserved
+040  RW  DMAsee Direct Memory Access command
+044d RW  DMAsee Direct Memory Access starting transfer count (bits 23-0)
+048d RW  DMAsee Direct Memory Access starting physical address
+04C  R	  DMAsee Direct Memory Access working byte counter
+050d R	  DMAsee Direct Memory Access working address counter
+054  R	  DMAsee Direct Memory Access status register
+058d RW  DMAsee Direct Memory Access starting memory descriptor list address
+05Cd R	  DMAsee Direct Memory Access working memory descriptor list counter
+070d Rw  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. bus and control (bits 25-24 and 21-0)
Notes:	the SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. registers are mapped on DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address. boundaries, even though for most
	  only the least-significant byte is used
	see "Am53C974A PCscsi™ II Technical Manual, Revision 1.0"
	  (file 19113A.PDF) for further details, as well as (file 19084A.PDF)
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) xxxx - Adaptec AHA-2920 PCI SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. adapter
Range:	anywhere on 8 byte boundary???
Note:	Adaptec AHA-2920 PCI SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. adapter is based upon Future Domain TMC-36C70
	  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controller which is a PCI version of Future Domain TMC-18C30 ISA(Industry-Standard Architecture) The expansion bus used by the IBMInternational Busiuness Machines PCIBM PC/ATIBM PC AT.  See also EISA.
	  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controller
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0140h-014Fh"Future Domain TMC-16x0"
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) xxxx -  Adaptec AIC-78xx PCI SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controller
Range:	anywhere on 256-byte boundary
Note:	Adaptec AIC-78xx SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controllers are basically compatible with the
	  AIC-777x SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controllers
SeeAlso: PORTIBM PC Portable (uses same BIOS as XT) 0340h-035Fh"Adaptec AHA-152x",PORTIBM PC Portable (uses same BIOS as XT) 1C00h-1CBFh"Adaptec AIC-777x"

+000  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. sequence control register (SCSISEQ) (see #P0600)
+001  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. transfer control register 0 (SXFRCTL0) (see #P0979)
+002  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. transfer control register 1 (SXFRCTL1) (see #P0980)
+003  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. control signal read  register (SCSISIGI) (see #P0603)
+003  -W  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. control signal write register (SCSISIGO) (see #P0604)
+004  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. rate control register (SCSIRATE) (see #P0981)
+005  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. ID register (SCSIID) (see #P0982)
+006  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. latched data low register (SCSIDATL)
	  read/write causes -ACK to pulse
+007  RW  (Wide SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE.) SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. latched data high register (SCSIDATH)
	  read/write causes -ACK to pulse
+008  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. transfer count register (STCNT) (3 bytes long)
+00B  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. status register 0 (SSTAT0) (see #P0607)
+00B  -W  clear SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. interrupt register 0 (CLRSINT0) (see #P0983)
+00C  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. status register 1 (SSTAT1) (see #P0609)
+00C  -W  clear SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. interrupt register 1 (CLRSINT1) (see #P0610)
+00D  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. status register 2 (SSTAT2) (see #P0984)
+00E  R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. status register 3 (SSTAT3) (see #P0612)
+00F  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. test control register (SCSITEST) (see #P0985)
+010  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. interrupt mode register 0 (SIMODE0) (see #P0616)
+011  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. interrupt mode register 1 (SIMODE1) (see #P0617)
+012  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. data bus low register (SCSIBUSL)
+013  RW  (Wide SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE.) SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. data bus high register (SCSIBUSH)
+014d R-  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE./host address register (SHADDR)
+018  RW  selection timeout timer  register (SELTIMER) (see #P0986)
+019  RW  selection/reselection ID register (SELID)  (see #P0987)
+01D  ??  (AIC-7870) board control register (BRDCTL) (see #P1051)
+01E  RW  (AIC-787x/788x) serial EEPROM control register (SEECTL) (see #P1052)
+01F  RW  SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. block control register (SBLKCTL) (see #P1053)
+020  RW  scratch RAM(Random Access Memory)	See also DRAM, SRAM. (64 bytes) (see #P1002)
+060  RW  sequencer control  register (SEQCTL)	(see #P0989)
+061  RW  sequencer RAM(Random Access Memory)	See also DRAM, SRAM. data register (SEQRAM)
+062w RW  sequencer address  register (SEQADDR) (see #P0990)
+064  RW  accumulator  register (ACCUM)
+065  RW  source index register (SINDEX)
+066  RW  destination index register (DINDEX)
+069  R-  all ones register (ALLONES)
	  always reads as FFh
+06A  R-  all zeros register (ALLZEROS)
	  always reads as 00h
+06B  R-  flags register (FLAGS) (see #P0991)
	  PhaseEngine processor's flags
+06C  R-  source indirect register (SINDIR)
+06D  -W  destination indirect register (DINDIR)
+06E  RW  function 1 register (FUNCTION1)
+06F  R-  "STACK"
+084  RW  DSCommand register (DSCOMMAND) (see #P1054)
+085  RW  bus on/off time register (BUSTIME) (see #P0993)
+086  RW  (AIC-7870) "DSPCISTATUS"
+087  RW  host control register (HCNTRL) (see #P0995)
+088d RW  host address register (HADDR)
+08C  RW  host counter register (HCNT) (3 bytes long)
+090  RW  sequence control block (SCB) pointer register (SCBPTR)
+091  RW  interrupt status register (INTSTAT) (see #P0996)
+092  R-  hard error register (ERROR) (see #P0997)
+092  -W  clear interrupt status register (CLRINT) (see #P0998)
+093  RW  DMAsee Direct Memory Access FIFO control register (DFCNTRL)  (see #P0999)
+094  R-  DMAsee Direct Memory Access FIFO status  register (DFSTATUS) (see #P1000)
+099  RW  DMAsee Direct Memory Access FIFO data register (DFDAT)
+09A  RW  SCB auto-increment register (SCBCNT) (see #P1001)
+09B  RW  queue in FIFO register (QINFIFO)
	  write places the value into the FIFO, read removes
+09C  R-  queue in count register (QINCNT)
	  number of the SCBs in the queue in
+09D  -W  queue out FIFO register (QOUTFIFO)
	  read removes the value from the FIFO
+09E  R-  queue out count register (QOUTCNT)
	  number of the SCBs in the queue out
+0A0  RW  SCB array (32 bytes) (see #P1003)
Note:	AIC-7850 SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. controllers sporatically get garbage in the MSBs of the
	  queue in/out count registers (QINCNT/QOUTCNT)


Bitfields for AIC-7870 board control register (BRDCTL):
Bit(s)	Description	(Table P1051)
 7	"BRDDAT7"
	(read) (ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank 0) internal 68-pin connector (INT68)
	=0 present
	=1 absent
	(read) (ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank 1) EPROM present (EPROMPS)
 6	"BRDDAT6"
	(read) (ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank 0) internal 50-pin connector (INT50)
	(read) (ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank 1) external 68-pin connector (EXT68)
	=0 present
	=1 absent
	(write) wide termination enable
 5	(write) "BRDDAT5"
	ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank setting
	=0 select bank 0
	=1 select bank 1
 4	strobe (BRDSTB)
 3	chip select (BRDCS)
 2	"BRDRW"
	=0 write
	=1 read
 1	"BRDCTL1"
 0	"BRDCTL0"
Notes:	accessing this register requires prior setting of bits 3 and 5 of the
	  serial EEPROM control register (SEECTL)
	bit 3 must be set to read/write bits 7-5, and reset afterwards
	bit 4 must be set along with bit 3 for writes, then value must be set
	  into the bits 7-5, and then bit 4 must be reset
	to read from bits 7-6 first perform a write operation of bit 5 in order
	  to select the ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. bank 0, then bit 2 must be set along with bit 3,
	  and then the data can be read
SeeAlso: #P1052


Bitfields for AIC-787x/788x serial EEPROM control register (SEECTL):
Bit(s)	Description	(Table P1052)
 7	"EXTARBACK"
 6	"EXTARBREQ"
 5	serial EEPROM memory port select? (SEEMS)
 4	serial EEPROM ready (SEERDY)
 3	serial EEPROM chip select (SEECS)
 2	serial EEPROM clock (SEECK)
 1	serial EEPROM data out (SEEDO)
 0	serial EEPROM data in  (SEEDI)
Notes:	AIC-7873/7883 use 93C56/93C66 serial EEPROM chips, others use 93C46;
	  93C46 serial EEPROM chips have 1024 bits organized into 64 16-bit
	  words and use 6 bits to address each word, while 93C56/93C66 chips
	  have 2048 bits organized into 128 16-bit words and use 8 bits to
	  address each word
	only the first 32 words of serial EEPROM are used by the Adaptec BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly.
	bits 3-0 are connected to the chip select, clock, data out, and data in
	  pins of the serial EEPROM respectively
	data in pin of the serial EEPROM can be read through the bit 0 of this
	  register after the clock pin goes from high to low
	bit 2 must be pulled high and then low for a minimum of 750 and 250 ns
	  to provide clocking for the EEPROM chip
	bit 2 going from low to high causes the EEPROM chip to sample the data
	  out pin and initiates the next bit to be sent through the data in pin
	bit 3 must be set for a minimum of 1 mcs with the bit 2 goig high and
	  then low for the EEPROM chip to be selected; then the instruction can
	  be sent to the EEPROM chip
	instruction can be terminated by taking the EEPROM chip select pin low,
	  with the bit 2 going high and low
	bit 5 requests access to the memory port; when access is granted, bit 4
	  will be set; during the EEPROM access bit 4 is cleared after writing
	  this register and goes high 800 ns later
SeeAlso: #P1007,#P1051,#P1055,#P1056


Bitfields for SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. block control register (SBLKCTL):
Bit(s)	Description	(Table P1053)
 7	diagnostic LED enable (DIAGLEDEN)
 6	diagnostic LED on (DIAGLEDON)
 5	auto flush disable (AUTOFLUSHDIS)
 4	reserved
 3	select bus (SELBUS)
	=0 select bus A
	=1 select bus B (SELBUSB)
 2	reserved
 1	"SELWIDE"
 0	reserved
Note:	clearing bits 7-6 will take the card out of diagnostic mode and make
	  the host adapter LED follow bus activity
SeeAlso: #P0988


Bitfields for DSCommand register (DSCOMMAND):
Bit(s)	Description	(Table P1054)
 7	cache threshold enable (CACHETHEN)
 6	data   parity check enable (DPARCKEN)
 5	memory parity check enable (MPARCKEN)
 4	external request lock (EXTREQLCK)
 3-0	reserved


(Table P1055)
Values for the 93C56/93C66 serial EEPROM instructions:
Opcode	     Function  Parameter  Description
0000xxxxxxb  EWDS      -	  disable all programming instructions
0001xxxxxxb  WRAL      D15..D0	  write to all registers
0010xxxxxxb  ERAL      -	  erase all registers
0011xxxxxxb  EWEN      -	  write enable
				  must precede all programming modes
01AAAAAAAAb  WRITE     D15..D0	  write register with address A7..A0
10AAAAAAAAb  READ      -	  read registers starting with address A7..A0
11AAAAAAAAb  ERASE     -	  erase register with address A7..A0
SeeAlso: #P1007,#P1052


Format of the serial EEPROM:
Address	Size	Description	(Table P1056)
 00h  16 WORDs	SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. ID configuration (see #P1009)
 10h	WORD	BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. control (see #P1057)
 11h	WORD	host adapter control (see #P1058)
 12h	WORD	bus release time / host adapter ID (see #P1013)
 13h	WORD	maximum targets (see #P1014)
 14h  11 WORDs	reserved
 1Fh	WORD	checksum
SeeAlso: #P1052


Bitfields for the serial EEPROM BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. control word:
Bit(s)	Description	(Table P1057)
 15-8	reserved
 7	extended translation enabled (CFEXTEND)
 6-5	reserved
 4	support more than 2 drives (CFSM2DRV)
 3	reserved
 2	BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. enabled (CFBIOSEN)
 1	support removable drives for boot only (CFSUPREMB)
 0	support all removable drives (CFSUPREM)
SeeAlso: #P1056


Bitfields for the serial EEPROM host adapter control word:
Bit(s)	Description	(Table P1058)
 15-7	reserved
 6	reset SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. bus at IC initialization (CFRESETB)
 5	reserved
 4	SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. parity (CFSPARITY)
 3	SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. high byte termination (CFWSTERM)
 2	SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. low  byte termination (CFSTERM)
 1	(Ultra SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE.) Ultra SCSI(Small Computer Systems Interface) A system-independent expansion bus typically used to connect hard disks, tape drives, and CD-ROMs to a computer.	A host adapter connects the SCSI bus to the computer's own bus.  See also ESDI, IDE. speed enable (CFULTRAEN)
 0	reserved
SeeAlso: #P0600,#P0979,#P0980,#P0994,#P1056
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) xxxx - Intel 82371, OPTi "Vendetta" (82C750) - Bus Master IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. Registers

+000  RW  command register, primary channel (see #P1092)
+002  Rw  status register, primary channel (see #P1093)
+004d RW  IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. descriptor table pointer, primary channel (see #P1094)
+008  RW  command register, secondary channel (see #P1092)
+00A  Rw  status register, secondary channel (see #P1093)
+00Cd RW  IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. descriptor table pointer, secondary channel (see #P1094)


Bitfields for Intel 82371 Bus Master IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. command register:
Bit(s)	Description	(Table P1092)
 7-4	reserved
 3	bus master read/write control
	=0 read
	=1 write
 2-1	reserved
 0	start/stop bus master
	=1 start
	=0 stop
SeeAlso: #P1093,#P1094


Bitfields for Bus Master IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. status register:
Bit(s)	Description	(Table P1093)
 7	(Intel) reserved (0)
	(OPTI "Vendetta") both channels operable at same time (read-only)
 6	drive 1 is DMA-capable
 5	drive 0 is DMA_capable
 4-3	reserved
 2	IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. interrupt pending
	write 1 to this bit to clear it
 1	IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. DMAsee Direct Memory Access error
	write 1 to this bit to clear it
 0	bus master IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. active (read-only)
SeeAlso: #P1092,#P1094


Bitfields for Bus Master IDE(Integrated Drive Electronics) A type of disk drive interface which essentially extends the PCIBM PC's expansion bus all the way to the drive and places the drive controller on the disk drive itself.	 See also ESDI. descriptor table pointer register:
Bit(s)	Description	(Table P1094)
 31-2	descriptor table base address bits 31-2
 1-0	reserved (0)
Notes:	(Intel 82371) the descriptor table must not cross a 4K boundary
	(OPTi "Vendetta") the descriptor table must not cross a 64K boundary
SeeAlso: #P1092,#P1093