PORTIBM PC Portable (uses same BIOS as XT) 0140-014F - 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. (alternate Small Computer System Interface) adapter
Note:	first adapter is at 0340-034F
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) 0140-014F - Xirlink/Relialogic XL-220/221 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:	alternate address at 0150, 0160, 0170
Notes:	XL-220/221 are based on LOGIC Devices L53C80JC4 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 compatible with Symbios Logic (formaerly NCR) 53C80
	each 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 pin is inverted and compared with correcponding bit
	  in the ID select register; if any matches are found while a bus free
	  condition exists and SEL is active, 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 will genarate an
	  interrupt to indicate a selection or reselection
	pseudo-DMA register is provided by some on-card PLM, and decodes any
	  address in the range 01x8-01xF; it should be accessed with 16-bit
	  I/O instructions only causing 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. REQ/ACK hanshakes (8-bit I/O
	  is treated as 16-bit, and second byte is lost); delayed assertion of
	  the REQ signal or bus free condition on 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. bus causes the
	  pseudo-DMA register to prolong ISA(Industry-Standard Architecture) The expansion bus used by the IBMInternational Busiuness Machines PCIBM PC/ATIBM PC AT.  See also EISA. I/O cycle not asserting IOCHRDY
	  signal (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. phase mismatch doesn't), and so may cause ISA(Industry-Standard Architecture) The expansion bus used by the IBMInternational Busiuness Machines PCIBM PC/ATIBM PC AT.  See also EISA. bus to
	  hang in not ready state!
	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. 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. is an 8K ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. located at C8000-CBFFF if I/O port range
	  0140-014F is selected, at CC000-CFFFF if I/O port range 0150-015F
	  is selected, at D8000-DBFFF if I/O port range 0160-016F is selected,
	  and at DC000-DFFFF if I/O port range 0170-017F is selected

0140  R-  current 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 register
0140  -W  output data register
0141  RW  initiator command register (see #P0496)
0142  RW  mode register (see #P0497)
0143  RW  target command register (see #P0498)
0144  R-  current 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 register (see #P0499)
0144  -W  ID select register
0145  R-  DMAsee Direct Memory Access status register (see #P0500)
0145  -W  start DMAsee Direct Memory Access send register
	  any write starts DMAsee Direct Memory Access send
0146  R-  input data register
	  temporarily holds data byte received from 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. bus in DMAsee Direct Memory Access mode
0146  -W  start DMAsee Direct Memory Access target receive register
	  any write starts target mode DMAsee Direct Memory Access receive
0147  R-  reset error/interrupt register
	  any read resets the interrupt request latch and the error latches
0147  -W  start DMAsee Direct Memory Access initiator mode receive register
	  any write starts initiator mode DMAsee Direct Memory Access receive
0148w RW  pseudo-DMA register


Bitfields for initiator command register:
Bit(s)	Description	(Table P0496)
 7	assert RST
 6	(read) arbitration in progress
	(write) test mode
 5	(read) lost arbitration
 4	assert ACK
 3	assert BSY
 2	assert SEL
 1	assert ATN
 0	assert data bus
SeeAlso: #P0497,#P0498,#P0499,#P0500


Bitfields for mode register:
Bit(s)	Description	(Table P0497)
 7	block mode
 6	target mode
 5	enable parity check
 4	enable parity interrupt
 3	enable end of DMAsee Direct Memory Access interrupt
 2	monitor BSY
 1	DMAsee Direct Memory Access mode
 0	arbitrate
SeeAlso: #P0496


Bitfields for target command register:
Bit(s)	Description	(Table P0498)
 7	(read) last byte sent
 6-4	reserved
 3	assert REQ
 2	assert MSG
 1	assert C/D
 0	assert I/O
SeeAlso: #P0496


Bitfields for current 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 register:
Bit(s)	Description	(Table P0499)
 7	RST
 6	BSY
 5	REQ
 4	MSG
 3	C/D
 2	I/O
 1	SEL
 0	parity
SeeAlso: #P0496


Bitfields for DMAsee Direct Memory Access status register:
Bit(s)	Description	(Table P0500)
 7	end of DMAsee Direct Memory Access
 6	DMAsee Direct Memory Access request
 5	parity error
 4	interrupt request
 3	phase match
 2	BSY error
 1	ATN
 0	ACK
SeeAlso: #P0496
                                                                                

PORTIBM PC Portable (uses same BIOS as XT) 0140-014F - Future Domain TMC-16x0 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:	alternate address at 0150, 0160, 0170
Notes:	TMC-1650/1670 have a 25-pin external connector, whereas the 1660 and
	  1680 have a SCSI-2 50-pin high-density external connector
	TMC-1670/1680 have floppy disk controller built in
	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. versions prior to 3.2 assigned 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 6 to 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,
	  versions 3.2 and greater use 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 7
	the drive ordering implemented in 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. versions 3.4 and 3.5 is the
	  opposite of the order (currently) used by the rest of 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.
	  industry--for example, under DOS 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 0 will be D: and 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 1
	  will be C:
	Future Domain TMC-16x0 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 series are based upon Future Domain
	  TMC-1800/18C50/18C30 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
	TMC-1800/18C50/18C30 are 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. controllers, TMC-36C70 is a PCI
	  version of TMC-18C30
	TMC-1800/18C50 have 8K FIFO, TMC-18C30/36C70 have 2K FIFO
	Future Domain TMC-1650/1660/1670/1680/1610M/1610MER/1610MEX 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.
	  adapters are based on TMC-1800/18C50/18C30
	Quantum ISA-200S/250MG 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. adapters are based on TMC-18C50 (?)
	Future Domain TMC-3260 and 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. adapters are
	  based on TMC-36C70

0140  R-  read 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 register
0140  -W  write 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 register
0141  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 (see #P0501)
0141  -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 register (see #P0502)
0142  R-  TMC status register (see #P0503)
0142  -W  interrupt control register (see #P0504)
0143  R-  FIFO status register, TMC-18C50/18C30/36C70 chips only
0143  -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. mode control register (see #P0505)
0144  R-  interrupt condition register, TMC-18C50/18C30/36C70 only (see #P0506)
0144  -W  TMC control register (see #P0507)
0145  R-  ID code LSB register
	  27h for TMC-1800 chip
	  E9h for TMC-18C50/18C30/36C70 chips
0145  -W  memory control register, TMC-18C50/18C30/36C70 only
0146  R-  ID code MSB register
	  60h for TMC-18C50/18C30 chips
	  61h for TMC-1800 chip
0147  R-  read loopback register
0147  -W  write loopback register
0148  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 no ACK register
0149  R-  interrupt status register (see #P0508)
014A  R-  configuration register 1 (see #P0509)
014B  R-  configuration register 2, TMC-18C50/18C30/36C70 only (see #P0510)
014B  -W  I/O control register, TMC-18C30/36C70 only (see #P0511)
014Cw R-  read FIFO data register
014Cw -W  write FIFO data register
014Ew R-  FIFO data count register
Notes:	any value written into the write loopback register can be read back
	  from the read loopback register unchanged (this is used by the 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.
	  to test the controller)
	reading from read 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 register and writing to write 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
	  register causes REQ/ACK handshake to occur automatically, reading
	  and writing 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. data no ACK register doesn't
	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 may be used only for DATA IN / DATA OUT phase transfers on
	  TMC-1800; on TMC-18C50/18C30 it may also be used for COMMAND phase
	  transfers


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. status register:
Bit(s)	Description	(Table P0501)
 7	not BSY
 6	not MSG
 5	not I/O
 4	not C/D
 3	not REQ
 2	not SEL
 1	parity error???
 0	not ATN
SeeAlso: #P0502,#P0511


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. control register:
Bit(s)	Description	(Table P0502)
 7	RST
 6	SEL
 5	BSY
 4	ATN
 3	I/O
 2	C/D
 1	MSG
 0	bus enable
SeeAlso: #P0501,#P0503,#P0504


Bitfields for TMC status register:
Bit(s)	Description	(Table P0503)
 7	bus enabled
 6	parity enabled
 5	FIFO enabled
 4	=1 data are expected to flow out from FIFO to 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
	=0 data are expected to flow from 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 into FIFO
 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. reset
 2	???
 1	arbitration complete
 0	interrupt request
SeeAlso: #P0502


Bitfields for interrupt control register:
Bit(s)	Description	(Table P0504)
 7	enable interrupt on REQ
 6	enable interrupt on SEL
 5	enable arbitration interrupt
 4	enable interrupt on ???
 0-3	FIFO threshold (how many 512 byte blocks in FIFO should be
	  full/empty for interrupt to be generated)
SeeAlso: #P0502


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. mode control register:
Bit(s)	Description	(Table P0505)
 7	synchronous mode
 6	fast 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.
 5-4	reserved?
 3-0	synchronous transfer period in 25 ns units
SeeAlso: #P0502


Bitfields for interrupt condition register:
Bit(s)	Description	(Table P0506)
 7	FIFO error interrupt
 6	forced interrupt???
 5	interrupt on RST
 4	arbitration interrupt
 3	interrupt on SEL
 2	interrupt on REQ
 1	interrupt on ???
 0	???
SeeAlso: #P0502


Bitfields for TMC control register:
Bit(s)	Description	(Table P0507)
 7	enable FIFO
 6	=1 data are expected to flow out from FIFO to 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
	=0 data are expected to flow from 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 into FIFO
 5	clear forced interrupt, TMC-18C50/18C30/36C70 only
 4	enable interrupt
 3	enable parity
 2	arbitrate
 1	force interrupt???
 0	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. reset flag???
SeeAlso: #P0502
Note:	on the TMC-1800 the FIFO must be enabled and bit 6 must be set
	  according to the expected data direction before a data phase will
	  occur (the TMC-1800 probably doesn't generate interrupts on REQ in
	  DATA IN / DATA OUT phases); on the TMC-18C50/18C30 it may be done
	  when the interrupt on REQ occurs and 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. phase is
	  DATA IN, DATA OUT or COMMAND


Bitfields for interrupt status register:
Bit(s)	Description	(Table P0508)
 7	interrupt on REQ enabled
 6	interrupt on SEL enabled
 5	arbitration interrupt enabled
 4	interrupt on ??? enabled
 3	interrupt enabled
 2	???
 1	always set???
 0	???
SeeAlso: #P0502


Bitfields for configuration register 1:
Bit(s)	Description	(Table P0509)
 7-6	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. address range
	00 C8000h-C9FFFh
	01 CA000h-CBFFFh
	10 CE000h-CFFFFh
	11 DE000h-DFFFFh
 5-4	I/O address range
	00 140h-14Fh
	01 150h-15Fh
	10 160h-16Fh
	11 170h-17Fh
 3-1	interrupt select
	000 IRQ3
	001 IRQ5
	010 IRQ10
	011 IRQ11
	100 IRQ12
	101 IRQ14
	110 IRQ15
	111 no IRQ(Interrupt ReQuest) A hardware line connected to the interrupt controller chip which signals that a CPU interrupt should be generated.
 0	reserved???
Note:	the seven on-board configuration jumpers are read through this register
SeeAlso: #P0502,#P0510


Bitfields for configuration register 2:
Bit(s)	Description	(Table P0510)
 7	32-bit mode enabled (TMC-18C30/36C70 only???)
 6-2	???
 1	RAM(Random Access Memory)	See also DRAM, SRAM. disabled (TMC-18C30/36C70 only???)
 0	???
Note:	256 byte on-chip RAM(Random Access Memory)	See also DRAM, SRAM. is mapped at offset 1F00h within the 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. segment
SeeAlso: #P0502,#P0509


Bitfields for TMC control register:
Bit(s)	Description	(Table P0511)
 7	enable 32-bit mode
 6-0	???
SeeAlso: #P0502