PORTIBM PC Portable (uses same BIOS as XT) 0340-035F - Adaptec AHA-152x 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 0140 Note: Adaptec AHA-152x 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 Adaptec AIC-6260/6360/6370 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) xxxxh"Adaptec AIC-78xx" +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 #P0601) +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 #P0602) +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 #P0605) +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 #P0606) +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 register (SCSIDAT) read/write causes -ACK to pulse +007 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. data bus register (SCSIBUS) +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 #P0608) +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 #P0611) +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) +00E ?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. test control register (SCSITEST) (see #P0613) +00F 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 4 (SSTAT4) (see #P0614) +00F -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 4 (CLRSINT4) (see #P0615) +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 DMAsee Direct Memory Access control register 0 (DMACNTRL0) (see #P0618) +013 RW DMAsee Direct Memory Access control register 1 (DMACNTRL1) (see #P0619) +014 RW DMAsee Direct Memory Access status register (DMASTAT) (see #P0620) +015 RW FIFO status register (FIFOSTAT) +016w RW data port register (DATAPORT) +018 RW burst control register (BRSTCNTRL) (see #P0621) +01A RW port A register (PORTA) (see #P0622) +01B RW port B register (PORTB) (see #P0623) +01C RW revision register (REV) +01D RW stack register (STACK) +01E RW test register (TEST) (see #P0624) +01F R? (AIC-6360+) ID register (ID) 32-byte ID string can be read here 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. latched data register is used to transfer data 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 during automatic or manual PIO mode 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 bus register reflects the state of 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 lines directly 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. sequence control register (SCSISEQ): Bit(s) Description (Table P0600) 7 enable target mode (TEMODEO) 6 enable selection out (ENSELO) 5 enable selection in (ENSELI) 4 enable reselection in (ENRESELI) 3 "ENAUTOATNO" 2 "ENAUTOATNI" 1 enable auto -ATN on parity error (ENAUTOATNP) 0 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 out (SCSIRSTO) Note: each bit when set starts a specific 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 on the bus SeeAlso: #P0602,#P0607,#P0608,#P0616 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. transfer control register 0 (SXFRCTL0): Bit(s) Description (Table P0601) 7 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 enable (SCSIEN) 6 DMAsee Direct Memory Access FIFO enable (DMAEN) 5 channel enable (CHEN) 4 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. transfer counter (CLRSTCNT) 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. PIO enable (SPIOEN) 2 SCAM enable (SCAMEN) 1 clear channel (CLRCH) 0 reserved SeeAlso: #P0602,#P0607,#P0611,#P0618,#P0620 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. transfer control register 1 (SXFRCTL1): Bit(s) Description (Table P0602) 7 bit bucket (BITBUCKET) 6 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. counter wrap enable (SWRAPEN) 5 enable 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 check (ENSPCHK) 4-3 selection time-out select (STIMESEL) 00 256 ms 01 128 ms 10 64 ms 11 32 ms 2 enable selection timer (ENSTIMER) 1 byte align (BYTEALIGN) 0 reserved SeeAlso: #P0600,#P0601 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 signal read register (SCSISIGI): Bit(s) Description (Table P0603) 7 -C/D input (CDI) 6 -I/O input (IOI) 5 -MSG input (MSGI) 4 -ATN input (ATNI) 3 -SEL input (SELI) 2 -BSY input (BSYI) 1 -REQ input (REQI) 0 -ACK input (ACKI) Note: this register reflects the actual state 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. bus control lines SeeAlso: #P0604 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 signal write register (SCSISIGO): Bit(s) Description (Table P0604) 7 -C/D output (CDO) 6 -I/O output (IOO) 5 -MSG output (MSGO) 4 -ATN output (ATNO) 3 -SEL output (SELO) 2 -BSY output (BSYO) 1 -REQ output (REQO) 0 -ACK output (ACKO) Notes: writing to this register modifies the control signals on the bus; only those signals that are allowed in the current mode (initiator/target) are asserted bits 7-5 in initiator mode represent the expected 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 phase and can be used to trigger phase mismatch and phase change interrupts SeeAlso: #P0603 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. rate control register (SCSIRATE): Bit(s) Description (Table P0605) 7 reserved 6-4 synchronous transfer rate (SXFR) rate = 100 + SXFR * 25 (ns) 3-0 synchronous offset (SOFS) Note: contents of this register determine the synchronous 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 transfer rate and the maximum synchronous -REQ/-ACK offset; an offset of 0 in the bits 3-0 disables synchronous data transfers, any offset value greater than 0 enables snchronous transfers SeeAlso: #P0611 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. ID register (SCSIID): Bit(s) Description (Table P0606) 7 reserved 6-4 our ID (OID) 3 reserved 2-0 target ID (TID) Note: this register contains 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. ID of the board and the current target on the selected channel SeeAlso: #P0982 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 0 (SSTAT0): Bit(s) Description (Table P0607) 7 target mode (TARGET) 6 selection out done (SELDO) 5 selection in done (SELDI) 4 selection in progress (SELINGO) 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. counter wrap (SWRAP) 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. PIO done (SDONE) 1 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. PIO ready (SPIORDY) 0 DMAsee Direct Memory Access done (DMADONE) Note: bits 1-0 and 6-4 are self-clearing bit 2 is set when 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. transfer count register decrements to 0 SeeAlso: #P0600,#P0601,#P0608,#P0616 Bitfields for 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): Bit(s) Description (Table P0608) 7 set 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. PIO done? (SETSDONE) 6 clear selection out done (CLRSELDO) 5 clear selection in done (CLRSELDI) 4 clear selection in progress (CLRSELINGO) 3 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. counter wrap (CLRSWRAP) 2 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. PIO done (CLRSDONE) 1 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. PIO ready (CLRSPIORDY) 0 reserved Note: writing 1 to a bit clears the associated 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; writing 1 to the bits 3-2 also clears the asscoiated bits in SSTAT0 SeeAlso: #P0600,#P0601,#P0607,#P0616 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 1 (SSTAT1): Bit(s) Description (Table P0609) 7 selection time-out (SELTO) 6 (target) "ATNTARG" 5 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 in (SCSIRSTI) 4 phase mismatch (PHASEMIS) 3 bus free (BUSFREE) 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. parity error (SCSIPERR) 1 phase changed (PHASECHG) 0 -REQ asserted (REQINIT) Notes: bit 0 can be cleared by setting bit 0 in the 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 1 register (CLRSINT1), and by asserting -ACK as well bit 4 is self-clearing SeeAlso: #P0602,#P0603,#P0604,#P0610,#P0617 Bitfields for 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): Bit(s) Description (Table P0610) 7 clear selection time-out (CLRSELTIMEO) 6 clear -ATN output (CLRATNO) 5 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 in (CLRSCSIRSTI) 4 reserved 3 clear bus free (CLRBUSFREE) 2 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. parity error (CLRSCSIPERR) 1 clear phase changed (CLRPHASECHG) 0 clear -REQ asserted (CLRREQINIT) Note: writing 1 to a bit clears the associated 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; writing 1 to the bits 3-0, 5, and 7 also clears the associated bits in SSTAT1 SeeAlso: #P0603,#P0604,#P0609,#P0617 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 2 (SSTAT2): Bit(s) Description (Table P0611) 7-6 reserved 5 "SOFFSET" 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. FIFO empty (SEMPTY) 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. FIFO full (SFULL) 2-0 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 count (SFCNT) Note: 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. FIFO is 8 bytes long; bit 3 is set when all the 8 bytes are full (bits 2-0 are clear) SeeAlso: #P0601,#P0605,#P0614,#P0615 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 3 (SSTAT3): Bit(s) Description (Table P0612) 7-4 "SCSICNT" 3-0 "OFFCNT" SeeAlso: #P0605,#P0611 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. test control register (SCSITEST): Bit(s) Description (Table P0613) 7-4 reserved 3 "SCTESTU" 2 "SCTESTD" 1 reserved 0 "STCTEST" SeeAlso: #P0624 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 4 (SSTAT4): Bit(s) Description (Table P0614) 7-3 reserved 2 "SYNCERR" 1 FIFO write error? (FWERR) 0 FIFO read error? (FRERR) SeeAlso: #P0611,#P0615 Bitfields for 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 4 (CLRSINT4): Bit(s) Description (Table P0615) 7-3 reserved 2 "CLRSYNCERR" 1 clear FIFO write error? (CLRFWERR) 0 clear FIFO read error? (CLRFRERR) SeeAlso: #P0611,#P0614 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. interrupt mode register 0 (SIMODE0): Bit(s) Description (Table P0616) 7 reserved 6 enable selection out done (ENSELDO) 5 enable selection in done (ENSELDI) 4 enable selection in progress (ENSELINGO) 3 enable 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. counter wrap (ENSWRAP) 2 enable 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. PIO done (ENSDONE) 1 enable 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. PIO ready (ENSPIORDY) 0 enable DMAsee Direct Memory Access done (ENDMADONE) Note: setting any bit will enable the corresponding function to interrupt via the IRQ(Interrupt ReQuest) A hardware line connected to the interrupt controller chip which signals that a CPU interrupt should be generated. pin SeeAlso: #P0607,#P0608,#P0617,#P0618 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. interrupt mode register 1 (SIMODE1): Bit(s) Description (Table P0617) 7 enable selection time-out (ENSELTIMO) 6 (target) "ENATNTARG" 5 enable 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 (ENSCSIRST) 4 enable phase mismatch (ENPHASEMIS) 3 enable bus free (ENBUSFREE) 2 enable 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 error (ENSCSIPERR) 1 enable phase changed (ENPHASECHG) 0 enable -REQ asserted (ENREQINIT) Note: setting a bit enables the corresponding function to interrupt via the IRQ(Interrupt ReQuest) A hardware line connected to the interrupt controller chip which signals that a CPU interrupt should be generated. pin SeeAlso: #P0609,#P0610,#P0616 Bitfields for DMAsee Direct Memory Access control register 0 (DMACNTRL0): Bit(s) Description (Table P0618) 7 enable DMAsee Direct Memory Access (ENDMA) 6 =0 16-bit mode =1 8-bit mode (8BIT) 5 =0 PIO mode =1 DMAsee Direct Memory Access mode 4 double word PIO (DWORDPIO) 3 =0 read =1 write 2 interrupt enable (INTEN) 1 reset FIFO (RSTFIFO) 0 software interrupt (SWINT) Note: write to this register takes the controller from the power down mode SeeAlso: #P0601 Bitfields for DMAsee Direct Memory Access control register 1 (DMACNTRL1): Bit(s) Description (Table P0619) 7 power down (PWRDWN) 6 "ENSTK32" 5 reserved 4-0 stack pointer? (STK) Bitfields for DMAsee Direct Memory Access status register (DMASTAT): Bit(s) Description (Table P0620) 7 "ATDONE" 6 word ready (WORDRDY) 5 interrupt status (INTSTAT) 4 DMAsee Direct Memory Access FIFO full (DFIFOFULL) 3 DMAsee Direct Memory Access FIFO empty (DFIFOEMP) 2 (AIC-6360+?) DMAsee Direct Memory Access FIFO half-full? (DFIFOHF) 1 (AIC-6360+?) double word ready (DWORDRDY) 0 reserved SeeAlso: #P0601,#P0618 Bitfields for burst control register (BRSTCNTRL): Bit(s) Description (Table P0621) 7-4 bus on time (BON) 3-0 bus off time (BOFF) Note: the bus on/off times are in microseconds SeeAlso: #P0624 Bitfields for port A register (PORTA): Bit(s) Description (Table P0622) 7 transfer mode =0 PIO =1 DMAsee Direct Memory Access 6 boot enabled (BOOT) 5-4 message classes (MSGCLASSES) 00 #4 01 #0, #1, #2, #3, #4 10 #0, #3, #4 11 #0, #4 3 initial synchronous negotiation enabled (SYNCNEG) 2 target disconnect enabled (TARDISC) 1-0 reserved SeeAlso: #P0623 Bitfields for port B register (PORTB): Bit(s) Description (Table P0623) 7 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 enabled (PARITY) 6-5 DMAsee Direct Memory Access channel (DMACHAN) 00 DMAsee Direct Memory Access channel 0 01 DMAsee Direct Memory Access channel 5 10 DMAsee Direct Memory Access channel 6 11 DMAsee Direct Memory Access channel 7 4-3 "IRQ(Interrupt ReQuest) A hardware line connected to the interrupt controller chip which signals that a CPU interrupt should be generated." 00,11 IRQ12 01 IRQ10 10 IRQ11 2-0 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 SeeAlso: #P0622 Bitfields for test register (TEST): Bit(s) Description (Table P0624) 7 reserved 6 bus off timer test (BOFFTMR) 5 bus on timer test (BONTMR) 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. transfer count register high byte test (STCNTH) 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. transfer count register middle byte test (STCNTM) 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. transfer count register low byte test (STCNTL) 1 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 test (SCSIBLK) 0 DMAsee Direct Memory Access block test (DMABLK) SeeAlso: #P0613,#P0621