Commodore Amiga A500 - Page 173

40142 WRITE READ
*HCBP bit
not defined
not defined
not defined
not defined
Interrupt enable
DON'T .CARE
MUST BE ZERO
*CCBP bit
INT2 PENDING
ZERO
ZERO
INT FOLLOW
* Signals unique to Amiga Hard DisWSCSl Controller.
SSEL Used to select
SCSl controller or to ST605
controller. High = SCSI, low = ST506.
HCBP,CCBP
Host command block pointer and Controller
command block pointer. Used to handshake
address of Command block pointer to
ST506
48H Base address register
U0 addresses unique to 501-1
board
SCSI Controller
PROCC-Interrupt ST506 controller to process
command. Write only. Data value written from
host is
XXX1 hex.
WRCBPJINTACK - Multiplexed signal. WRCBP
strobes the command block pointer register.
IN-
TACK clear INTP at end of command.
CS
- Chip select for the WD33C93 SCSl chip.
Used to write to the internal address register and
read from the internal status register.
CS
- Chip select for the WD33C93 SCSl chip.
Used to write and read remaining Control regis-
ters in the
WD33C93.
SCSl PCSS - Used to initialize the 8727(DMA) in
SCSl mode. Refer to section 5.0 for 8727 com-
mands
SCSl PCSD
- Used to pas data to and from the
8727 in SCSl mode. Refer to section 5.0 for
transfer procedures.