Specifications

TURBOchannel Bus Support
12.3 TURBOchannel on DEC 3000 Model 400
Figure 12–13 DEC 3000 Model 400 ADP List
DEC 3000 Model 400 ADP List
IOC$GL_ADPLIST
adp$ps_child_adp
adp$1_crab
adp$ps_child_adp
adp$ps_peer_adp
System ADP
Turbo ADP
TR = 2
TR = 1
type = AT$_TC
CRAB
Used to manage
type = AT$_KA0402
Scatter/Gather entries.
header
Note: the TurboSCSI
9
entries
header
ADP and the Core ADP
2
entries
SCSI Port A
header
Entry 3 − 5 user
4
SCSI Port B
entries
also contain pointers
Lance
Serial Line 0
TC slots
Serial Line 1
TurboSCSI
Bus Array
ISDN
TurboSCSI ADP
TR = 3
type = AT$_TURBO_SCSI
Entry 6 Integrated
Core
Bus Array
to the CRAB.
SCSI adapter
Core ADP
TR = 4
type = AT$_COREIO
Entry 7 CoreIO
Subsystem
Entry 8
empty
Turbo
Bus Array
ZK−6724A−GE
Entry 0 − 2
empty
Dense and sparse space addressing, register access, DMA and Scatter/Gather
map management, bus interface registers, and device configuration are all
treated exactly the same on DEC 3000 Model 400 as on DEC 3000 Model 500.
IOC$NODE_DATA and IOC$NODE_FUNCTION work identically on DEC 3000
Model 400 as on DEC 3000 Model 500.
12.4 TURBOchannel on DEC 3000 Model 300
The TURBOchannel on DEC 3000 Model 300 has some differences from the DEC
3000 Model 500/DEC 3000 Model 400 implementation. There are only two option
slots, and the address map is different. The Integrated SCSI adapter offers only
a single SCSI port. However, the most significant difference is the lack of a
Scatter/Gather map on DEC 3000 Model 300. All TURBOchannel DMA on DEC
3000 Model 300 must be physical DMA. The DMA burst size is limited to 64
longwords (compared to 128 longwords on DEC 3000 Model 500 and DEC 3000
Model 400). Also, DEC 3000 Model 300 does not support TURBOchannel parity.
Option modules that support parity checking should disable this feature on DEC
12–17