1.2.2.3 Mass Storage Expanders
You can expand the mass storage and Q–bus capacity of your system by using the
following expanders.
• The R400X mass storage expander contains seven ISE bays. Each bay can
hold one single-disk storage device or one single dual-disk storage device. The
top right ISE bay can hold a tape drive or a disk drive.
The R400X can be configured such that all disks are either on the same bus
or the top and bottom rows are split into two separate buses.
Table 1–2 R400X Expansion
Number of
Single Bus
Boxes
Number of
Split Bus
Boxes
Total
Buses
Number of
Maximum Devices
1
–
1
7
–
1
2
13 (7 top row bus, 6 bottom row bus)
2
–
2
14 (7 per box)
–
2
4
26 (13 per box)
1
1
3
20 (13 split bus box)
(7 single bus box)
The BA440 box that contains the CPU module may have up to six DSSI
adapters (four CPU-native and two KFQSAs). These may be connected to up
to six separate external DSSI buses. When connecting to the BA440 box’s
DSSI bus 0, make sure of the following:
There are only seven devices on the bus.
No external device node numbers conflict with any BA440 bus 0 device
node numbers.
Note
One of the eight nodes on a DSSI bus must be a DSSI CPU adapter.
1–24 System Overview
