Technical data

Attach one of the following cables to a connector on the breakout cable if
you require longer cable lengths: BC22F-10, BC22F-25, or BC22F-50. The
peripheral you are using may require a null-modem extension cable. See
the peripheral documentation or contact your Digital Sales representative
for information on the correct null-modem cable to use.
• DSSI hard disk drives, including the RF31T, the RF35, and the RF36.
• SCSI storage devices, including the following removable devices:
– TLZ06 tape drive
– TZK10 (QIC) tape drive
– TZ30 tape drive
– RRD42 compact disc drive
• Digital Storage Systems Interconnect (DSSI)– The KA52 CPU module
contains one DSSI bus connector that is dedicated to the mass storage
devices in your system.
A DSSI connector provides a path to the DSSI bus through which the CPU
can communicate with DSSI devices.
The DSSI bus has the following characteristics.
– A 4-Mbytes-per-second bandwidth
– Up to eight nodes (one interface and up to seven additional DSSI
Devices (RF-series ISEs, TF85s, and adapters))
– Eight data lines
– One parity line
– Eight control lines
DSSI architecture improves system performance as follows.
– Each device queues requests and each performs seek ordering.
– Mass storage devices can act independently, since each device contains
its own controller. Several devices can work simultaneously.
An ISE can maintain connection to more than one DSSI interface. That feature
allows ISEs to be shared by multiple CPUs in a DSSI VAXcluster configuration.
For more information about DSSI VAXcluster configurations and the
advantages of such configurations, see the section on DSSI VAXcluster
capability in your system Operation manual.
Hardware Options 4–3