Technical information

2.2.1 KDA50 Controller

The KDA50 is an intelligent controller that interfaces with up to four SDI-

compatible mass storage devices on the Q22-bus.

Functional Information

Controller protocol MSCP

Bad block replacement Software dependent

Supported drives RA60, RA70, RA81, RA82, RA90, RA92

Drives per controller 4

Controllers per system 1 maximum for VMS 5.1

2 maximum for VMS V5.2 and later

Drive interconnect Transformer-coupled radial

Ordering Information

KDA50–SF RA-series disk drive controller, controls up to a

maximum of four RA-series devices

KDA50–SG Second KDA50 controller, for support of up to four

RA-series devices, uses three Q-bus slots

Performance

Read/Write data transfers Up to 16-byte block mode DMA

Data buffering 32 Kbytes

Command buffering 20 command and response ring buffers

Conﬁguration Information

Form factor Two quad height

Power requirements +5 Vdc, 13.5 A (typ); +12 Vdc, 0.03 A (typ)

Power consumption 67.86 W

Bus loads 3.0 ac; 0.5 dc