RF11 disk controller

From Computer History Wiki
Revision as of 14:48, 14 April 2018 by Jnc (talk | contribs) (Add register list)
Jump to: navigation, search

The RF11 controller from DEC for the UNIBUS is an early secondary storage controller for the PDP-11. It can interface with up to eight RS11 fixed-head magnetic disk drives; each has a capacity of 512 Kbytes of storage.

Unlike all other DEC disk controllers, the RF11 can read or write individual words.

Like many of the early large peripheral controllers for the PDP-11, it was a large custom wire-wrapped backplane which bolted into the front of a 19 inch rack, such as an H960; into it plugged about 40 small M-Series FLIP CHIPs.

Device registers

Register Abbreviation Address
Disk Control Status Register DCS 777460
Word Count Register WC 777462
Current Memory Address CMA 777464
Disk Address Register DAR 777466
Disk Address Extension Error Register DAE 777470
Data Buffer Register DBR 777472
Maintenance Register MA 777474
Address of Disk Segment Register ADS 777476