RL01/RL02 Disk Subsystem

This manual serves as a comprehensive guide for the Digital RL01/RL02 Disk Subsystem, covering its capabilities, installation, operation, and programming. The subsystem primarily consists of RL01/RL02 disk drives and one of three controllers: the RL11 (for PDP-11 Unibus), RLV11 (for LSI-11 Q-Bus), or RL8A (for PDP-8 Omnibus). Up to four drives can be managed by a single controller.

The document details the physical and environmental specifications for the disk drives and their removable RL01K/RL02K disk cartridges. The RL01K offers 5.2 megabytes, and the RL02K offers 10.4 megabytes of user data, formatted into 40 sectors of 256 bytes each. Key information such as servo and header data is prerecorded and protected from user overwrite. Although physically interchangeable, RL01K and RL02K cartridges are not functionally interchangeable on the wrong drive type.

Installation procedures include site preparation (considering environmental factors like cleanliness, temperature, humidity, and EMI), AC power requirements, grounding, and detailed steps for installing each controller type (RL11, RLV11, RL8A) and the disk drives themselves. Confidence testing using diagnostic programs is also covered.

An operator's guide explains the controls and indicators (Power On/Off, Run/Stop, Unit Select, Fault, Write Protect) and provides operating procedures for loading and unloading cartridges and starting up/shutting down the drives. User maintenance is limited to external cleaning of cartridges and spindle assemblies.

Extensive programming information is provided for the RL11/RLV11 and RL8A controllers, detailing addressable registers (Control Status, Bus Address, Disk Address, Multipurpose, Error) and commands (No-Op, Write Check, Get Status, Seek, Read Header, Write Data, Read Data Without Header Check). Operational considerations, including interrupt handling, seek operations, data transfer, and error recovery, are discussed. The manual also highlights key differences between programming the RL01/RL02 subsystem and the older RK05 disk cartridge subsystem, noting that RL01/RL02 requires more software control for functions like spiral read/write, implicit seeks, and recalibration.