DF10-C Data Channel

This document serves as a maintenance manual for the Digital Equipment Corporation DF10-C Data Channel, a high-speed (10^6 words per second) transfer device. It facilitates direct data transfers between the PDP-10 memory and various I/O devices like disks, drums, magnetic tapes, and real-time devices. The DF10-C functions as an I/O processor, independently handling data transfers once initiated by an I/O device.

The manual covers installation, operation, and maintenance procedures. Physically, the DF10-C is housed in a standard 19-inch DEC cabinet and includes power supplies and cooling systems. It can operate in either KA mode (using 18-bit control word addresses and word counts) or KI mode (using 14-bit word counts and 22-bit data addresses). Key internal logic sections include various control units and registers such as the Data Channel Control, Initial Address Register (CIA), Control Word Address Register (CCW), Data Address Register (CDA), and Word Count Register (WCR).

Operationally, the DF10-C is initiated by an I/O device supplying an initial control word address, which the channel then fetches and evaluates to determine the transfer operation. These control words can specify actions like terminating operations, jumping to a new control word address, skipping data without storing it, or performing normal data transfers. The channel uses various signals (e.g., CHANNEL START, CHANNEL BUSY, DEVICE PULSE) to communicate with devices and manage data flow. It supports block transfers of 36-bit words (256K in KA mode, 16K-1 in KI mode).

For maintenance and troubleshooting, the DF10-C features an indicator panel showing register contents and operational states, as well as several control switches. A crucial maintenance aid is the "Local Mode," which allows off-line testing by simulating a device, starting channel operations, loading control words, and generating device pulses internally, enabling single-stepping or automatic recycling for detailed observation. The manual also outlines preventive maintenance tasks and provides troubleshooting examples involving nonexistent memory tests and diagnosing faulty components based on observed operational errors.