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Functional Description

SCSI Interface

The MVME177 provides for mass storage subsystems through the industry-standard SCSI bus. These subsystems may include:

Hard and floppy disk drives

Streaming tape drives

Other mass storage devices

The SCSI interface is implemented using the NCR 53C710 SCSI I/O controller.

The SCSI clock input to the 53C710 is fixed at 50 MHz, in order to have higher SCSI bus performance, and to make it easier for software to program the 53C710 controller when the MC68060 processor speed changes.

Support functions for the 53C710 are provided by the PCCchip2. Refer to the 53C710 user's guide and to the Single Board Computers Programmer's Reference Guide for detailed programming information.

SCSI Termination

The system configurer must ensure that the SCSI bus is properly terminated at both ends. On the MVME177, sockets are provided for the terminators on the P2 transition board. If the SCSI bus ends at the P2 transition board, then termination resistors must be installed on the P2 transition board. +5V power to the SCSI bus TERM power line and termination resistors is provided through a fuse on the MVME712 transition board, and a diode located on the P2 transition board.

Local Resources

The MVME177 includes many resources for the local processor. These include:

Tick timers

Software programmable hardware interrupts

Watchdog timer

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Motorola MVME177 manual Local Resources, Scsi Interface, Scsi Termination