Peripheral Subsystem Requirements

Hardware Design

____ 1.

Devices within peripheral subsystems shall not terminate the SCSI bus.

____ 2.

Provides two 50-conductor high-density SCSI connectors on the external device enclosure with visible SCSI icons near the connectors.

____ 3.

Supplies terminator power to the SCSI bus with a self resetting current limit device.

____ 4.

Provide labeled manual SCSI ID switches for use with non PnP master host connections. Note: This item is recommended for backward compatibility and is not a requirement for full PnP SCSI systems.

____ 5.

Ship with default SCSI ID per Table 1.


Software Design

____ 1.

Support SCAM level 1 slave protocol to request automatic SCSI ID assignment.

____ 2.

Support the full PnP SCSI command profile if and when defined (CD ROM definition in process)

____ 3.

Direct access devices return the actual number of user accessible logical blocks in response to the Read Capacity command.

____ 4.

All peripherals support Synchronous Negotiation protocol to avoid hanging the bus.

____ 5.

All peripherals support the SCSI INQUIRY command without significant delays.


Add-in Host Adapter Requirements

Hardware Design

____ 1.

ISA adapters are required to meet the PnP ISA specification.

1.1 Implement isolation circuit for unique card identification.

1.2 Identify resource requirements (IRQ, DMA, Memory and I/O space) in on board registers.

1.3 Provide software programmable resource options.

____ 2.

Use a 50-position high-density connector for external SCSI connections with a visible SCSI icon near the connector.

____ 3.

Supplies terminator power to the SCSI bus with a self resetting current limit device.

____ 4.

Supplies regulated termination:

4.1 For one end of the SCSI bus for internal only or external only SCSI chains.

4.2 Only if switchable terminator is at one end of the bus.


Software Design

____ 1.

Implement SCAM level 1 master protocol to automatically assign SCSI IDs.

____ 2.

Adapter option ROM requirements:

2.1 INT 13h BIOS extensions including logical block addressing for consistent geometry translation.

____ 3.

Implement PnP device drivers.