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Inside Macintosh: Devices /

Chapter 3 - SCSI Manager / SCSI Manager Reference

SCSI Manager Routines /

SCSIRBlind

You can use the SCSIRBlind function to read data from a SCSI device using a blind transfer.

FUNCTION SCSIRBlind (tibPtr: Ptr): OSErr;

tibPtr

A pointer to an array of TIB instructions.

DESCRIPTION

The SCSIRBlind function is identical to the SCSIRead function but does not poll the SCSI controller before transferring each byte of data. The SCSI controller is polled only for the first byte transferred by each scInc, scNoInc, or scComp TIB instruction.

SPECIAL CONSIDERATIONS

You should use this function only if the device you are reading from is capable of transferring data fast enough to avoid timeout errors from the SCSI controller.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for SCSIRBlind are

Trap macro	Selector
_SCSIDispatch	$0008

RESULT CODES

noErr	0	No error
scCommErr	2	Communications error, operation timeout
scBadParmsErr	4	Unrecognized TIB instruction
scPhaseErr	X	Phase error on the SCSI bus
scCompareErr	6	Comparison error from scComp instruction
scBusTOErr	9	Bus timeout during blind transfer

SEE ALSO

See the description of the SCSIRead function on page 3-36 for information about performing a polled transfer. See "Choosing Polled or Blind Transfers," beginning on page 3-22, for additional information.