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Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Slot Manager Routines / Finding sResources

SNextSRsrc

You can use the SNextSRsrc function to step through the sResources on a card or from one card to the next.

FUNCTION SNextSRsrc (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

--	spsPointer	Ptr	A pointer to an sResource (described in "The sResource," beginning on page 2-7).
--	spIOReserved	Integer	The value of the slot resource table ioReserved field.
--	spRefNum	Integer	The driver reference number.
--	spCategory	Integer	The Category field of the sRsrcType entry (described on page 2-10).
--	spCType	Integer	The cType field of the sRsrcType entry.
--	spDrvrSW	Integer	The DrSW field of the sRsrcType entry.
--	spDrvrHW	Integer	The DrHW field of the sRsrcType entry.
-->	spSlot	SignedByte	The slot number.
-->	spId	SignedByte	The sResource ID.
-->	spExtDev	SignedByte	The external device identifier.
--	spHWDev	SignedByte	The hardware device identifier.

DESCRIPTION

The SNextSRsrc function is similar to the SRsrcInfo function, except the SNextSRsrc function returns information about the sResource that follows the requested one--that is, the one with the next entry in the sResource directory or the first sResource on the next card. The SNextSRsrc function skips disabled sResources.

You specify a particular sResource with the spSlot, spID, and spExtDev fields of the Slot Manager parameter block you point to in the spBlkPtr parameter. The SNextSRsrc function finds the next sResource, returns a pointer to it in the spsPointer field, and updates the spSlot, spID, and spExtDev fields to correspond to the sResource it found. If there are no more sResources, the SNextSRsrc function returns the smNoMoresRsrcs result code.

The SNextSRsrc function returns other information about the sResource in the spRefNum, spCategory, spCType, spDrvrSW, and spDrvrHW fields.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SNextSRsrc function are

Trap macro	Selector
_SlotManager	$0014

You must set up register D0 with the routine selector and register A0 with the address of the Slot Manager parameter block. When _SlotManager returns, register D0 contains the result code.

Registers on entry
A0	Address of the parameter block
D0	$0014

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smNoMoresRsrcs	-344	Requested sResource not found

SEE ALSO

For more control in finding sResources, you can use the SGetSRsrc function, described on page 2-33, and the SGetTypeSRsrc function, described on page 2-35.