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Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Low-Level Routines /

SOffsetData

This function is used only by the Macintosh Operating System.

FUNCTION SOffsetData (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

<-->	spsPointer	Ptr	On output: A pointer to the sResource entry.
<--	spOffsetData	LongInt	The contents of the offset field.
-->	spID	SignedByte	The ID of the sResource entry.
<--	spByteLanes	SignedByte	The byte lanes from the card's format block.

DESCRIPTION

The SOffsetData function returns the value of the offset field of an sResource entry.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SOffsetData function are

Trap macro	Selector
_SlotManager	$0024

On entry, register D0 contains the routine selector and register A0 contains 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	$0024

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smNoMoresRsrcs	-344	Requested sResource not found

SEE ALSO

For information about high-level routines for getting information from sResources, see the descriptions of the SReadByte, SReadWord, SReadLong, SGetCString, SGetBlock, SReadStruct, and SFindStruct functions in "Getting Information From sResources," beginning on page 2-40.