Legacy Document

Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Low-Level Routines /

SReadPBSize

This function is used only by the Macintosh Operating System.

FUNCTION SReadPBSize (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).
<--	spSize	LongInt	The size of the sBlock data structure.
-->	spID	SignedByte	The ID of the sBlock in the sResource.
<--	spByteLanes	SignedByte	The byte lanes from the card's format block.
-->	spFlags	SignedByte	Flags.

DESCRIPTION

The SReadPBSize function returns the size of an sBlock data structure.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SReadPBSize function are

Trap macro	Selector
_SlotManager	$0026

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	$00026

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smNoMoresRsrcs	-344	Requested sResource not found

SEE ALSO

For more information about the high-level routine for obtaining information from an sBlock data structure, see the description of the SGetBlock function on page 2-47.