Legacy Document

Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Low-Level Routines /

SCalcSPointer

This function is used only by the Macintosh Operating System.

FUNCTION SCalcSPointer (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

<-->	spsPointer	Ptr	A pointer to a byte in declaration ROM.
-->	spOffsetData	LongInt	The offset in bytes to desired pointer.
-->	spByteLanes	SignedByte	The byte lanes used.

DESCRIPTION

The SCalcSPointer function returns a pointer to a given byte in the declaration ROM of an expansion card.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SCalcSPointer function are

Trap macro	Selector
_SlotManager	$002C

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	$002C

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smNoMoresRsrcs	-344	Requested sResource not found