Legacy Document

Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Slot Manager Routines / Getting Information About Expansion Cards and Declaration ROMs

SReadFHeader

You can use the SReadFHeader function to obtain a copy of the information in the format block of a declaration ROM.

FUNCTION SReadFHeader (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

-->	spResult	Pointer	A pointer to an FHeaderRec data structure (described on page 2-26).
-->	spSlot	SignedByte	The slot number.
X	spsPointer	Ptr
X	spSize	LongInt
X	spOffsetData	LongInt
X	spByteLanes	SignedByte

DESCRIPTION

The SReadFHeader function copies the information from the format block of the expansion card in the requested slot to an FHeaderRec data structure you provide.

You specify the slot with the spSlot parameter. You must also allocate an FHeaderRec data structure and provide a pointer to it in the spResult field.

The SReadInfo function copies the information in the format block into the data structure pointed to by the spResult field.

SPECIAL CONSIDERATIONS

This function may alter the contents of the spsPointer, spSize, spOffsetData, and spByteLanes fields. Your application should not depend on the values returned in these fields.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SReadFHeader function are

Trap macro	Selector
_SlotManager	$0013

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	$0013

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smEmptySlot	-300	No card in this slot

SEE ALSO

For general information about the format block, see "The Format Block," beginning on page 2-13. For information about the fields of the format block, see Designing Cards and Drivers for the Macintosh Family, third edition.