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Important: The information in this document is obsolete and should not be used for new development.

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Inside Macintosh: Devices /
Chapter 2 - Slot Manager / Slot Manager Reference
Low-Level Routines /


SCalcStep

This function is used only by the Macintosh Operating System.

FUNCTION SCalcStep (spBlkPtr: SpBlockPtr): OSErr;
spBlkPtr
A pointer to a Slot Manager parameter block.
<--spResultLongIntThe function result.
-->spsPointerPtrA pointer to a byte in declaration ROM.
-->spByteLanesSignedByteThe byte lanes used.
-->spFlagsSignedByteFlags.

DESCRIPTION
The SCalcStep function calculates the field sizes in the block pointed to by spBlkPtr. It is used for stepping through the card firmware one field at a time. If the fConsecBytes flag is set the function calculates the step value for consecutive bytes; otherwise it calculates it for consecutive IDs.

ASSEMBLY-LANGUAGE INFORMATION
The trap macro and routine selector for the SCalcStep function are
Trap macroSelector
_SlotManager$0028

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
A0Address of the parameter block
D0$0028
Registers on exit
D0Result code

RESULT CODES
noErr0No error
smNoMoresRsrcs-344Requested sResource not found

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© Apple Computer, Inc.
3 JUL 1996