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Inside Macintosh: Operating System Utilities /

Chapter 9 - Start Manager / Start Manager Reference

Routines / Identifying and Setting the Default Video Device

GetVideoDefault

You can use the GetVideoDefault procedure to return information that identifies the default video device.

PROCEDURE GetVideoDefault (paramBlock: DefVideoPtr);

paramBlock

A pointer to a default video device parameter block.

<--	sdSlot	SignedByte	Physical slot number.
<--	sdSResource	SignedByte	Slot resource ID (SResourceID).

DESCRIPTION

The GetVideoDefault procedure returns information from parameter RAM that identifies the default video device. If the sdSlot field returns a 0, indicating no default video device, the Start Manager chooses the first available video device when the computer starts up.

ASSEMBLY LANGUAGE INFORMATION

The registers on entry and exit for this routine are

Registers on entry
A0	Address of the default video device parameter block

Registers on exit
A0	Address of the default video device parameter block

SEE ALSO

For more information about the default startup device parameter block see "The Default Video Device Parameter Block" beginning on page 9-19.

To specify the default video device, see the description of the SetVideoDefault procedure described next.