Apple DVD Studio Pro 4 - Manual (Page 513)

About SPRMs and Partitioned GPRMs
SPRMs fall into one of three categories:
• Those that use the first bits of their register, such as SPRM 1
• Those that use part of the register, but not the first bits, such as SPRM 14 which uses
bits 8 through 11
• Those that use the entire register, with each bit representing the status of a function,
such as SPRM 15
If you partition a GPRM into four 4-bit registers, then move the same SPRM value into
each register, each of the 4-bit registers would get the same first four bits of the SPRM.
As an example, while SPRM 14 only uses four bits of its register, because they are not
the first four bits, they cannot be moved into a partitioned GPRM register. For this reason,
it is recommended that you always keep several 16-bit GPRMs available.
Configuring GPRM Partitions
You are able to individually configure the partitions of each 16-bit GPRM register using
either the Script Inspector or the Advanced tab of the Disc Inspector. Once configured,
you are then able to name them and save the configuration, which can then be loaded
into a different project.
Important: Once you partition a GPRM register and use it in a script, you cannot change
the GPRM’s partition settings. You also cannot import a script’s item description unless
the GPRMs it uses are partitioned the same as when the item description was saved.
To configure a GPRM’s partition
1 Do one of the following:
• Select a script in the Outline or Graphical tab. The Script Inspector appears.
• Select the disc in the Outline tab, then click the Advanced tab in the Disc Inspector.
• Click an empty area in the Graphical tab, then click the Advanced tab in the Disc
Inspector.
513 Chapter 20 Creating Scripts