Dreamcast Software Development Standards

Dreamcast Software Development Standards/Ver.1.00E

#### 17. Changing Discs for Multi-Disc Applications

17.1 Disc Switching Preconditions

> When performing a disc check to determine whether a disc is a "Special Dreamcast Disc," this version of Dreamcast does not require that the Main Unit Boot ROM Menu (the multi-player screen in Saturn) appear. However, because a soft reset might be needed when subsequent discs in a series are loaded, we believe that the Title Screen and Copyright Display may be needed.

> Also, the software creation standards of 15. Backup and other sections should always be followed unless specifically exempted.

17.2 Booting with Discs after the First

> Required: Other than the exceptions in 17.2.1,booting should comply with the conditions of 3. Sequences Before Game Start.

17.2.1 Exceptions for Booting from Discs after the First

> Demos

> Start/Option Selection Screen

> Options

> A Title Loop is not necessary if there is no Demo.

17.3 Soft Reset During Game Play

> Required: Except as stated in 17.3.1, a soft reset after starting a game must result in a jump to the Title Screen of the disc currently inserted in the Main Unit (e.g., a reset with Disc 3 installed results in display of the Disc 3 Title Screen).

> As described in 4.4 Soft Reset, executing a soft reset from the Title Loop of any disc brings up the Main Unit Boot ROM Menu (the Multi-Player screen in Saturn).

17.3.1 Soft Reset from the Disc Switching Screen

> Required: Executing a soft reset while switching discs (17.4 Switching Discs During Game Play) should result in a jump to the Main Unit Boot ROM Menu.

> Setting the soft reset jump destination to the Main Unit Boot ROM Menu allows the user to check the title and saved files on the menu if he inserts the wrong disc.

17.4 Switching Discs During Game Play (e.g., to Disc 2 when finished with Disc 1)

> Required: When switching discs, display a message such as, "Press the OPEN button to open the CD door and change the disc. After replacing Disc X with Disc Y, close the CD door."

> Required: After switching discs, always execute the Disc Check routine in the Boot ROM.

> Recommended: After switching discs, the game should resume without displaying boot sequence screens such as the Boot ROM menu, Logo or Title Screen.

> Recommended: It should be possible to switch discs from the Disc Switching Screen without having to go to the Boot ROM menu, even if the OPEN button is pressed when switching discs.

> After switching discs, a soft reset jumps to the Title Screen of the new disc, from which it is conceivable that the user could start the new disc's game. However, this is not recommended, and so should not be implemented.

> Recommended: The user should always be able to perform a save immediately before switching discs (or at least be provided a selectable Save command). For Autosave operation, execute an autosave before displaying the switching caution message.

> Considering the particular case where the user turns power off when switching discs, it should be possible to save data so that play can immediately continue when power is next turned on.

> Required: When switching discs, if the wrong disc is inserted, a message such as the following should appear: "This is not Disc X for [Application Name]. Press the OPEN button to open the CD door and replace the disc. After inserting Disc X, close the CD door."

> Required: At the start of a disc exchange sequence, the caution screens must be loaded into memory, so that after the user opens the tray and replaces the disc, even if the new disc is unreadable, the caution screens can be displayed correctly.

> Because the Main Unit Boot ROM Menu (Saturn's Multi-Player screen) is not executed when switching discs, if the correct disc does not load, the caution screens will not be available unless they have been stored in memory beforehand.

17.5 Loading From Multiple Discs (Loading Save Files for Different Discs)

> Required: When a save file is loaded for a disc other than the one currently inserted, a caution message must be displayed, such as "Press the OPEN button to open the CD door and replace the Disc. After inserting Disc X, close the CD door."

> Required: After switching discs, always execute the Disc Check routine in the Boot ROM.

> Required: When switching discs, if the wrong disc is inserted, a message such as the following should appear: "This is not Disc X for [Application Name]. Press the OPEN button to open the CD door and replace the disc. After inserting Disc X, close the CD door."

> Required: At the start of a disc exchange sequence, the caution screens must be loaded into memory, so that after the user opens the tray and replaces the disc, even if the new disc is unreadable, the caution screens can be displayed correctly.

Dreamcast Software Development Standards

Copyright SEGA ENTERPRISES, LTD, 1998