[jean-paul]

Uit de whitepaper van ROMCrafter (zie link hierboven).

Citaat:

PalmOS Memory Architecture
Applications and data can be stored in four distinct areas, on a PalmOS device, each with their own advantages and disadvantages. A PalmOS device has a different design
Brayder Technologies Inc. ROM Crafter™ philosophy than a typical computer. This reflected in how applications and data are stored and accessed.
The primary storage areas are RAM, System ROM and Expansion ROM. Each of these areas can store and allow direct access to applications and data. The fourth storage area is an expansion card. Expansion cards allow applications and data to be stored, but they typically require items to be moved to RAM before they can be directly accessed.

• RAM is where most add-on applications are stored and where all user-generated data is stored. The main feature of RAM is that items are directly modifiable by the PalmOS. The disadvantage of this storage area is that its contents will be lost if a battery failure or a hard reset should occur.
• System ROM is the storage area where the PalmOS itself is stored, along with all of the built-in applications. The main features of the System ROM are that contains the core operating system and its contents are not lost on a battery failure. The disadvantage of this storage area is that it is not normally modifiable. Items stored in the System ROM are not updateable.
• Expansion ROM is a new storage area supported by ROM Crafter. It uses the remaining area of the ROM that is not used by the System ROM. On devices that use Flash ROM, it can be used to store applications and databases. The contents of the Expansion ROM will not be lost if a battery failure or hard reset occurs. Files can be moved in and out of the Expansion ROM using the ROM Crafter libraries. The only disadvantage of this storage area is that it is not directly modifiable by the PalmOS. Modifiable items must be updated in RAM and then moved to the Expansion ROM.
• Expansion cards are used as a secondary storage area by the PalmOS. Files can be moved between RAM and an expansion card, and PalmOS applications can be modified to use expansion cards for data storage. The PalmOS Launcher provides a way of running applications from an expansion card by transparently copying it into RAM and then running it from there. The main advantage of expansion cards is their storage size; they can significantly add to the storage capabilities of a PalmOS device. The main disadvantage of expansion cards is that they work differently than the other storage areas and cannot be used transparently to expand the device. Another disadvantage of expansion cards is that they can be removed, eliminating any guarantee of availability.