01000010.gifP-ROM explained

Partial-Read Only Memory (P-ROM)

3.5-inch Magneto-Optical Disk

Fujitsu introduces the world's first, partial-read only memory (P-ROM) magneto-optical (MO) disk. The new disk contains both RAM (rewritable) and ROM (unrewritable) portions on the same media, so that application software can reside alongside rewritable memory. This feature significantly upgrades conventional optical disks, offering broader applications in such fields as desktop publishing, prepress, CAD/CAM, graphic arts, data analysis and data processing.

Applications software can be pre-stamped (the same as CD-ROM) on part of a disk, leaving the remaining capacity to be used for changing data. The media, having 128 megabytes of capacity, can contain operating systems and various kinds of applications software on the ROM portion and customised data on the RAM portion. The P-ROM allows the user to take his or her complete working environment wherever he or she goes, thereby changing the focus from the machine to the user. Used with Fujitsu's one-inch high 3.5-inch rewritable optical disk drive the M2511A and the M2512A the media offer several advantages over hard disks, including the removal and safe storage of important data.

Why P-ROM?

The advantages of using P-ROM are numerous. Since the ROM portion is physically processed, data and software recorded in this portion of the disk cannot be erased by laser beam or any accidental procedures. The RAM portion can contain additional software or user data which ca be altered by rewriting. The P-ROM can be used in compatible, fast-access-time and high-data-rate optical disk drives, offering much higher performance than conventional CD-ROMs. While having these advantages, the P-ROM is very economical. The cost of producing P-ROMs is reduced as production volume increases. When a stamping method is employed, the manufacturing cost is lower than copying data onto ordinary magneto-optical disks. Moreover, using P-ROM greatly reduces the risk of computer viruses because important data stamped on the ROM portion remains free from such infection.

How the P-ROM Is Used

01000004.gif Combines various applications software and RAM in one media

01000004.gif Provides large memory storage capacity and media removability.

Advanced Technologies

Fujitsu combines many precision technology into the P-ROM. A stamping method is used in the process of making P-ROMs. The P-ROM like conventional optical disks, is produced with grooves to maintain servo-mechanism stability. The structures of the RAM and ROM differ physically. The embossed pits in the ROM portion are created simultaneously with the grooves, thus requiring no additional processing time. Information is recorded via the thermo magnetic method and is read out utilising the magneto-optical Kerr effect. Information on the ROM portion if the disk is recorded in the same kind of embossed pits as on CDs. The read-out of this data takes place through the detection of the changes in the amount of light due to the presence of pits on the disk.

Now you can take along a large amount of data which is securely stored in a high-performance optical disk. When changes are required, you can add, delete, or revised information using the RAM portion of the disk.