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The Super Virtual Disk Driver (SVDisk) provides a swappable/lockable/removable virtual disk or virtual floppy using OS/2's advanced memory management facility. Virtual disk can be anything from 16KB to 128MB, and virtual floppy supports 360KB to 2.88MB devices, including XDF device for managing XDF diskette images in OS/2 Warp Version 3. Virtual floppy device can be dynamically reconfigured. You can even create large SVDisks on a system with just 4MB of RAM! HPFS formatting and diskette support for SVDisk. Command line and PM utility provide complete control of the SVDisks.

Super Virtual Disk (SVDisk) is a 32-bit OS/2 device driver that emulates either a removable Virtual Disk (VDisk) or a removable Virtual Floppy (VFloppy) drive. By using OS/2's virtual memory management facility, SVDisk allows the entire contents of the disk to be swapped out via the paging mechanism. If the SVDisk is frequently accessed, OS/2 will keep the most recently used memory pages in RAM, and SVDisk will essentially behave like a RAM Disk.


  • Emulates multiple VDisk devices up to 16MB each even on a 4MB system. Cluster size is maintained at 512 bytes by varying the size of the File Allocation Table (FAT) to reduce file slack.
  • Emulates multiple VFloppy devices, ranging from 360KB to 2.88MB. Virtual media support ranges from 160KB to 1.2MB for 5.25" VFloppy device, and from 720K to 2.88MB for 3.5" VFloppy device. If the VFloppy is a 3.5" device, automatic media sensing is supported.
  • eXtended Density Format (XDF) support for OS/2 Warp V3 XDF diskette image files. This includes 1.52MB, 1.84MB and 3.68MB XDF diskettes. Utility is included to transfer XDF image file to and from XDF VFloppy.
  • Removable media support. This allows SVDisk to release all memory used by the device back to the system.
  • Dynamic device reconfiguration is supported for the VFloppy device. A VFloppy device can be reconfigured (without rebooting) to any other VFloppy drive or XDF drive.
  • HPFS formatting program for SVDisk. Mounting and unmounting of HPFS onto SVDisks are supported. HPFS diskette support (diskette imaging program such as Disk eXPress is required.)
  • Special boot sector on VFloppy device to allow bypassing of floppy boot if the image of the VFloppy is transferred to a real diskette using DISKCOPY.
  • Formatting and sector/track read/write are supported.
  • SVDisk allows locking of swappable memory into non-swappable memory. Once memory is locked, SVDisk will behave like a RAM drive without paging delay. The size of the lock can be specified by the user, since locking the entire disk as non- swappable can have serious performance impact to OS/2's virtual memory operation.
  • A 32-bit command line utility and a 32-bit PM application are included to provide complete control of all the capabilities of SVDisk.