This is the definition that I found and the driver is listed as freeware like the install program is freeware. Patin-Couffin access layer is required device I/O interface for various application so you do not need to force the other drivers to run. Patin Couffin is an alternative to Adaptecâ€™s ASPI. The term ASPI is an acronym that stands for: Advanced SCSI Programming Interface. Operating systems and programs use ASPI drivers to communicate with ATAPI and SCSI devices. The files contained in an ASPI layer are also used in systems that don't contain a SCSI adapter, or SCSI devices... for things such as ripping CD audio and burning CDs.
However, many people prefer Patin-Couffin access layer because:
- ASPI is a registered trademark of ADAPTEC, which mean that we must pay to use or include ASPI in our software, and can't guarantee we will have the right to use it indefinitely.
- ASPI is UNRELIABLE, because there is more ASPI distribution than we can count. Some are very serious and stable, other introduces bugs and problems we can't cope with.
- ASPI does not provide a mechanism to obtain exclusive access on a given drive. this is needed to have a reliable read/write operation.
- Patin-Couffin Layer act faster on drive.
- Most ASPI layers are not plug and play, does not support hot plug and doesn't see units on USB, or firewire buses.
- and so on...
Not sure if VSO is freeware or not but it needs patin couffin to operate.