ASPI
Advanced SCSI programming Interface. A standard SCSI soft- ware interface that acts as a liaison between host adapters and SCSI device drivers. ASPI enables host adapters and device drivers to share a single SCSI hardware interface.
ASW
An acronym for Adaptec Software.
ASYNCHRONOUS DATA TRANSFER
A method of SCSI data transfer. This is the type of transfer rate originally introduced with SCSI 1. With this type of transfer method, transfer rates of 2 MBytes/sec are common. See also
SYNCHRONOUS TRANSFER.
Is SYNCHRONOUS faster than ASYNCHRONOUS?
Asynchronous is faster on short cables, while synchronous is faster on long cables. The reason has to do with the propagation delay of the cable; the turn around time of the silicon; and the interlocked nature of the asynchronous handshake.
1)We have measured propagation delays from various cables and found an average of 1.7 nanoseconds per foot, which is roughly 5.25 ns per meter.
2)The
3)The asynchronous transfer uses an interlocked handshake where a device cannot do the next thing until it receives positive acknowledgment that the other device received the last thing.
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