Sequential access memory

In computing, sequential access memory (SAM) is a class of data storage devices that read stored data in a sequence. This is in contrast to random access memory (RAM) where data can be accessed in any order. Sequential access devices are usually a form of magnetic storage or optical storage.^[1][2]

While sequential access memory is read in sequence, arbitrary locations can still be accessed by "seeking" to the requested ___location. This operation, however, is often relatively inefficient (see seek time, rotational latency).

Magnetic sequential access memory is typically used for secondary storage in general-purpose computers due to their higher density at lower cost compared to RAM, as well as resistance to wear and non-volatility. Magnetic tape is a type of sequential access memory still in use; historically, drum memory has also been used.

See also

• Sequential access
• Basic sequential access method (BSAM)
• Queued sequential access method (QSAM)
• Secondary storage
  • Hard disk drive
  • Solid-state drive
• Magnetic storage
• Magnetic tape
• Drum memory
• Locality of reference
• Streaming media

References

1. difference between sequential and random access operations
2. Turing machine model of computation sequential access memory