addressed sequential access的用法和样例：
- VSAM? Virtual Sequential Access Method?
- The time it took was irrespective to their address sequence. Magnetic disc is a form of storage which provides the convenience of random access. See Sequential access.
- Generic class allows sequential access either from the head to the tail or from the tail to the head.
- ISAM是indexed sequential access method的缩写。ISAM drivers are used to update file formats other than its own.