Bank Switching Definition/Meaning:
A technique for memory management commonly used in microcomputer
systems that require more memory than the microprocessor can directly address. A
typical 8-bil microprocessor can directly reference a 16-bit address space (64K
bytes). In systems requiring more than 64K bytes of memory, such as multiuser
systems, bank switching can be used to overcome the addressing limitations of
the microprocessor. In a bank-switched system, different banks of memory are
selected by writing different bit patterns to a specified output port. Each bank
may contain as much memory as the processor can address, and the number of banks
supported can be very large. In practice one bank is often dedicated to each
user of the system with an additional bank reserved for the operating system.
Bank switching is similar in concept to memory segmentation (see segment) but
does not require the use of a processor
that knows about a segmented address space. Note also that an entire bank of
memory may be allocated to a single task, whether it needs all of it or not,
whereas more sophisticated memory-management schemes can make more efficient use
of physical memory.
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