Port : A port is an adapter which enables a system to communicate with its input/output devices. Using port user can connect I/O devices and use them. There various types of port such as parallel port, serial port etc.
Differences Between Fixed Port and Variable Port Addressing
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Fixed Port Addressing
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No.
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Variable Port Addressing
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Fixed port addressing is of 8-bit.
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01
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Variable port addressing is of 16-bit.
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In this case, only the lower AX, that is, AL is used.
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02
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In this case, AX is used.
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In personal computer we can not use fixed port addressing as all 16-bits must be used.
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03
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We use variable port addressing in personal computer.
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