摘要 |
A computer system includes a chipset which controls the gate-A20 signal and the CPU RESET signal in a conventional manner in response to commands from a system microprocessor. The computer system further includes a peripheral controller which is programmed to generate an alternative gate-A20 signal and an alternative CPU RESET signal when the peripheral controller has been commanded to override the corresponding signals from the chipset. Two signal selectors controlled by the peripheral controller select either the gate-A20 signal and the CPU RESET signal from the chipset or the alternative gate-A20 signal and the alternative CPU RESET signal from the peripheral controller as respective outputs to control operations of the computer system. The use of the alternative signals permits certain operations of the computer systems to be directly controlled by an application program without being intercepted by the operating system.
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