T or F questions

Xin Sun (sun.simon@usa.net) Thu, 13 Apr 2000 20:04:18 -0700 

From: "Xin Sun" <sun.simon@usa.net>
Subject: T or F questions
Date: Thu, 13 Apr 2000 20:04:18 -0700




Are these blow answers correct?
(T) A register must be used to implement a parallel input port.
(T) To ensure reliable commucications a DCE should always be connected to a DCE and a DTE should always be connected to a DTE.
(T) No CPU time is used by an interrupt-driven input interface while the device is not is use.
What minimum number of bytes must be left free on an appliation program's stack on an IBM pc to allow interrupts to execute and return properly?
the answer is 3.
Thanks