1. Introduction
16
Keyboard Controller
The ZT 8904 includes a PC/AT
®
keyboard controller that operates when the zVID local
bus video adapter is installed. The keyboard connector is located on the zVID adapter.
AC Power-Fail Protection
With the addition of an AC transformer (connected to connector J3), the ZT 8904
monitors AC power to permit an orderly shutdown during a power failure. When AC
power falls below an acceptable operating range, a non-maskable interrupt is generated
to notify the CPU of an impending power failure. When the application software receives
this notification, it saves critical data before the CPU is reset.
See Chapter 16, "
AC Power Fail
," for more information.