HP Vectra Technical Reference Manual page 64

SECTION 4. INPUT SYSTEM AND HP-HIL
The Input System is a set of drivers which support the HP-HIL input devices. Up to seven HP-HIL
input devices may be connected at one time. The Input System can support properly integrated
non-HP-HIL devices as well. In its basic configuration, the system has one input device, the
keyboard.
4.1
Overview
The standard devices that connect to the system via the HP-HIL link are the keyboard, mouse,
touch screen and tablet. The application interface for the keyboard is described in Section 5. The
industry standard interface for the mouse (INT 33H functions) is provided in Section 6. The
interfaces for simple mouse, touch screen and tablet support are described in this section.
The architecture of the Input System is divided into two levels (see figure 4.1). The application
interface level allows the programmer to communicate with the HP-HIL devices with minimum
overhead. The second level, the hardware interface level, allows programmers to manipulate the
internals of the system. With this interface, support for additional devices can be added or the
data path of existing ones re-directed.
The first portion of this section provides an overview of the application interface level, a detailed
description of the actual interfaces and how to access them. The second portion of this section
describes the hardware interface level.
4.2 Application Interface Level
Application programs interface with the Input System through a set of logical device drivers. The
Input System has an application interface for keyboard, tablet, pointer (simple mouse), and touch
screen input devices. These drivers are shown in figure 4.1.
Input System and HP-HIL 55