HP Vectra Technical Reference Manual page 208

SECTION 6. MOUSE
The mouse driver discussed in this section provides the HP Mouse with the Microsoft Mouse (tm)
compatible (INT 33H) application interface. There are two additional mouse drivers supplied with
the system, the pointer driver (simple mouse) discussed in Section 4 and the cursor key emulator
discussed in Appendix G. Some of the terminology in this section is defined in Section 4.
6.1 Overview
The industry standard mouse is accessed through software interrupt 33H. The INT 33H driver
receives data from the logical mouse driver (V_LHPMOUSE). If the HP-HIL mouse is present at
boot time, V_LHPMOUSE initializes INT 33H to the industry standard interface driver. The
industry standard interface supports both a polled mode and interrupt mode of data retrieval.
, . The following data flow outlines the process of mouse data input.
1. The mouse is moved. This causes the physical device to generate input data and interrupt
the hardware interface level drivers.
2. The hardware interface level processes the interrupt and passes the data (ISR Event Record)
to the logical mouse driver (V_LHPMOUSE).
3. V_LHPMOUSE scales and clips the input data and stores it for the industry standard
interface to use.
4. If using polled mode the application must inquire if the data is available. If using interrupt
mode the application will be interrupted to notify it that the data is available (via INT 33H).
Steps 1 and 2 above have been discussed in Section 4. Step 3 involves processing the ISR Event
Record into the data format used by the INT 33H driver. At this point, if the user has defined and
installed an interrupt handler with function F33_SET_USR (OCH), that routine will be called. INT
33H also defines functions to allow the application to poll for mouse data.
The screen modes supported by the mouse driver are shown in table 6.1 The (0,0) origin for the
display is in the upper left hand corner of the display. All data reported is in the ranges: 0 to 199
for y-axis and 0 to 639 for the x-axis.
Mouse 199