HP Vectra Technical Reference Manual page 470

G.9.2 Application Resident EX-BIOS Driver
This example demonstrates the use of an application resident EX-BIOS driver. The driver utilizes
the Touch Screen logical device driver V_LTOUCH, and its associated event driver
V_EVENT_TOUCH.
The driver utilizes V_LTOUCH to move the cursor around the screen. V_LTOUCH returns the
current row and column address of the point the screen is being touched. The example driver in
turn utilizes the STD-BIOS Video driver (INT 1OH) to change to position of the displayed cursor to
match the screen coordinates returned by V_LTOUCH.
This driver also utilizes the button state data returned by V_LTOUCH. When the screen is
touched (a button make) the driver changes the shape of the cursor from an underline to a box
or full character cell. The shape of the cursor is restored to an underline when the finger is
removed (a button break).
Notice in the initialization section of the code that the CS:IP of the driver's service routine
(TOUCH_HANDLER) and the driver's DS are substituted into the V_EVENT_TOUCH vector in
the HP_VECTOLTABLE. The existing contents of that vector are returned by the function. The
driver stores these values in its data area, and restores them when the driver terminates (a
'I\'
character is typed at the keyboard). All HP_VECTOLTABLE vectors that are replaced with
application program resident drivlers should restore the original values in the vector when the
application program terminates.
The listing for this driver can be found in Section 4.
G.9.3 Non-HP-HIL Input Devices
The next program listing is an example of how to integrate non-HP-HIL input devices into the
Input System. This driver interfaces to an RS-232 mouse. It converts data frames received from
the mouse into GID motion and button ISR Event Records. It integrates itself into the Input
System by calling the V_SINPUT driver once these ISR Event Records have been constructed.
The PGID driver is the physical device driver for all devices inputting graphic motion and button
state data. The initialization code must create a PGID driver for the V_SINPUT to pass the ISR
Event Record. It builds a driver header and physical describe record, allocates a free
HP_VECTOLTABLE vector, and installs the PGID driver with V_LHPMOUSE as its parent
driver.
The driver is structured as a DOS installable device driver. The COM port the mouse is connected
to can be specified in the CONFIG.SYS command line.
Driver Writer's Guide 461