User`s guide

Chapter 8 - TAPI Debug CARROLL TOUCH
8-4 Touch System Diagnostics (CTDIAG) User’s Guide
CTDIAG loads the value 0H into the BX, CX, and DX registers,
makes the function call to the TAPI driver via the TAPI software
interrupt (usually 55H) and displays the returns in the registers, as
shown in Figure 8-2.
Figure 8-2. SFP TAPI Debug Results
An AX value of 4 is the correct function call for
GetCommunicationParameters.
BX is split into a high and a low
value: BH represents the driver type and its value of 2 is a code for
an RS-232 controller; BL represents the comm port, with a value of
1 in this example. CH and CL are the parity and baud rate which, in
this case is 0 (no parity) and 3 (baud rate of 2400). Remember that
these are the parameters used by TAPI to communicate with the
controller - not the parameters used by CTDIAG.
The TAPI driver is installed and operating correctly, since it has
returned the proper communication parameters for your RS-232 in
response to the
GetCommunicationParameters
command.
6. Press ESC to exit TAPI Debug Mode and return to the Test Menu.