Access IOD-144 - page 12

DIGITAL INPUT/OUTPUT CARD IOD-144 USER MANUAL
5-2
WINDOWS UTILITY DRIVERS
ACCES provides drivers for use with 16- and 32-bit Windows languages. ACCES32, a 32-
bit driver, provides hardware register access when writing software for Windows 95/98/NT.
The same hardware level access is provided for 16-bit applications using VBACCES, a 16-
bit driver for VisualBASIC 3.0. Both drivers are in the form of a .DLL and sample code is
included that demonstrates their use. Together, these files allow you to access the port
and main memory space in a fashion similar to BASIC, QuickBASIC, Pascal, C/C++,
Assembly, and most other standard languages using the four functions listed below.
To use VBACCES, you must create a .MAK file (File l New Project) similar to the sample
provided (or else, modify your existing project file) and include the .GBL file (File |
Add File). To use ACCES32, refer to the sample code for the language -specific
commands for adding the DLL to the project.
InPortb
Function: Reads a byte from a hardware port. Due to limitations of VisualBASIC,
the number is returned in an integer.
Declaration: function InPortb(byval address as integer) as integer
InPort
Function: Reads an integer from a hardware port. This function returns the 16-bit
value obtained from reading the low byte from address and the high byte
from address+1.
Declaration: function InPort(byval address as integer) as integer
OutPortb
Function: Writes the lower eight bits of value to the hardware port at address. This
function returns the value output.
Declaration: function OutPortb(byval address as integer, byval
value as integer) as integer
OutPort
Function: Writes all 16 bits of value to the hardware port at address. This function
returns the value output.
Declaration: function OutPort(byval address as integer, byval value
as integer) as integer