PCI-DIO48(S)(S) Manual
Page 5-4
Manual 00650-529-1
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
Peek
Function:
Reads a byte from main memory (DRAM).
Declaration:
function Peek(byval segment as integer, byval offset
as integer) as integer
Poke
Function:
Writes the lower eight bits of value to segment:offset.
Declaration:
function Poke(byval segment as integer, byval offset
as integer, byval value as integer) as integer
Note that in all of the above functions, an inherent limitation of BASIC in general and
VisualBASIC in particular makes the values sent less intuitive. All integers in BASIC are signed
numbers, wherein data are stored in two's complement form. All bit patterns must be converted
to-and-from this two's complement form if meaningful display is required. Otherwise, values
returned from the InPortb function will be -128 to 127, rather than 0 to 255. An alternative is to
perform all assignments in hexadecimal, rather then decimal form.
Before the program will execute, the .GBL file must be modified to include the path to the
VBACCES.DLL as appropriate for your system. Merely replace the statement "VBACCES.DLL"
with "drive:path\VBACCES.DLL".
As an alternative to changing the source code, you can copy the VBACCES.DLL file into your
Windows directory. This will allow multiple programs to find the same .DLL without having to
know where it is located. Just leave off all references to a path in the .GBL file as shown in the
sample.
