ICS PCI-WDT 500, Руководство по эксплуатации продукта

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Manual Number: 00650-144-1 Page 21
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 than 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.