>I need to pass a parameter to a dll function using an unsigned byte and am having some problems.
>
>DECLARE INTEGER LoadToRam IN Hc11DownLoaderDll INTEGER,STRING,STRING
>
>retval = LoadToRam(portnum,CHR(255),NULL)
>
>I need to pass the CHR(255) and the portnum as unsigned char but Foxpro sends it as a signed char.
>

Try:

DECLARE INTEGER LoadToRam IN Hc11DownLoaderDll INTEGER, INTEGER, INTEGER
portnum = 1
commandcode = 255
Ptr = 0
RetCode = LoadToRam(portnum, commandcode, ptr)

This takes advantage of the fact that integer values are passed LSB first, so a byte uses only the first byte of the 4 byte integer.



>A VB implementation uses the following.
>
>Private Declare Function LoadToRam Lib "Hc11DownLoaderDll.dll" _
> (ByVal comPort_ As Byte, ByVal commandCode_ As Byte, _
> ByRef progressBarPtr_ As Any) As Integer
>
>command = CByte(&HFF)
>
>comport = CByte(cboComPort.Text)
>
>result = LoadToRam(comport, command, vbNullString)
>
>A C++ implementation of course just does a cast to unsigned char for the character byte 0xFF.
>
>I need a way to do it in VFP 6.0 if it is possible.
>Any help is appreciated