This is my work
#DEFINE GENERIC_READ 0X80000000
#DEFINE GENERIC_WRITE 0X40000000
#DEFINE OPEN_EXISTING 3
#DEFINE FILE_FLAG_OVERLAPPED 0X40000000

Declare WriteFile in kernel32 hFile As integer, lpBuffer As Any, nNumberOfBytesToWrite As integer, lpNumberOfBytesWritten As integer, lpOverlapped As Any) As integer

Declare ReadFile in kernel32 hFile As integer, lpBuffer As Any, nNumberOfBytesToRead As integer, lpNumberOfBytesRead As integer, lpOverlapped As Any) As integer

declare integer CreateFile in kernel32 lpFileName As String, dwDesiredAccess As integer, dwShareMode As integer, lpSecurityAttributes As SECURITY_ATTRIBUTES, dwCreationDisposition As integer, dwFlagsAndAttributes As integer, hTemplateFile As integer

*this does not work
ICDEV=CreateFile('COM1',GENERIC_READ or GENERIC_WRITE,0,null,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,0)

what is wrong?