>>>>>I want to write data to lpt1 port to control PCU customer display.
>>>>>The only way to do using vfp native commands is "run copy fn lpt1"
>>>>>but this is too low for disply control.
>>>>>
>>>>>So the only possibility is to use API.
>>>>
>>>>Did you try COPY FILE (filename) TO LPT1:
>>>
>>>I run (w95 osr2, vfp build 415)
>>>
>>>copy file c:\autoexec.bat to lpt1
>>>
>>>a message
>>>
>>>c:\vfp\lpt1 already exists, overwrite it?
>>>
>>> appears
>>>If i choose Yes, an Invalid seek offset error occurs!
>>>
>>>Only
>>>
>>>!copy file c:\autoexec.bat to lpt1
>>>
>>>works, but this is TOO slow for PCU display and requires lpt1 to be captured.
>>
>>It's not a problem to remove 'overwrite' message (SET SAFETY), but Invalid offset signals something more serious. I use this way to print reports from files.
>
>Edward, do you have and idea why copy file ... to lpt1 produces invalid seek offset error? I can't put it work. I use network printer.
>
>"???" command with spooler and other print command will work.

Sorry, I don't know. You probably saw stupid description in Help for this error. It's something related to binary internal processing.