>>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.