michaelh@neon.Stanford.EDU (Mike Hennahane) (04/09/91)
I'm trying to send commands to a driver installed in memory at
startup. My code works fine in the THINK pascal environment, but when
I compile it into a CODE resource (so that I can call it as an
external command from 4th Dimension) it bombs miserably (application
unexpectedly quit (1)). The only thing that I can think of is that
opening and closing the driver is changing something global that 4D
needs.
My question: does my code change anything global that would bomb a
host application if called as a CODE resource? (I'm not supposed to do
anything that relies on the A5 register or change anything like the
grafport, unless I put it back when I'm done...)
Thank you if you can offer ANY help or leads. Please respond via
email, since I'm struggling too much with this to have time to read
this group... :-)
mike hennahane
michaelh@neon.stanford.edu
------code follows----------
unit sendToMIC;
{R-}
interface
function main (var theCommand: str255): str255;
implementation
function main (var theCommand: str255): str255;
var
result: OSErr;
MICRefNumber: integer;
command, return, temp: str255;
count: longint;
begin
result := OpenDriver('.MIC2', MICRefNumber);(* open driver *)
command := concat(theCommand, chr(13)); (* append a CR *)
count := length(command);
result := FSWrite(MICRefNumber, count, @command[1]);(* write *)
return := '';
repeat
count := 64;(* try to read as much as buffer holds *)
result := FSRead(MICRefNumber, count, @temp[1]);(* read *)
temp[0] := chr(count); (* set pascal length byte *)
return := concat(return, temp); (* concat to what we have *)
until (result = eofErr); (* eofErr signals end of return *)
result := CloseDriver(MICRefNumber); (* close driver when done *)
main := return; (* assign return to var param *)
end;
end.