Path: utzoo!attcan!uunet!spool.mu.edu!think.com!hsdndev!husc6!zariski!fry
From: fry@math.harvard.edu (David Fry)
Newsgroups: comp.sys.mac.programmer
Subject: Using THINK C from THINK Pascal
Message-ID: <5845@husc6.harvard.edu>
Date: 1 Mar 91 12:06:12 GMT
Sender: news@husc6.harvard.edu
Organization: Harvard Math Department
Lines: 25
Originator: fry@zariski


I'm trying to interface a THINK C library with a friend's THINK 
Pascal program.  My C function is defined:

pascal void MyFunc(Ptr aPtr, short aShort, unsigned char aByte);

The problem is how to define it in Pascal and pass parameters to it 
so that aByte gets the proper values.  I've tried a variety of 
things, and only

PROCEDURE MyFunc(aPtr: Ptr; aShort: INTEGER; aByte: BOOLEAN);

comes close.  Defining aByte as a CHAR or Byte still uses 16-bits, so 
only the high byte is getting passed to the C routine.  BOOLEAN uses 
8-bits, but it is equivalent to a char, rather than an unsigned char, 
so the high bit is unusable.

Should I define a type of PACKED ARRAY [1..1] of CHAR, or some such?

Thanks for any help.

David Fry                               fry@math.harvard.EDU
Department of Mathematics               fry@huma1.bitnet
Harvard University                      ...!harvard!huma1!fry
Cambridge, MA  02138