Thanks for this advice!

I found it!

http://www.weihenstephan.org/~michaste/pagetable/mac/Inside_Macintosh.pdf

I will start with the program Sample. 

I already see a problem. THINK PASCAL complaints about missing these:

USES {$0 Obj/MemTypes } MemTypes, {basic Memory Manager data types} 
{$0 Obj/QuickDraw} QuickDraw, {interface to QuickDraw} 
{$0 Obj/OSIntf } OSIntf, {interface to the Operating System} 
{$0 Obj/Toollntf } Toollntf; {interface to the Toolbox} 
 
Where to add this MemTypes, QuickDraw, OSIntf and Toolintf... Is this also Pascal code? Is this part of some other tool?