Why use the STACK?

1) Registers are in short supply

2) Programs using stack are easier to document and 
easier to use. Think  of int 21h

3) HLLs use the stack. Most large projects use a
combination of HLLs and Assembly. To get your
assembly code to work with the rest of the of the HLL
code you mustuse stack to pass parameters.



Libraries
-----------
We write fairly general reusable procedures useful in
a wide variety of situtations. 

How do we organize and manage these procedures?
Another software engineering problem.

We could just  physically include the code for 
for a procedure with any program that uses it.
Merge a couple of files and voila, we're done.

In MASM

INCLUDE fileName

requests MASM to INSERT a copy of the disk file named
"fileName" at the current position in the source
code.

But there is a far better way than include for
storing, managing, and accessing procedures. ==> LIBRARIES



MASM assmebles a program into a .OBJ (object) file
LINK links together one or more .OBJ files to produce
a .EXE file.

LINK is designed to handle specially formatted
collections of .OBJ  files called LIBRARIES

LINK will search thru one or more libraries for a
required procedure and will adjoin the code for these
procedures to the program. 

For example, a library may contain 100 procedures of
which your program requires only 3. LINK will find
these 3 and extract the code only for these 3 and
links this code to your program.

To set up a library type

	lib libName

Read Pgs 122 - 123 in the book. Look at MASM manual


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Review:

1) Representation
	a) 2's complement
	b) Overflow
	c) sign extension
	
	d) ASCII

3) Programming in Assembly

	MASKS
	Procedures
	Using the stack

Nothing on Libraries until the next exam.

Good Luck.