Program Structure

Every program in assembly follows a specific format.

#include "includes\ti84pce.inc"
.assume ADL=1
.org userMem-2
 .db tExtTok,tAsm84CeCmp

 ; Program code

 ret

But what does all of this code do?

#include "includes\ti84pce.inc"

This is a file that includes lots of locations of routines and variables and various other things in the calculator’s operating system that we can use.

.assume ADL=1

This tells the assembler to assume that ADL mode is on. ADL mode means the processor is using 24-bit register pairs and memory addresses, which is the the calculator’s default.

.org userMem-2

This tells the assembler that this program will be located at userMem-2, so any memory addresses we reference should be relative to that. (The program is actually placed at userMem, but there are two bytes right after this which are removed from the program by the OS before it is placed at userMem.)

.db tExtTok,tAsm84CeCmp

This is exactly equivalent to the Asm84CEPrgm token in BASIC; it tells your calculator that it should be executing an assembly program instead of a BASIC program. This is why when you try to run an assembly program on your calculator without the Asm( token, you get an error (and why you can’t run a BASIC program with the Asm( token).

; Program code

This is where you can actually write the program’s code.

ret

This exits the program (usually). More on that later.

In the next tutorial we’ll be learn about how numbers work on your calculator.