Introduction to Assembly

You want more games for your shiny new TI-84+CE? Why don’t you make them yourself?

What is assembly?

Assembly is a very powerful language that you can use on your TI-84+CE! When you write in assembly, you write in a human readable form of machine code, which allows you to create quicker programs that can access and do more than TI-BASIC. Mistakes in assembly can be messier than in TI-BASIC- but usually only as severe as a ram clear, so before you start this guide, back up your calculator to prevent any data loss!

Setting up

What you’ll need

A program editor

To write your program, you can use almost any text editor. We prefer Notepad++, as it is really easy to use for beginners and it has some nice features for developing.

Download Here: Notepad++

An assembler

An assembler lets you take the code you have created and make it into a program that the TI-84 Plus CE can use. We recommend SPASM-ng when coding in eZ80.

Download Here: Spasm-ng

A debugger/emulator or a TI-84+CE

A debugger is useful for seeing what your code does and finding errors. Unfortunately, at the time of this writing, the only 84+CE emulator available for download is CEmu, which is hardly in a usable state. Because of this, we need TI’s Connect software to transfer our programs to our calculator, and we’ll also need a link cable (which should have come with your calculator) and the calculator itself.

Download Here: TI Connect CE

TI 84+CE Equates File

This file tells your program and the compiler where things are located on your calculator.

Download Here:

Setting up the assembler

Alright, now we can get to putting together all the materials we just downloaded! Create a folder and call it “My First ASM Program” (or anything else). Inside create three folders: bin, includes, and tools. Rename SPASM to just spasm.exe and put it inside the folder named tools. Put inside the includes folder.

Create a file named Example.asm in your folder. Inside this file, write the following code.

#include "includes\"

 .assume ADL=1
 .org userMem-2
 .db tExtTok,tAsm84CeCmp

 call _homeup
 call _ClrScrnFull
 ld hl,TutorialText
 call _PutS
 call _GetKey
 call _ClrScrnFull
 res donePrgm,(iy+doneFlags)

  .db "Excellent job! :) You havecreated your first assembly program!",0

Don’t worry; we’ll revisit what all this code does later on.

Now, create a file named build.bat. Inside this file, write the following code:

@echo off
tools\spasm -E -T Example.asm bin\Example.8xp
Goto A

Run build.bat by double-clicking on it. Inside the “bin” folder you should see a file named FIRSTPRGM.8xp. Transfer this onto your calculator using TI Connect CE and run it by pressing 2ndCatalog and selecting the Asm( token, then pressing Prgm and selecting EXAMPLE (or whatever you program was called). It should look something like this: Asm(prgmEXAMPLE

If this doesn’t work, try again to make sure you followed each step of the tutorial again. You can also post for help on the Cemetech forums.

In the next lesson we’ll dive right into learning assembly.