Using Letter
About Letter
History, Future,
and Credits

Letter v2.3 User Guide

  Letter v2.3 Copyright 2000: Emir Sakic

Welcome to Letter v2.3 User Guide.
This guide will help you use Letter v2.3 - a TI-83/83+ ASM ION text processing program.


Some of the special characters available. The LOAD screen.
Use Letter 2.3 to take any notes... Let the Letter remember your equations.


Click to see alternative keymaps to the left.

Using Letter v2.3

Program: Letter v2.3
Description: A TI-83/83+ ASM ION text processing program
Code: ASM SQUISHED ION compatible
Size: 1573/1633 bytes
Author: Emir Sakic
Date: 17.12.2000

This is a TI-83/83+ assembly program that allows you writing text on TI-83/83+ with lower and upper case letters and all ASCII chars available on TI-83/83+.

The Letter v2.3 features:

  • Capital and small letters
  • Numbers
  • All special chars available on TI-83/83+ like @ & # ~ \ % and many more
  • Fast delete, one line and total clear
  • Saving and opening as many files as you want
  • Deleting files
  • Changing contrast showing the contrast indicator
  • Very nice interface both on the main screen and save/open screen
  • Batteries friendly.

How to use:
Make sure that you have ION installed on your TI-83/83+.

  1. Send letter.83p / letter.8xp to your calculator. Start ION and select Letter v2.3.
  2. You will see the Letter logo for couple of seconds.
    You can also skip it pressing [ENTER].
  3. You are coming to the home screen with a cursor in the upper left corner.

    Now you can write lower and upper case letters, numbers and other chars, delete it, save and open files.

    • Choose case pressing the [Y=] key.
    • Press and hold [LEFT] or [RIGHT] keys to choose special character, and type it pressing the [WINDOW] key.
    • Change contrast pressing [UP] or [DOWN] key.
    • Save your files pressing the [ZOOM] key. You will be prompted to SAVE screen.
    • Type the name of file and press [ENTER]. File is saved now.
    • Open your files pressing the [TRACE] key. You will be prompted to LOAD screen.
    • Choose the file you want to load pressing the [RIGHT] key and press [ENTER]. File is loaded now.
    • Delete a file pressing the [Y=] key on the LOAD screen.
    • Exit the LOAD screen without loading pressing the [GRAPH] key.
  4. Quit pressing the [GRAPH] key.

The Letter v2.3 uses the TI-83/83+ home screen with the 16x8 character format.

Write important stuff (formulas, tel. numbers, addresses or anything else), save it and open whenever you need it.

Files you save are protected and can be found only by the Letter v2.3 or by TI-83/83+ OS memory delete option.

Note that the Letter v2.3 is not written to help you cheat. Its purpose is to remind. :)

Saved files are saved like any usual program on TI-83/83+ and take 133-138 / 136-141 bytes each depending on the file name.
They get prefix 'let' in the name. So if you save a file and type TEST on the SAVE screen its name will be letTEST.
If you want to delete some file later you can do it like you would delete any other TI-83/83+ program.
You can delete files directly within the Letter v2.3 from the LOAD screen too.

An archived file on TI-83 Plus can be loaded, but you can't save it over or delete. If you try you will get an "Unarchive file!" message.
Read the notes below about archiving the Letter itself!

Important Notes

ASM program

The Letter v2.3 is a TI-83/83+ program written in Assembly. There is always a risk executing an ASM code.

You should "Back Up" all your important data before you start an ASM program.

I am not responsible at any way if this program causes your calculator to crash and lose memory.
Anyway it's been tested carefully and there shouldn't be any bugs at all.

If you "Back Up" the files it should be remembered that all files must be loaded after the Letter v2.3. If not the RAM will crash if you try to delete a file within the Letter v2.3.

Due to this fact you should never execute Letter if it's archived on TI-83 Plus when you intend to delete a file.
It's safest to always keep the Letter in RAM at least when you have files saved on the calculator.


About Letter v2.3

This program is written by Emir Sakic, it is Free Ware and may be copied freely.

Anyone interested in the Letter v2.3 source code can request it by mail.

If you edit the program, please keep my copyright notice at the exit of the program, along with your own.

The consists of the following files:

letter.83p The main TI-83 program for ION.
letter.8xp The main TI-83 Plus program for ION.
readme.txt The text help file.
UserGuide.htm This file.
Pictures Images used in the UserGuide.

History, Future & Credits

-17.12.2000. v2.3 for TI-83/83+ ION and MirageOS. This version (ION).
Size: 1573/1633 bytes.

-10.12.2000. v2.3 for TI-OS, AShell and SOS.
Searching routine improved and file format changed.
Features contrast changing, deleting files and exiting the LOAD screen.
Better batteries saving.
Size: 1642 bytes.

-17.09.2000. v2.2 for TI-83+ MirageOS.
Same as v2.1 for ION but assembled especially for MirageOS including a program icon. MirageOS hotkey combinations available.
Size: 1315 bytes.

-16.09.2000. v2.1 for ION.
ION compatible both for TI-83 and TI-83+. Uses ION built-in routine to search for program files.
Program size now: TI-83 version: 1279, TI-83+ version: 1286 bytes.

-26.03.2000. v2.0 for SOS.
Version name dumped to 2.0 because it now uses a totally different way for writing and saving files.
Program size is now only 1295 bytes.

-10.01.1999. v1.0. First version.
Size 3526 bytes. Big and unpractical. Could save only one file.

-Future versions:

1. Scrolling screen support.
Files will not be limited at 111 chars and you will be able to scroll text up and down and save file with any size you want.

2. Improved input routine that would allow prompt back without deleting.

3. You tell me. :)

Thanx to:

-Dan Englender and Kouri Rosenberg
for their help on previous versions.

-Nathan Minor
for revising the html help file.

If you have any suggestions or comments please e-mail me on