Overview

The TI-92 Plus and TI-89 contain built-in assembly language support. TI has already released limited information about assembly programming. In addition, there are two environments availible for developing and executing assembly language programs. PlusShell was the first to be released. It uses essentially the same source format as Fargo, so most programs ported from the TI-92 use this shell. DoorsOS features a graphical GUI, libraries with advanced file handling and graphics functions, and built-in crash protection. Since development and support of PlusShell has been temporarily discontinued, DoorsOS seems to be the environment of choice for TI-89 and TI-92 Plus users. Instructions for installing these shells are included with them.

Troubleshooting

One of the most common and frustrating problems with assembly language programs for the TI-89/92 Plus is the lack of version checking for libraries. As a result, many users cannot get programs to run, or even worse, correctly written programs may seem to cause the calculator to crash. The best way to prevent these problems is to download the official DoorsOS and/or PlusShell zip files, and only use the libraries included with them. Otherwise, you may unknowingly be using outdated libraries.

When running assembly language (ASM) programs, your calculator is no longer protected by TI's OS from fatal errors and memory corruption. Therefore ASM programs may cause your calculator to unexpectantly freeze up. If this happens, you must reset the calculator's memory. This will erase all data on your calc, and you will need to reinstall any software that was previously installed. One of the following methods should work:

TI-92 Plus

• Press [Hand] + [2nd] + [On] at the same time.
• Remove one of the AA batteries. Hold [(-)] and [)] as you reinstall the battery. Continue to hold [(-)] and [)] for 5 seconds.

TI-89

• Press [2nd] + [Left] + [Right] + [On] at the same time.
• Remove one of the four AAA batteries. Hold [(-)] and [)] as you reinstall the battery. Continue to hold [(-)] and [)] for 5 seconds.

Links

• TI-92 Plus at Texas Instuments
• TI-89 at Texas Instuments
• PlusShell Homepage (No longer available)
• DoorsOS Homepage