The TI-85 was designed as a powerful engineering and calculus calculator. It was the first TI calculator to have a link port and assembly programming capability (through an unintentional loophole). It has since been eclipsed by the TI-86, which features TI-85 compatibility along with more advanced features.

» Official TI-85 home page at Texas Instruments
» TI Connect for the TI-85
» TI-Graph Link for the TI-85
» Guide Books from Texas Instruments
» Bid Specifications
» Graphing Calculator Comparison
» TI Online Store

» TI Connect
The TI Connect is the latest link cable produced by TI. It has a higher data transfer rate than the TI-Graph Link cable. It's a USB cable and lets you transfer data files (such as programs) between your calculator and your computer. TI Connect will only work on MacŪ computers.

» TI-Graph Link
The TI-Graph Link is the older link cable produced by TI. It does not have as high of data transfer rate, but it does work wih almost all calculators. It connects to your serial port and like TI Connect is widely used to transfer data files (such as programs) between your calculator and your computer.

From time to time, TI will update the internal code of their calculators to work around bugs, optimize functions, and even add features. This results in several versions of each calculator in the marketplace. You can check the ROM version of your TI-85 using the following key sequence and reading the number on your screen:

Known ROM versions: 1.0, 2.0, 3.0A, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0

Also see Assembly Programming.

» Boosting the TI-85
These modifications to your TI-85 can overclock the calculator to 3-4 times its original speed.

» Expander 2
The Expander 2 is an add-on device to add 512K of additional memory to your TI-85 for around $45.

» I2C Temperature Sensor
The I2C Temperature Sensor is a device which plugs into your calculator's link port and displays the measured temperature on the calculator.

» IR Link
The IR Link allows you to control infrared devices from your calculator or communicate with other calculators (to play games or chat) over a wireless connection.

» Light Flasher
The TI-85 Controlled Light Flasher lets you direct sequences of flashing lights from your calculator.

» Link Cables
Link cables let you transfer data files (such as programs) between your calculator and your computer.

» Power Extension Page
The Power Extension instructions will show you how to use AA (instead of AAA) batteries without making any modifications to your calculator.

» Power Port
The TI-85 Power Port is a modification to allow your calculator to run from an external power supply.

» SPinTerface Page
» SPinTerface Cartridges
The SPinTerface port is a custom-made modification to the TI-85 allowing the calculator to interface with external battery packs, light flashers, memory expanders, speakers, and other devices.

» TI-85 Turbo Page
These modifications to your TI-85 can overclock the calculator to 3-4 times its original speed.

» Electroluminescent Backlighting a TI-85
If you'd like to be able to use your TI-85 in the dark, these modifications will help you install electroluminescent backlighting in your calculator.

BASIC programming on the TI-85 is nearly identical to the TI-86

History: Assembly language programming was not supported by TI when the TI-85 was released. As with the TI-82 and TI-92, the calculator had to be "hacked" to enable assembly programming.

An analysis of memory backups sent to a computer showed that items in the CUSTOM menu were represented in the backup as pointers to memory locations. Assembly code was stored in a string variable and sent to the calculator in a fixed position - the first variable sent after a memory erasure - and its memory address was found after another backup to the computer. This address was placed in a CUSTOM menu entry field in the backup file, the file was sent back to the calculator, and when the CUSTOM entry was selected, it executed the new assembly code.

» TI-85 Assembler Programming by Greg Parker
» TI-85 ZShell Programming with CAZ by Miklos Bergou
» Usgard Programming: Lesson 1 by Terry Peng
» Usgard Programming: Lesson 2 by Terry Peng
» The Usgard School by Jimmy Mårdell
» The ZShell School by Jimmy Mårdell
» The Guide by Jimi Malcolm

Several emulators are available to let you simulate TI calculators on your computer. To learn how to download a ROM image from your calculator, see our Emulators page.

Emulator Software
Name Platform   Calculator(s)   TI-85 Emulator DOS           85            TI-85 Emulator (another one) MacOS           85            TI-8x Emulator DOS     82  83    85  86          TI86EMU Windows           85  86          TIGraph Windows Home Page          85            Virtual TI Windows     82  83  83+  85  86  89  92  92+