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    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.


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    CPU 6 MHz ZiLOG Z80
    Memory 32K RAM (28K available to user)
    Screen Size 128x64 pixels, 21x8 characters
    Link Port? Yes
    CBL/CBR Support? Yes
    ViewScreen Model Available? Yes
    TI-Presenter Compatible? Yes
    TI Keyboard Compatible? No
    TI-Navigator Compatible? No


    » TI Connect for the TI-85
    » TI-Graph Link for the TI-85
    » Guide Books from Texas Instruments


    » 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 MacĀ® 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:

    [2nd] [MODE] [ALPHA] [S]

    WARNING: After entering the above key sequence, DO NOT PRESS ENTER! If you do, your calculator's memory will be erased. Press any other key to exit back harmlessly.

    Known ROM versions:

    • 1.0
    • 2.0
    • 3.0A
    • 4.0
    • 5.0
    • 6.0
    • 7.0
    • 8.0
    • 8.5V (ViewScreen model)
    • 9.0
    • 10.0


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

    » 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.

    » 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.

    » 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.

    » Tutorials at TI-Freakware


    History: Assembly language programming was not supported by TI when the TI-85 was released. As with the TI-81, 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 Guide by Jimi Malcolm
    » Tutorials at TI-Freakware


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

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