TI-84 Plus series

The TI-84 Plus Silver Edition was released in 2004 as an upgrade to the TI-83 Plus. Like the TI-83 Plus Silver Edition, it features a 15 MHz Zilog Z80 processor and 24 KB of user-available RAM. The chip has 128 KB, but Texas Instruments has not made an OS that uses all of it. Newer calculators have a RAM chip that has only 48 KB. All calculators with the letter H or later as the last letter in the serial code have fewer RAM pages, causing some programs to not run correctly.[2] There is 1.5 MB of user-accessible Flash ROM. Like the standard TI-84 Plus, the Silver Edition includes a built-in USB port, a built-in clock, and assembly support. It uses 4 AAA batteries and a backup button cell battery. The TI-84 Plus Silver Edition comes preloaded with a variety of applications. These programs are also available for the TI-84 Plus, but some must be downloaded separately from TI's website. It is manufactured by Kinpo Electronics.

TI offers a special yellow version of the TI-84 Plus, inscribed with the words "School Property", for schools to loan out to students. This special design was produced in an effort to combat theft.[3] Owners can buy other interchangeable colored face-plates and slide-cases online. A kickstand-style slide case and other accessories are also available.

In 2011, TI launched the TI-84 Pocket.fr, a miniaturized version of the TI-84 Plus for the French market.[4] In 2012, TI launched the TI-84 Plus Pocket SE, a miniaturized version of the TI-84 Plus Silver Edition for the Asian market.[5]

In 2015, Texas Instruments released the TI-84 Plus T in the Netherlands. This model is very similar to the original TI-84 Plus, but features an LED to indicate whether or not the calculator is in Exam Mode. The hardware of the TI-84 Plus T is similar to the TI-84 Plus Silver Edition, with ninety-six 16 KB pages of archive memory, for a total of 1540 KB. However, unlike the TI-84 Plus, the TI-84 Plus T does not allow users to execute assembly programs. The TI-84 Plus T has 2 different Exam Modes available with different levels of restrictiveness. The most restrictive level does not allow for any existing programs to be accessed, and does not allow any new programs to be created. This mode makes the LED blink green. The second, more moderate Exam Mode is the same, apart from three additional applications being allowed (PlySmlt2, Inequalz and Conics). This mode makes the LED blink orange.

The TI-84 Plus C Silver Edition was released in 2013 as the first Z80-based Texas Instruments graphing calculator with a color screen. It had a 320×240-pixel full-color screen, a modified version of the TI-84 Plus's 2.55MP operating system, a removable 1200 mAh rechargeable lithium-ion battery, and keystroke compatibility with existing math and programming tools.[6] It had the standard 2.5 mm I/O (DBUS) port and a mini-USB port for connectivity and charging. The calculator was praised for its high-resolution (relative to contemporary graphing calculators) color screen, which allowed new pedagogical approaches such as graphing multiple functions together in different colors. It was widely criticized for its slow performance by educators and hobbyists/hackers alike; the performance was attributed to the calculator retaining its monochrome predecessors' CPU to drive a screen displaying 300 times as much image information. Nonetheless it demonstrated the value of a color-screen TI-84 Plus-family calculator and was superseded two years later by the TI-84 Plus CE which was embraced by the calculator hobbyist community. Notable third-party milestones included overclocking the device from 15 MHz to 22 MHz[7] and the third-party Doors CS shell.[8]

The TI-84 Plus CE (known as the TI-83 Premium CE in France) was publicly previewed by TI Education in January 2015[9] and released in 2015. The calculator retains the 320×240-pixel color screen, rechargeable battery, and key layout of the TI-84 Plus C Silver Edition, while removing the 2.5 mm I/O ("DBUS") linkport and moving the USB port and charging LED to the right side of the handheld. The calculator's OS 5.x is incompatible with the TI-84 Plus C Silver Edition's hardware. In addition, the RSA signing key length has been increased to 2048 bits, making infeasible previous efforts to unlock the calculator to unrestricted third-party software development. The calculator has 154 KB of user-accessible RAM and 3.0 MB of Archive memory. It uses the eZ80 processor from Zilog, making all Z80 assembly programs from the previous TI-84 Plus series calculators incompatible. The CE was introduced in multiple colors (Classic (black), Silver Linings, Radical Red, True Blue, Denim (navy blue), Lightning (light blue), Plum Pi (purple); Positively Pink (as of March 2015), Golden Ratio, and Bright White (as of June 2016) were added later), and further colors have since been released. Like the rest of the TI-84 Plus series, certain countries permit its use in examinations.[10] The calculator comes programmed with seven different languages (English, French, German, Dutch, Portuguese, Spanish, and Swedish).

In 2016, the TI-84 Plus CE-T was released for the European educational market. The only significant difference from the CE model is the addition of an LED that blinks while the calculator is in Press-to-Test mode.

CE calculators revision L and later (some L revisions were manufactured on and after April 2019. One way to tell is the face of the calculator is matte instead of glossy plastic) contain an improved architecture, with caching with a more recent flash chip (Winbond 25Q32JVSIQ) than on previous revisions, which contained a Winbond W29GL032C. Due to this change, more recent revisions have seen a significant improvement in overall speed. In 2020, TI Education announced its decision to remove support for assembly and C programming on these calculators in response to a video posted on YouTube detailing how to bypass the test mode on OS version 5.2.2. TI's response was widely considered unnecessary, and led to anger from users. The changes are reflected in OS version 5.5.1 for the European models and OS version 5.6 for the US models. Currently, an exploit called ArTIfiCE has been released that allows for native code execution through a bug in the CabriJR app.

The TI-84 Plus CE-T Python Edition was released in 2021 and provides OS version 5.6 and above with the ability to program the calculator in Python and includes a preloaded bundle of applications.[11] The Python implementation is extremely slow compared to NumWorks and HP calculators due to the use of an ARM coprocessor running CircuitPython, which communicates to the calculator via 115200 baud UART serial.[12] In the North American market, the TI-84 Plus CE Python replaced the existing TI-84 Plus CE in 2021.[13]