TI-84 Plus series

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TI-84 Plus Silver Edition

The TI-84 Plus is a graphing calculator made by Texas Instruments that came out spring 2004. There is no original TI-84, only the TI-84 Plus and TI-84 Plus Silver Edition models. It is an enhanced version of the TI-83 Plus. The key-by-key correspondence is the same, but has been improved hardware-wise. The memory is about 3 times as large, and CPU about 2.5 times faster (over the TI-83 and TI-83 Plus). A USB port and built-in clock functionality were also added. The clock can be used to tell the time since the RAM last cleared (if set correctly, it will tell the actual time). It is merely a slightly enhanced version of the TI-83 Plus Silver Edition, as it retains many of the same system specs. It is interesting to note that the USB port on the TI-84 Plus series is USB On-The-Go compliant.^[1]

The TI-84 Plus Silver Edition came out in 2004 as an upgrade to the TI-83 Plus Silver Edition. Like the TI-83 Plus Silver Edition, it features a 15 MHz Zilog Z80 processor, 24 kB user available RAM (the actual chip is 128 kB, but TI has yet to code support for the whole thing into an OS), and 1.5 MB 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. If you take out the batteries while the TI-84 is running, it clears the RAM. A kickstand-style slide case and interchangeable colored faceplates are also available.

There are three different types of programs which can be downloaded or programmed into it: TI-BASIC, Z80 assembly language, and Flash (applications). There are a wide range of applications that this produces, from science classes, to games, to calculus to notetaking (when put together with a separately sold keyboard). The TI-84 Plus Series is exactly like its predecessor in that it can be used on the SAT and ACT examinations as well as International Baccalaureate examinations. However in some cases those administering the exam may reset the calculator's memory before-hand to prevent cheating through the use of built in programs or other data.

When OS 2.30 was initially released, users noticed the speed of graphing was greatly reduced. This was explained by that the update added asymptote checking in graphing.

In January of 2006, Texas Instruments released v 2.40 operating system for the TI-84 plus series. The most noticeable addition to the new OS was the teacher key, allowing the teacher to disable any programs installed on the calculator, so they are unable to be used on tests, etc. OS version 2.41 for the TI-84 plus series was released in May 2006.

1 Assembly Language
2 Technical specifications
3 See also
4 External links

[edit] Assembly Language

Z80 assembly language gives a programmer much more power over the calculator than the built-in language, TI-BASIC. On the downside, Z80 assembly is much more difficult to learn than TI-BASIC and very cumbersome for coding large programs. Z80 assembly language can be programmed on the computer and sent to the calculator via a USB port, or written by hand directly into the program editor using the opcodes or compiled using third party compiler programs. Programs written in assembly are much faster and more efficient than those using TI-BASIC, as it is the processor's native language, and does not have to be interpreted like Ti-Basic. Most "fast" games, programs that give more power over the calculator, and Applications written for the TI-84 series are written in Z80 assembly. An example program that displays "Hello World" on the screen:

  ld a,0           ; loads 0 into register a
  ld (curRow),a    ; loads 0 in the Row (Top of screen)
  ld (curCol),a    ; loads 0 in the Column (Left of screen)
  ld hl,Hello      ; Loads the address that points to "Hello World" into register hl (16-bit)
  B_CALL PutS      ; Puts "Hello World" on the screen in the top left corner
  ret              ; pops off the last data pushed onto the stack. 
                   ; May be used to end the program depending on what's
                   ; on the stack
 Hello:            ; Label, that has an equate address in memory. The hex values of
        ;"Hello World" is stored at the start of label, Hello
  .db "Hello World!",0  ;defines a series of bytes in memory which start at the label Hello

compared to its equivalent TI-BASIC Program. However, despite TI-BASIC's lesser control over the calculator, its simplicity encourages simple math, science, etc. programs to be coded in it.

  Output(1,1,"Hello World!")

  Disp "Hello World!"

[edit] Technical specifications

CPU: Zilog Z80 CPU, ;Flash ROM; 2 MB
RAM: 32 KB RAM (128 KiB on Silver Edition, however the extra 96 KiB is not user accessible by default); 84 series expandable via special software to use up disk space on a USB memory drive.
Display: Text: 16×8 characters (normal font); Graphics: 96×64 pixels, monochrome
I/O: Link port, 9.6 kbit/s; 50 button built-in interface
USB
Link port
Power: 4 AAA batteries plus 1 CR 1616 or CR 1620 for backup
Integrated programming languages: TI-BASIC and machine code. Assembler and C require a computer with a Z80 cross-compiler or an on-calc assembler.