Compare TI-92 to TI-92 Plus

This screen shows how much memory is left in the original TI-92 after I loaded my files into it. Looks like a lot, but quite often, especially during more complicated and long symbolic calculations, I was getting an error message saying there was not enough memory to continue the calculations.

This is the original TI-92

The screen below shows how much memory is left after I loaded exactly the same files into TI-92 Plus. Just look at the last two numbers.

This is TI-92 Plus. Click here for more information.

If you think that was impressive, look at these two screens below. The first shows what happens if you electronically upgrade the operating system (for free!). It took me 21 minutes to install the new operating system (version 2.03).

TI-92 after upgrading the operating system to version 2.02

And then I loaded all my programs, data files, and other things back into the calculator. This is the same screen after that operation:

 

Free programs for calculators
 TI-85, TI-86, TI-89, TI-92 and TI-92 Plus

  1. The Moon. You enter any date (also B.C.), the program calculates the "age" of the Moon (counting from New Moon), its distance from the Earth (expressed in terms of the radius of the Earth), approximate ecliptic coordinates for that day, location of the center of mass of the Earth-Moon system (again in terms of the radius of the Earth), makes a drawing of the phase of the Moon (see below), then displays the information again. I have written this program also for TI-85 and TI-86. The screens look pretty much similar to these below. Version for TI-89/TI-92 Plus is made of three parts and takes 3089 bytes of memory. Version for TI-92 is also made of three parts and is about 120 bytes smaller; version for TI-86 takes 1366 bytes of memory.

If you want to have this program, come to my office (Physics Bldg., Office 444) any day (the best time for that is between 3:00 and 5:00 pm). Don't forget to bring your calculator.
You can also get this program from me via E-mail. I cannot also exclude a possibility that this (and other programs described below) will be available in a few days from the Texas Instruments Web Site. If that happens, I will put the address here. To install these programs in your calculator from the TI Web Site you will need the TI Graph Link cable. If you don't have the cable and/or the Internet connection, come to my office.

    Screens of TI-89

    Screen of TI-89: Phase of the Moon on February 12, 1999 Screen of TI-89: Moon data for February 12, 1999

    Screens of TI-86

    Screen of TI-86 Screen of TI-86

    Screens of TI-92/TI-92 Plus

    Screen of TI-92/TI-92 Plus

    Screen of TI-92/TI-92 Plus

  1. Sidereal Time. You enter the date, location of the observer (or select from a short list), and the time, the program calculates the Julian Date and the Local Sidereal Time. After that you can press F1 and repeat the calculations for a different time, new location and time, new date and time, or stop the program. Useful if you are planning observations.
    I have written this program for all the TI calculators listed above and you can also get this program from me for free. See above how to get it. Version of this program for TI-89/TI-92/TI-92 Plus is made of six parts - together they take 4389 bytes of memory, plus a few hundred bytes for temporary variables that the program clears by itself when you stop it running. Version for TI-86 consists of three parts - in all 2558 bytes of memory.

    Screen of TI-89; Version for TI-89/TI-92/TI-92 Plus

  2. Sunrise/Sunset Time. You enter the date, location of the observer (or select from a short list), select the twilight (civil, nautical or astronomical), the program calculates the Local Civil Time of sunrise and sunset, beginning and end and duration of twilight, approximate azimuth of the Sun at sunrise and sunset, approximate ecliptic and equatorial coordinates, duration of the day with and without twilight, time of transit of the Sun across the local meridian, and its altitude above the horizon at that time.
    The TI-89/92/92 Plus version is using eight subroutines - some of them shared with the program calculating the Sidereal Time and The Moon(see above). All this takes 7756 bytes of memory.
    Here are screens of TI-89 (I have made some improvements lately, screen shots will be updated in a day or two):

  3. MintoHz - Converts wavelenghts in meters into frequency in kHz, MHz, or GHz. This program is quite primitive but useful if you have to make these conversions often. Version for TI-89/92/92 Plus is 331 bytes long.

  4. Cnvlbdfr - Converts wavelength into frequency and vice versa. Wavelength may be expressed in Angstroms, nm, mm, cm, or meters (selected from menu). Frequency is displayed in Hz, kHz, MHz, or GHz, depending on the order of magnitude. Wavelength is displayed in meters. Version for TI-89/92/92 Plus is 1553 bytes long (with one subroutine shared with all other programs).
  5. Angres1 - Calculates theoretical (diffraction limited) angular resolution of a telescope. You can enter the observing wavelength expressed in Angstroms, nm, mm, cm, or meters (selected from menu), or you can use the frequency instead (expressed in Hz, kHz, MHz, or GHz, selected from a menu). The result is displayed in degrees, minutes and seconds of arc. Version for TI-89/92/92 Plus is 1650 bytes long (with one subroutine shared with all other programs).
  6. RLCpsr - calculates radius of the light-cylinder for a rotating body (e.g. a pulsar). Very simple, takes only 145 bytes.

    7. Other (non-astronomical) programs

  7. Simuleq1 - Solving systems of linear equations using TI-89/92/92 Plus is quite annoying and complicated, compared to TI-85 and TI-86. This program makes it much simpler, quite similar to TI-85/86. Allows to review and change equations before and after solving, also in case of a singular matrix. With one subroutine (shared with all other programs) it takes 1343 bytes.

  8. Linintp - linear interpolation between two points. Error handling doesn't allow you to enter x2 smaller than x1, alerts also if you extrapolate. With one subroutine this program takes 1425 bytes.
  9. Tempconv - Converts temperatures from one scale to three remaining scales. You enter the temperature, select the units from a menu, this program displays the temperature converted into the three other scales. This is an example:

    10. Screen of TI-89

    This program, together with one short subroutine (shared with all other programs) is 1427 bytes long (version for TI-89/92/92 Plus).

  10. Crossdot - Vector (cross) and scalar (dot) product of two vectors. You enter components of two vectors, this program displays their magnitudes, vector product, the angle between the two vectors, and the scalar product. In case the vector product is longer than the screen, it is possible to view it from the home screen

    11. Screen of TI-89

    Version for TI-89/92/92 Plus of this program is 1654 long (with one subroutine shared with all other programs).

  11. Biorhythms - There are some reasons to believe that a human body works according to three cycles: Physical, with a period of 23 days, Psychological, with a period of 28 days, and Intellectual, with a period of 33 days. These cycles begin when a person is born and, because they have different periods, every day is a different combination of these cycles. When there is a beginning of a cycle, that day is a "zero" day, in the middle of each cycle there is a "crisis" day. In general, if we represent each cycle as a sinusoidal curve, half of the cycle is positive ("better"), the other half is negative ("worse"). Since the cycles are supposed to add, the combination of these cycles for a given day may be positive, negative, or zero. In this program you enter your birthday, today's date, and the program calculates your age in days, and the phase of each cycle for today. Then, after displaying the numerical results, shows you a graph with all three curves and the total. The vertical line shows today, to the left is one month into the past, to the right - one month into the future.

    Word of caution - although calculating the Biorhythms may be fun, by no means it should be treated as a way to predict the future. You have to remember that the duration of these periods is only statistically correct, which means that for a particular person they may not be 23, 28, and 33 days, but for example 23.1, 27.8, and 33.4 days. In such a case results of the calculations may be totally wrong, especially if a person is older (since the differences accumulate with time). In addition to that, there is no reason to believe that these periods are the same when a person is young and when a person is older.
    What you can do with this program, is to look into your past to see if there are correlations of "crisis" days with days when you caught a cold, had a bad day at work or school, and so on. Do NOT use this program to arrange your normal activities. Have fun.
    Version for TI-92 Plus uses four subroutines (some shared with programs Sunrise, Sidereal Time, and The Moon described above). All this takes 2932 bytes of memory.
    Here is an example for a person born on October 25, 1970:

    12. Screen of TI-89 Screen of TI-89