Texas Instruments TI-92 Plus Graphing calculator

Description

This is realy a awesome calculator. It's realy well thought out and it took me very little effort to get going. What I like most about it is the ability to just enter equations in much the same way as you would write them on paper. I also have a HP-48, which I use a lot. But when entering large equations I always have to stop and think about how to enter the bits and pieces. On the TI-92 I just type away, and it just figures out how to get to the desired result. Fabulous!
The only slightly bad thing about it is it's size. I wouldn't like to have to carry it to school or work every day.

Real-time clock became available in OS Version 2.09.

Performance index

Performance differs fastly depending on the settings used. In exact mode the performance index is only 9, in approximate mode it jumps to 46. The performance index was calculated using this code (-> is used for the STO-button character):

perf()
Prgm
100->n
While n>0
	10->l
	While l>0
		l->x
		x+1->x
		x-4.567E-4->x
		x+70->x
		x-69->x
		x*7->x
		x/11->x
		l-1->l
	EndWhile
	log(x)->x
	sin(x)->x
	sqrt(x)->x
	sqrt(x)->x
	n-1->n
EndWhile
Disp x
EndPrgm

Execution time was 73 second when n=100. The resulting index is (34×n)/73 = 46.

Self test / diagnostic menu

The TI-92 has an undocumented self test menu. To enter this, go to the HOME page (diamond-Q), press F5 and then press diamond and ( together.



A copyright notice appears:

Copyright © 1998 Texas Instruments, Inc
Copyright © 1998 Soft Warehouse, Inc.
Version 2.03, 12/08/1999

Now press S to view the test menu:

2.03, 12/08/1999
1) FLASH TEST
2) RAM TEST
3) KEYBOARD TEST
4) LCD TEST
5) IDD OFF TEST
6) LOW BATTERY TEST
7) HI VOLT CONTRAST TEST
8) LO VOLT CONTRAST TEST
9) OSCILLATOR TEST
0) RETURN

Pressing the number key corresponding to the test number invokes that test.

Flash test

Displays Checking BASE CODE and returns to the main menu. What it does exactly, I don't know.

RAM test

Displays a flashing pattern of vertical lines. Press ON to exit the test, this exits the test menu as well. All factory defaults have been restored at this point.

Keyboard test

Displays a pattern of black rectangles to match the position of keys on the unit. Pressing a key that corresponds with a rectangle will turn that rectangle hollow (if the key functions properly). Press the ON key last to return to the main menu. Pressing the ON key before last results in an error.

LCD test

Displays a sub-menu

1) 1 Bit checkerboard
2) 8 Bit checkerboard
3) All ON
4) All OFF
5) Box pattern
6) Auto cycle
7) Return to main menu

These test display various test patterns to verify the proper functioning of the display.

IDD OFF test

The display goes blank (empty). It might be testing the auto-off function, but I'm not sure. Pressing the ON key returns to the main menu, no other key seems to do anything.

Low battery test

Displays Level 3 detected on my unit. Pressing ON displays Battery Test FAILED. Pressing ON again displays Press ON to continue. Press ON again to return to the menu. My unit does not display a battery low warning, I don't know why this test failes. If you have suggestions, please drop me a line at the bottom of this page.

Hi volt contast test

Screen goes blank. Press any key to continue.

Low volt contrast test

Screen goes black. Press any key to continue.

Oscillator test

Displays (test takes about 5 seconds):

Oscillator Test
 DATA= 0003C932
 DATA= 00000058

 TEST PASSED

Probably tests clock oscillator, although I'm not sure. Press any key to continue.

Return

Exits the test menu and may do a complete reset, depending on the tests you performed. Press 2ND and ESC (QUIT) to return to the main application page if the unit does not reset automatically.

According to sources this self test also works on the TI Voyager 200.

Links

education.ti.com - official TI-92 site
ticalc.org - excellent source of info and software for all TI models
TI-92 help - help with mathmatical problems
Turbo92 - overclocking the TI-92 to 2-4 times normal speed
ocf.berkeley.edu - TI-92 games
TI-92 Manual (Guidebook) - slow connection!

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