<br />-What are the undocumented modes for the GPS 45/40/38/90/89?<br /><br />Globe spin rate and direction:<br /> Go to the map display. Then press the OFF button for 1-2 seconds. The <br /> globe will still be on the screen and you can change the speed with the <br /> up/down buttons and the direction of rotation with the right/left buttons.<br /> Press any other button to return to normal mode.<br /><br />Test screen:<br /> Hold down ENTER while pressing on the POWER button.<br /> Invokes button test screen and displays labeled:<br /><br /> SNR Signal to Noise Ratio?<br /> DRIFT of FREQ below<br /> FREQ apparently this is a 16 MHz internal clock<br /> TEMP degrees Celsius <br /> BATTERY voltage in hundredths of Volts<br /> EXTERNAL external power connector voltage in hundredths of Volts<br /> TIME Universal Coordinated Time without local offset<br /><br /> Press LEFT or RIGHT arrows to adjust contrast.<br /> Press ENTER 2 times to get an all black screen, press ENTER again for cool <br /> exploding rectangles on the display. Press ENTER again to exit this mode.<br /> Hold down OFF button to exit test screen.<br /> Also turns beep on if you had it off!<br /><br />Full reset and memory clear:<br /> Hold down MARK while pressing on the POWER button (CLEARS MEMORY!!!).<br /> DO NOT TRY THIS UNLESS YOU ARE WILLING TO LOSE ALL SAVED INFO!!!!!!!!!! <br /> Waypoints, Track, Routes and more will all be gone. I would not do this <br /> unless my GPS unit was having serious problems (and then only as a last <br /> resort attempt to fix it before sending it in for repair)! It returns<br /> all settings to initial factory defaults.<br /><br />Diagnostics mode:<br /> To get into this mode, quickly after turning on the power (while the globe <br /> is still spinning), press all 4 arrows one at a time (in any order).<br /><br /> 2 or 3 digit numbers are added to many screens. Reportedly they are the <br /> process stack depth. |<br /><br /> The signal strength bars are initially hollow. They become solid apparently<br /> when some specific data has been downloaded from the satellite.<br /><br /> The number in the bottom right of the satellite screen (usually something<br /> like 1.3 or 4.2), looks like an indication of the geometric degradation of<br /> [precision] (GDOP). It varies with the number and location of satellites <br /> being received, being lowest when a group of satellites scattered widely over<br /> the sky are present, and highest for a cluster of satellites, or when the<br /> received satellites are all in a straight line. It also seems to vary in<br /> step with the "accuracy" number normally displayed in the top right.<br /> Contributed by
proach@cais2.cais.com (Peter Roach) <br /> <br /> The internal temperature in degrees Fahrenheit is added to the position <br /> screen to the right of the time. <br /><br /> A "DIAG" option is added at the bottom of the menu screen. The following<br /> is displayed on the DIAG screen: <br /><br /> Battery voltage in hundredths of volts.<br /> Elapsed time (can be zeroed by pressing ENTER).<br /> Screen can be paused by pressing MARK.<br /> Looks like there is a lot of internal software debugging info.<br />
