WARNING: Invoking the test described below may result in the clearing of data memory, program memory, and mode settings.The HP-48 series calculators have built-in internal, display, and keyboard test functions. These functions are accessed by pressing and holding the ON key then pressing one of the keys on the top row of the keyboard.A continuous internal/display test is performed by simultaneously pressing the ON key and the E key (the fifth key on the top row). This test will cycle through CPU, display, IROM, and IRAM tests. "OK-48" is briefly displayed before starting over. This cycling test is cancelled by simultaneously pressing the ON key and the C key (the third key on the top row).Individual tests can be performed by simultaneously pressing the ON key and the D key (the fourth key on the top row). No menu is displayed, however a vertical line is displayed down the center of the display. Most of the keys in the top five rows of the keyboard have a unique test assigned to them, however only those tests associated with the top row of keys will be discussed. Simultaneously press ON and C (the third key on the top row) to exit the individual test mode.A: SPD. This appears to be a CPU test.B: Display. This display test generates a series of test patterns. A key must be pressed to sequence through the seven test patterns.C: IROM. This test tests the internal ROM of the calculator. If the test completes successfully, "IROM OK" is displayed.D: IRAM. The internal RAM of the calculator is tested. If the test completes successfully, "IRAM OK" is displayed.E: KBD1. This test requires you to press each key from left to right, from the top row to the bottom row. The calculator beeps as each key is pressed. If a key is pressed out or order, a different beep is heard and a five-digit hexadecimal number will be displayed. Upon successful completion of the test, the message "KBD1 OK" is displayed.F: KBD2. This test appears to test the keyboard scan lines, and requires only a few keys to be pressed. The following keys, outlined in yellow in the illustration at the right, must be pressed in the following order to successfully complete this test: B, CST, Cursor-Left, yx, Backspace, Alpha, 4, 2, SPC. "KBD2 OK" displayed upon successful completion of the test.
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Survey Photos by Tag or CategoryEarth's Largest Survey Photos Collection
Since 2007, Land Surveyors around the world have shared their best Surveying Photos from the field. Inside this collection you can transport yourself to virtually any location on Earth and see how Land Surveyors work, types of equipment being used and environmental challenges associates with being a land surveyor in that location.
Location Based Chapter Hubs also have photos specific to the locations they represent. You can use our Surveyor Apps for quick sharing of your photos from the field.
Note: Members who have uploaded their photos of surveying to this collection can also move their photos to location based hubs. To see how, follow this tutorial.
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