Testing Woodstocks [quite long] Message #36 Posted by Victor Koechli on 20 Jan 2004, 2:28 p.m., in response to message #35 by linter
They don't have a self test like newer machines, so you have to do it yourself. It's not too difficult:
- Turn it on. Do a few calculations of which you know the results, and see if they come out right.
- Enter -8.888888888 EEX -88 into the display and see if all segments work. Press CLx, then 1111111111 and trace the decimal point. it should always be visible. If both tests are OK, then your display is fine.
- Enter any non-zero number and store it in a register (e.g. press STO 2). Then clear the display (press CLx) and see if you can recall the previously stored number from the register (RCL 2).
- Switch to program mode and press SST. If it's a non-Continuous-Memory-model, or if the memory has been cleared, a HP-25 should display a GTO 00 instruction (13 00) as step 01. I'm not sure about the HP-29C, as I haven't got mine running yet, but it's supposed to show R/S (code 74) by default. If you see anything else, press [f] CLEAR PRGM, the SST again. You should now see the default program step.
- Now press a few keys, like numbers, +, - etc. You will see each command as it is recorded in program memory. Switch out of program mode, press [f] CLEAR PRGM (this resets the program pointer to 00 *if* you're out of program mode!), then go back into program mode and press SST several times. Check if you see the commands you previously entered.
- If you cannot recall a stored number, or if the program steps you enter don't come back, then the RAM is dead.
- Finally, switch into program mode and test the keyboard. Press [f] CLEAR PRGM, then start pressing all directly executing keys several times and see if they register as many times as you press them. The keys you cannot test this way are the ones that need an argument to follow after them to yield a complete command: STO, RCL, GTO, [f], [g], and, on the 29C, GSB. Test these prefix keys by pressing two of them alternatingly and observing if the display registers every key press.
- If you've come that far, things seem quite alright. In any way, leave the calc turned on for half an hour and repeat the tests. Some of them need some time to warm up before they work right! They have a life of their own...
- For the models with Continuous Memory, after doing all the tests, turn them off, wait a few minutes, then turn them on again and check if the memory and program contents are still there.
Hope this helps. Testing procedures for Classics are, of course, similar, except that if a card reader is present (HP-65 and HP-67) , you will have to test it, too, e.g. by writing a program to a card and then reading it back.
Hope this helps a bit! Cheers, Victor
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