HP Forum Archive 12

[ Return to Index | Top of Index ]

What is this switch on a 55 ? Message #1 Posted by Renato on 21 Apr 2003, 1:16 a.m. Have you seen it ? http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3019993514 The Museum photos do not show a switch. The unit on auction shows it clearly, and it does not look like it is an adaptation.

Re: What is this switch on a 55 ? Message #2 Posted by Katie on 21 Apr 2003, 1:47 a.m., in response to message #1 by Renato It looks like some sort of custom modification to me. But I've got no idea as to what function that swtich would serve unless it's to replace a broken on/off or prog-timer-run swtich.

It's at least tricky Message #3 Posted by Vieira, Luiz C. (Brazil) on 21 Apr 2003, 1:56 a.m., in response to message #1 by Renato Hello, Renato; I have an HP55 and I searched for any possible correction/modification at the same position the switch is, and I saw no marks in calculator's case. I did not open my calculator to see what's closer to the extra switch, but i can tell you in that same position there is nothing, and the closest internal component is the keyboard. The mainboard ocupies the area "under" the backlabel only. Maybe it is some sort of very well know modification, and one of our friend will come to help soon. Well, I have no idea of what could it be, and it seems the sellers have no idea of what could other switches be too, so I'd not create perspectives under a possible answer. May the buyer be a contributor so we can ask him about it... {}s. Luiz C. Vieira

Re: What is this switch on a 55 ? Message #4 Posted by Ellis Easley on 21 Apr 2003, 6:03 p.m., in response to message #1 by Renato Maybe it is for the perennial programmable calculator mod - speedup. My HP25 with working memory that I finally bought was a little flakey in the memory when it arrived. I found that it's capacitor had been changed to speed it up! HP41 speedups usually included a switch to select normal speed for speed-dependent operations and the 55 timer function would be such an operation. Of course, the 55 has a crystal and not an LC tank. The switch might select between two crystals, or between a crystal and an LC tank, or it might connect something to the crystal to make it oscillate at a harmonic.

Re: What is this switch on a 55 ? Message #5 Posted by David Smith on 22 Apr 2003, 5:13 p.m., in response to message #1 by Renato One (remote) possibility is that it is a switch to blank the display during long program runs to save battery power. I know of a couple of machines that were modified to do this, but am fairly sceptical about just how much extra battery life you got by doing this.

Re: ... blanking LED's to extend battery life? Message #6 Posted by Paul Brogger on 22 Apr 2003, 7:25 p.m., in response to message #5 by David Smith For my part, since I've been playing with the new battery pack in my HP-97, I'm not so skeptical . . . I've been running the batteries down periodically for a full reccharge, and to do this I run a fun little idle loop. As the power falls, the "low power" LED comes on gradually. I noticed that, early on, the low power indicator flashes in synch with whatever the display happens to be doing, until the power reaches a greater degree of lowity ( ;^) er, rather, a lower level) at which fuzzy point it stays on continuously. This indicates that, during that transition period, the power drain of the display is enough to take the voltage below some threshold, and when the display blanks, the voltage is restored somewhat. Unless I'm missing something, the LED display must be a significant (if not the dominant) portion of a classic's / woodstock's / spice's power usage. (That is, as opposed to the digital circuitry, and aside from the card reader and printer.)

Re: lowity Message #7 Posted by Ellis Easley on 23 Apr 2003, 2:39 a.m., in response to message #6 by Paul Brogger Do you possibly mean "lowicity"? Here are a couple of words I learned from a book about sheet metal work: "rollation" which I think means either wrapping sheet metal around a piece to get an idea of the perimeter, or rolling the edge of a piece across a flat surface to determine the perimeter; and "trimulation" which means just what it sounds like - cutting it bigger and trimming it to size!

Re: Yeah! "Lowicity" . . . That's it! Message #8 Posted by Paul Brogger on 23 Apr 2003, 10:07 a.m., in response to message #7 by Ellis Easley Sometimes I find myself typing me into a verbal corner, and despite the existence of a "backspace" key, I desperately want to find a way to make it work . . . Coining a new word on-the-spot often helps! (I suppose I would have made a lousy lead guitarist.) At our office for quite a while, we monthly awarded a certificate and an engraved addition in a place of honor on a plaque, to the person who had come up with the best word. Some winners: "frivial" (frivilous and trivial), "relieviate" (to simultaneously relieve and alleviate), "versionary" (the person envisioning the next version). (And I do like "lowicity" better than "lowity" . . . )

Re: Yeah! "Lowicity" . . . That's it! Message #9 Posted by Ellis Easley on 23 Apr 2003, 8:18 p.m., in response to message #8 by Paul Brogger Do you have "Chicken Express" in your town? Or any chicken place that offers livers and gizzards. I love livers, hate gizzards but I think they should offer a combination plate and call it "lizzards"! Kids would order it just to play with them like toys.

Re: Yeah! "Lowicity" . . . That's it! Message #10 Posted by Trent Moseley on 23 Apr 2003, 10:09 p.m., in response to message #9 by Ellis Easley Ellis, Are you trying to start a new franchise? tm

Re: Yeah! "Lowicity" . . . That's it! Message #11 Posted by Ellis Easley on 23 Apr 2003, 10:49 p.m., in response to message #10 by Trent Moseley Yeah, carry out reptile dishes! I tasted rattlesnake when I was an Explorer scout and I've had crocodile at a Cajun joint. Then there's frog legs - are those reptile? I think they are amphibians.

Re: Yeah! "Lowicity" . . . That's it! Message #12 Posted by yan can cook on 24 Apr 2003, 2:18 p.m., in response to message #11 by Ellis Easley and you can use chicken in each recipe.

Re: Yeah! "Lowicity" . . . That's it! Message #13 Posted by David Smith on 24 Apr 2003, 5:42 p.m., in response to message #12 by yan can cook I prefer "long pig"...

Re: Yeah! "Lowicity" . . . That's it! Message #14 Posted by Ellis Easley on 24 Apr 2003, 6:58 p.m., in response to message #13 by David Smith What's that? A hot dog?

[ Return to Index | Top of Index ]

Go back to the main exhibit hall