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HP-32E with errors ...
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04-29-2021, 10:24 PM
Post: #8
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RE: HP-32E with errors ...
(04-29-2021 06:35 PM)PANAMATIK Wrote: I have an HP-25C, which is still calculating, but shows a similar effect, it produces wrong results when using SIN COS TAN etc. I found, by reading the ROMs and comparing, that only one bit of one instruction was flipped. Hi Bernhard, Yes, I can imagine that just one bit could cause behaviours like this. If I had time, I could play with Teenix MultiCalc, and simulate errors in the ROM, but it would not help - just confirm ...  I will send you a PM regarding your offer, resoldering the old ROM's should not be any problems. BTW, do you know if it is easy to read out the contents from these Spice ROM's? I suspect they are serial ROMs, but checking the schematics, it might work to build a simple reader with a PIC or a Arduino maybe? It would be really satisfying to be able to find the actual fault and repeat the error in an emulator - at least just for fun! Best regards, Thomas [35/45/55/65/67/97/80 21/25/29C 31E/32E/33E|C/34C/38E 41C|CV|CX 71B 10C/11C/12C/15C|CE/16C 32S|SII/42S 28C|S 48GX/49G/50G 35S 41X] |
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| Messages In This Thread |
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HP-32E with errors ... - ThomasF - 04-28-2021, 08:04 AM
RE: HP-32E with errors ... - aurelio - 04-28-2021, 10:55 AM
RE: HP-32E with errors ... - ThomasF - 04-28-2021, 12:33 PM
RE: HP-32E with errors ... - rprosperi - 04-28-2021, 01:26 PM
RE: HP-32E with errors ... - ThomasF - 04-28-2021, 05:50 PM
RE: HP-32E with errors ... - teenix - 04-29-2021, 01:58 AM
RE: HP-32E with errors ... - PANAMATIK - 04-29-2021, 06:35 PM
RE: HP-32E with errors ... - ThomasF - 04-29-2021 10:24 PM
RE: HP-32E with errors ... - PANAMATIK - 04-30-2021, 01:55 AM
RE: HP-32E with errors ... - ThomasF - 05-27-2021, 08:45 AM
RE: HP-32E with errors ... - PANAMATIK - 05-28-2021, 09:07 AM
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