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Is 50g good or crap?
02-28-2018, 10:29 PM
Post: #55
RE: Is 50g good or crap?
Best calculator I've ever had and that's saying a lot considering I have an HP-41 and all the calculators older than that plus a selection of blister-packed ones. I like mine well enough that when they announced the EOL, I bought a case of them even though I'm retirement age. True the old ones are bullet (and probably tank) proof but dang, the HP-45 was $495!!! HP obviously had to scrimp on something to keep the price reasonable and I think they made pretty good choices. I don't like their decision of putting the Saturn on an ARM chip but I can live with it.

The big hairy zit on the nose of this calculator is HP's decision to gimp the IrDA port. The academics claimed that people would "cheat" if the IrDA actually worked. The transmit port is so gimped that it'll barely drive the printer when the windows are in contact.

Being a design engineer, I just could not let this situation prevail. So I designed a MUCH improved IrDA. It will hit my calculator from 6-8 ft away. Unfortunately this wasn't the easy job I thought it would be. I was hoping that a change in resistor or something similar. Faint wishes. When HP gimped the calculator they did so with malfeasance in their hearts.

They had a special IrDA transceiver made just for the IrDA capable devices. It looks just like an IrDA transceiver you might see in a TV remote or something. But with 5 volts on it, I could barely see it with my IR-sensitive camera.

Not wanting to risk one of those COB blobs from where the drive signal came from, I designed a board to fit in place of the IrDA thing. I had to sacrifice the transmit side so to fit everything in. I used the most efficient IR LED I could find and switched it with the lowest Rds power fet I could find.

This mod works extremely well but I'm not so sure anyone else would want to risk their calculator unless they had a box of spares like me.

John
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Messages In This Thread
Is 50g good or crap? - lemontea - 05-01-2014, 02:33 AM
RE: Is 50g good or crap? - Tugdual - 05-01-2014, 02:43 AM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 02:54 AM
RE: Is 50g good or crap? - Jim Horn - 05-01-2014, 03:30 AM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 03:40 AM
RE: Is 50g good or crap? - HP67 - 05-01-2014, 07:19 AM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 07:37 AM
RE: Is 50g good or crap? - Nigel (UK) - 05-01-2014, 09:27 AM
RE: Is 50g good or crap? - peacecalc - 05-01-2014, 10:21 AM
RE: Is 50g good or crap? - Manolo Sobrino - 05-01-2014, 10:50 AM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 10:31 AM
RE: Is 50g good or crap? - Alvaro - 05-01-2014, 10:48 AM
RE: Is 50g good or crap? - jebem - 05-01-2014, 11:12 AM
RE: Is 50g good or crap? - Alvaro - 05-01-2014, 11:32 AM
RE: Is 50g good or crap? - cutterjohn - 05-01-2014, 12:35 PM
RE: Is 50g good or crap? - jebem - 05-01-2014, 11:02 AM
RE: Is 50g good or crap? - Alvaro - 05-01-2014, 11:57 AM
RE: Is 50g good or crap? - jebem - 05-01-2014, 01:09 PM
RE: Is 50g good or crap? - Alvaro - 05-01-2014, 01:15 PM
RE: Is 50g good or crap? - Egan Ford - 05-01-2014, 10:41 PM
RE: Is 50g good or crap? - jebem - 05-02-2014, 02:05 PM
RE: Is 50g good or crap? - Steve Simpkin - 05-02-2014, 06:25 PM
RE: Is 50g good or crap? - Thomas Radtke - 05-03-2014, 06:37 AM
RE: Is 50g good or crap? - jebem - 05-03-2014, 09:58 AM
RE: Is 50g good or crap? - Thomas Radtke - 05-03-2014, 11:10 AM
RE: Is 50g good or crap? - Dave Britten - 05-01-2014, 12:45 PM
RE: Is 50g good or crap? - Egan Ford - 05-01-2014, 10:44 PM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 10:47 PM
RE: Is 50g good or crap? - Egan Ford - 05-01-2014, 11:09 PM
RE: Is 50g good or crap? - jebem - 05-01-2014, 01:48 PM
RE: Is 50g good or crap? - peacecalc - 05-01-2014, 04:43 PM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 09:50 PM
RE: Is 50g good or crap? - walter b - 05-01-2014, 10:04 PM
RE: Is 50g good or crap? - Egan Ford - 05-01-2014, 10:55 PM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 10:37 PM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 10:45 PM
RE: Is 50g good or crap? - lemontea - 05-01-2014, 11:07 PM
RE: Is 50g good or crap? - Egan Ford - 05-01-2014, 11:25 PM
RE: Is 50g good or crap? - lemontea - 05-02-2014, 12:38 AM
RE: Is 50g good or crap? - jracca - 05-02-2014, 04:17 AM
RE: Is 50g good or crap? - lemontea - 05-02-2014, 06:52 AM
RE: Is 50g good or crap? - Steve Simpkin - 05-02-2014, 09:11 AM
RE: Is 50g good or crap? - lemontea - 05-04-2014, 02:09 AM
RE: Is 50g good or crap? - jebem - 05-04-2014, 05:58 PM
RE: Is 50g good or crap? - lemontea - 05-05-2014, 12:02 AM
RE: Is 50g good or crap? - Egan Ford - 05-08-2014, 08:39 PM
RE: Is 50g good or crap? - cutterjohn - 05-09-2014, 04:59 PM
RE: Is 50g good or crap? - Egan Ford - 05-09-2014, 05:23 PM
RE: Is 50g good or crap? - walter b - 05-09-2014, 05:24 PM
RE: Is 50g good or crap? - HP67 - 05-05-2014, 06:10 AM
RE: Is 50g good or crap? - Manolo Sobrino - 05-08-2014, 03:52 PM
RE: Is 50g good or crap? - lemontea - 05-10-2014, 02:05 AM
RE: Is 50g good or crap? - neonjohn - 02-28-2018 10:29 PM



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