HP Forum Archive 06

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41cx synthetic and over clock Message #1 Posted by Miguel(Denver) on 20 June 2001, 1:40 p.m. I am rediscovering my cx...it died sometime ago and my 11c works for all that I use a 'calculator' for. 11c stories at a later date. 1) I was unaware of the ability to overclock...does this apply to the late model 41cx "no-nut"? details or location of said details would be cool. 2) Which cap holds the memory...it seems that a bridge on this cap With Out the Batteries would be quite effective at resetting the machine. 2) Does the 41cx still have the 'bugs' needed to make synthetic programming work? 3) I assume that the right digging on this site will hepl me get started with synth-(prog.http://www.hpmuseum.org/prog/synth41.htm) 4) There seem to be at least 2 important modules for this... the PPC and the one from germany, are these available at all? thanx Miguel

Re: 41cx synthetic and over clock Message #2 Posted by Tony Duell on 20 June 2001, 2:21 p.m., in response to message #1 by Miguel(Denver) In the halfnut, I believe that you need to discharger at least the 470uF electrolytic capacitor, and maybe the 33uF one as well to remove the memory supply. Certainly discharging both of them should do it. I'd use a 1k resistor rather than just shorting them out, though, to avoid damage from a possible high-current spike. 2) As far as I know, synthetic programming works on all 41s, including halfnuts and CXs. The important 'bugs' (the ability to edit a key assignment register from the keyboard, and the fact that some combinations of prefix and postfix bytes do interesting things) are there on all HP41s. 4) There were several ROMs to help with synthetic programming -- the most famous being the PPC ROM, the CCD ROM (that's the 'german one' you mentioned) and the UK ZenROM. None of them are essential -- you can do synthetic programming with a bare HP41. Conversely, you can also do it the way I do it (I have none of the above ROMs), namely either creating barcodes of programs with synthetic instructions on another machine and reading them with the wand, or creating the program in binary on another machine and downloading it using e.g. the HP82164 RS232 interface and the Extended I/O function INP. There are many ways to do it...

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