|Re: Yeap! And...|
Message #16 Posted by Nelson M. Sicuro (Brazil) on 19 July 2004, 12:50 p.m.,
in response to message #15 by Vieira, Luiz C. (Brazil)
I think that the LCD must be the original, I don't know any of-the-shelf LCD display of the same size of the Voyager's. I found some COG character modules that *almost* fit inside the case, but you'll need to "shape" the case accordingly. I'm planning a entire PCB replacement with only one chip - CPU from TI (MSP430F449, with segment LCD controller) and maybe one RS-232 level converter, all operated with the same 3V coin cell of the China made 12Cs.
About the software, as it has FLASH ROM, you can run an emulation OR any other modification you want on the original ROM (more ROM up to 32K(??), more RAM up to 1KB+1KB for the system) or any other software you want on it - even with realtime clock. The battery can lasts years with one of those MSP430 from TI, search for its datasheet to see its (very) low power needs... This CPU costs < US$15 on the market.
I only need one these new HP-12C to "play" with - I'll not sacrifice my USA made flex-PCB near-mint 12C!! It only need to have a case/keyboard and LCD intact, the CPU can be "toasted" ;)
I'll try to do it first with one prototype header PCB for the CPU and manually wired on the LCD/keyboard contacts to begin the OS/emulation develompent. Maybe I can get some help from Erik Smith for the NUT emulation?? ;)
Anyway, I haven't yet the prototype PCB, only the bare 100-pin SMD chip and some ideas...
I accept any help that the comunity can give!
P.S. About the internal pictures I promissed you - I was without internet on my home on the weekend, I'll manage to sent to you tonight.