Re: HP7B-CL Message #30 Posted by Diego Diaz on 19 May 2012, 1:29 p.m., in response to message #22 by Frido Bohn
Hi Frido, all,
Although I actually began working on such a "Clonix-71" project (for the front ports) a couple of years ago, I didn't success in doing the prototype work as expected.
Main reason for the fail was the big differences in power management between 41C and 71B, which causes the microcontroller to be running at least half of the time (even while the 71 is OFF), this is unpractical in terms of battery drain.
On the other hand, as it has already been pointed out in this thread, the HP-71B has an extremely short list of ROM modules, and there are several devices (mostly for the card reader port) that allow EPROM's to be used. Furthermore, cases for such modules will be at least ten times more difficult to obtain than those for the HP-41... :-(
Then it comes Hans' FRAM71 project, which uses RAMTRON's non volatile memory paralell type quite like the NoV's use the serial type, therefore it can be considered quasi-ROM.
In my opinion this is "the way" to go, and will also join the waiting list for one of these FRAM71 modules when the first production run arrives... :-)
Enjoy your HP's!
Diego.
Edited: typos.
Edited: 19 May 2012, 2:33 p.m.
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