HP-71b - Future "SD-RAM" Module - viable ?

[Maximilian Hohmann]

Hello!

(09-07-2022 02:14 PM)mfleming Wrote:  BTW, with regard to the thread title, a microSD card or any flash device for that matter, would not be ideal for continuous use even as a ROM. Flash draws tens of mA current in use and so would be best for secondary storage.

When I saw this thread and the photo in the first posting I thought: Now this must be the most clever idea of the month! Use an SD card just as you would use a magnetic card (if you were lucky enough to find a card reader and cards). Plug it into the card reader, use the standard commands of the calculator for reading and writing and pull it out again.
128MB SD cards can be found for less than 1$/Euro/GBP on the internet, a lot cheaper than the few remaining magnetic cards.

What would it matter how many Milliamperes this cards draws during the few seconds that it is connected? The HP-71B has four (rechargeable) AAA batteries in it's belly, this is plenty for filling thousands of SD cards!

I would be more than willing to upgrade one of my HP-71Bs to a card reader replacement that accepts SD cards in lieu of magnetic cards. Unfortunately my embedded programming skills do not go beyond Arduino and this is clearly not sufficient here. A solution that requires a "PIL-Box" and some "Pil-software" running on either Windows or Linux (neither of which I have installed anywhere) and "LEX"-files of some kind in EPROM Modules is over-over-overkill for what is actually required here. But maybe I am just thinking too simplistic?

Regards
Max