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Observations: 2GB SD card with the 50g. - Printable Version

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Observations: 2GB SD card with the 50g. - Ken Ratkevich - 12-05-2006

Yeah, I know ... extreme overkill. However, this is what I've noticed thus far:

- File Manager reports "961984KB".

- Attempting a FAT32 format (ROM 2.09) fails.

- Windows XP recognizes the card as a 2GB drive.

- Moving objects to/from the SD card works fine.

Remarks anyone?


Edited: 5 Dec 2006, 8:29 a.m.

Re: Observations: 2GB SD card with the 50g. - Gene - 12-05-2006

The filer can only report the size as slighly under 1GB. Don't worry, a 2GB card is ok with the 49g+/50g. All 2GB is there, but the filer can't report a size that large.

Small nit :-)

Re: Observations: 2GB SD card with the 50g. - James M. Prange (Michigan) - 12-05-2006

Definitely overkill, and note that with a large card, there can be an annoyingly long delay after pressing the ON key before anything is displayed. The turn-on delay can be reduced by formatting the card with larger (and therefore fewer) clusters, or formatting it FAT16 (if FAT16 can be used with that capacity). Yes, I know that formatting to larger clusters typically results in more slack space, but how much capacity will you actually use for a calculator card?

I think that the file manager problem has to do with how many bits of the available capacity value it uses for reporting. If it uses a bint (system binary integer) for the value, then that effectively limits the wordsize to 20, and the largest capacity that could be reported correctly would be 1048575. My guess is that it's reporting the capacity modulo 1048576. I expect that if you put enough on the card to get the available capacity down to 1048575 or less, then it will be reported correctly.

I guess that they weren't expecting cards this big to be used when they designed the system.

Remember that the 49g+ was introduced in 2004, and the 50g is basically a 49g+ with a better keyboard, improved colours, the serial port and battery wired to a connector, another AAA cell, the ability to get power from the USB connection, and a few tweaks to the operating system to enable the new hardware features and use of the new model number. The 49g+ and 50g can even use the same ROM.

Regarding the formatting problem, I can format a 1GB card with the 49g+, but there might be a limit to the capacity that it can format; I can imagine such a limitation stemming from the maximum value of a bint.

As long as the card can be formatted correctly with a PC, I wouldn't lose any sleep over it.

My advice is to use a smaller card with the calculator and save the big one for other uses; 64MB and smaller cards don't cost much. Many of the small cards that came with some video cameras, cell phones, and so on aren't used, so someone may have one that he's willing to give you.

For more information, try a search from http://groups.google.com/group/comp.sys.hp48.


Re: Observations: 2GB SD card with the 50g. - Maximilian Hohmann - 12-06-2006


Yeah, I know ... extreme overkill.

Remarks anyone?

Just one remark (and I even used an hp calculator to come to this result ... ):

If you manage to type one character per second into your calculator on average (I take longer...), and you do this for 24 hours a day with no rest, then you will have filled your card for the first time after 65 years and 291 days :-)

With classic hp calculators, there might even be a chance that the keyboard lasts that long - but on a new one, who knows!

Greetings, Max

Re: Observations: 2GB SD card with the 50g. - James M. Prange (Michigan) - 12-07-2006


An alternative explanation would be that the filer's display field is limited to 8 characters; that is, perhaps it's getting 1961984 for the number of KB but displaying it as 961984KB due to a limitation in the size of the display field, so what you'd see would be the available capacity (in KB) modulus 1000000.


Edited: 7 Dec 2006, 8:39 p.m.