Upgrading the ROM from SD card
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From: Horszowski on 18 Sep 2009 22:38 Someone please refresh my memory. I remember there was some confusion (for me anyway) on upgrading the ROM from an SD card. In order to do so, the card must be formatted with FAT, however the calculator will only format to FAT cards smaller than 32 meg and FAT32 for 32 megs and larger, therefore you could only upgrade the ROM from an SD card 32 megs or larger if that card was formatted to FAT by the PC. Is this correct or am I missing something?. Thanks
From: David Brigada on 21 Sep 2009 09:32 FAT16 should work up to 2GB. -Dave Horszowski wrote: > Someone please refresh my memory. > I remember there was some confusion (for me anyway) on upgrading the > ROM from an SD card. In order to do so, the card must be formatted > with FAT, however the calculator will only format to FAT cards smaller > than 32 meg and FAT32 for 32 megs and larger, therefore you could only > upgrade the ROM from an SD card 32 megs or larger if that card was > formatted to FAT by the PC. Is this correct or am I missing > something?. > > Thanks
From: Eric Rechlin on 21 Sep 2009 10:28 "Horszowski" <horszowski(a)gmail.com> wrote: > I remember there was some confusion (for me anyway) on upgrading the > ROM from an SD card. In order to do so, the card must be formatted > with FAT, however the calculator will only format to FAT cards smaller > than 32 meg and FAT32 for 32 megs and larger, therefore you could only > upgrade the ROM from an SD card 32 megs or larger if that card was > formatted to FAT by the PC. Is this correct or am I missing > something?. That's exactly right. Don't bother formatting the card with the calculator. Use a PC to make sure you always format it with FAT16. FAT32 has less "slack" space (wasted space at the end of files due to cluster boundaries), so you can fit more small files on a card with FAT32, but given the limitations of the calculator I can't see how anybody could reasonably approach the FAT16 limit with the 2GB cards that are the smallest widely available size today. The benefits of FAT16 are better performance (the calculator turns on faster because it doesn't have to scan as many clusters when it is checking the SD card at powerup) and ROM upgrade support. I have no idea why the calculator defaults to FAT32 for 32MB+ cards. I guess you'd have to ask Kinpo, because it makes no sense to me. Regards, Eric Rechlin
From: Iskon News on 28 Sep 2009 18:23
> That's exactly right. Don't bother formatting the card with the > calculator. Use a PC to make sure you always format it with FAT16. > > FAT32 has less "slack" space (wasted space at the end of files due to > cluster boundaries), so you can fit more small files on a card with FAT32, > but given the limitations of the calculator I can't see how anybody could > reasonably approach the FAT16 limit with the 2GB cards that are the > smallest widely available size today. The benefits of FAT16 are better > performance (the calculator turns on faster because it doesn't have to > scan as many clusters when it is checking the SD card at powerup) and ROM > upgrade support. > > I have no idea why the calculator defaults to FAT32 for 32MB+ cards. I > guess you'd have to ask Kinpo, because it makes no sense to me. > > Regards, > > Eric Rechlin I belive i can answer your question: -we can all agree that most files are small (around 1 to 5 kiBs) -you could run some statistics, but even without statistics (just by examinig my caluclators card) it looks that way Knowing this the optimal "allocation unit" (sector) size would be "as small as can be" (512 Bytes). That way we get minimum slack space that you spoke of AND calculator handles less data when accessing SD at once (in short: works faster in our case) So if we keep our "sector" size at 512 bytes using FAT (16 bit) we can use up to 32 MiBs. (64k sectors of 512 bytes each) ofcourse we could use 1kiB sectors (which ist still reasonable) and use up to 64 MiBs cards NOTE: for example if you're accessing a variable of several nibbles you calculator (at lower level) would move around 1 kiB of data which is about twice more than it would using 512 byte sectors. And using 512 byte sectors is actualy about 80 times more than your "usefull" data. At the time when HP requested FAT32 support somone probably mentioned that 512 byte sectors should be prefered KINPO did the math and thats why it works that way MORE TO SD: although i'm still using my 16 MiB SD and i still find it to be more than enough for all my needs i played a bit with 1 GiB microSD with adapter to SD. AND... it works -so i made some tests with FAT32 1. formated the card with 512 bytes per sector ended up with 1 M+ sectors, the startup delay was about 3 or 4 seconds (i didnt bother to time it accurately it was unacceptable to wait for calculator to switch on for so long) BUT then i realized that when i put the card in to card reader on my PC there is similar delay for card to be recognised and mounted as a drive. Much stronger computer made me realize that nothing is wrong with the calculator, and there should be other ways to work this out. 2. i played and tested with sector size and sector count and i realized that startup delay is not bothering as long as the total number of secors was reasonable My conclusion: i would prefer for my card to be 32 or 64 MiBs and even if i didn't have one i would format the card so the startup time would be unnoticable and calculator would not handle massive overhead sectors when accessing SD. (even if i loose much of the original capacity, you would loose much more in "slack" and at the same time it would work slower, greater startup delay and so on...) I mentioned many times before and i still belive it's right: Port0 -keep your RAM clean (for run-time memory) Port1 for temporary stuff Port2 (flash) for libraries <- the ones i actualy DO frequently use (not every single one that i get) SD card for storage and ALL other (like hard drive on your PC) I wrote a simple small startup program to recall important things and parametters form SD, like flags and stuff and configures my calc the way i wanted it for me. That way even when the calc gets locked up, reset, reboted, restarted... whatever nothing is changed it's all the way it was, Also when i put the card into other calculator i just copy STARTUP to "home", restart (ON-C) and the calculator is exactly like i want it to be. At todays prices for flash cards sharing a card between camera, cellphone or any other device is nonsense. Very large and sophisticated programs, games etc. can be done so that everything is read (recalled) from SD, executed and processed "on demand" or "cached" in RAM as much as your environment allows and requires. In general with a little care and dedication to given (working) environment the possibilities are truly endless. (with no changes at all, just an adjustment in our point of view) (just some thoughts from me :-) Regarding topic: i prefer to update the ROM using a cable :-) Regards, manjo http://fly.srk.fer.hr/~manjo/openfire/ |