MobileRead Forums - View Single Post - 903 microSD write fails on PocketBook 903

LoneTech · 01-09-2011, 11:53 PM

Of course I have read the manual. I mentioned it in the review, including little niggles like how it shows the wrong model, wrong keyboard, menus that do not exist etc. It's also poorly translated. Thanks for suggesting it, though, as it allowed me an opportunity to find that PDF text search in pdfviewer is useless. In AdobeViewer, it merely hangs when I ask it to continue searching, but did find words. I really did not expect that.

The manual mentions the slot exists, that it takes MicroSD up to 32Gb (some of us would spell that GiB to avoid confusion, as b is frequently used for bit and G is 10^9).. which of course means microSDHC, a different protocol. SD only goes up to 2GB, formally. My card happens to be SDHC although it is only 2GB, but supports both protocols. There's no mention of the speed class there, nor on the box - only in this forum.

Another document I have been reading is what little of the SD specification that is public. Conveniently, this includes no way of confirming what the Class ratings even mean. The common hypothesis is that it means linear recording speed in MB/s, which in the specification is carefully outlined; that means writing entire eraseblocks, a behaviour a video camera can easily apply. A computer, not so much.. unless you pass low level knowledge of the card to it and accept abysmal performance (none of the major OSes do this). The only other difference with higher class cards appears to be an optional write rate informational command, that could be used to detect slow cards. If you use that, naturally you'd assume a slow card if the command fails, so if they do, and require faster cards (which they should not), there's no excuse to not show a warning.

The fact of it is, the SD slot isn't working as advertised, and instead of escalating this issue to the maker of that part, PocketBook is filing it as "probably doesn't happen with another card". That the failure mode is unacceptable as well is also glossed over.

I'm sorry if I misunderstood your post. I still can't quite figure out what its purpose was.

01-09-2011, 11:53 PM	#19
LoneTech Zealot Posts: 135 Karma: 7767 Join Date: Oct 2010 Device: PocketBook Pro 903	Of course I have read the manual. I mentioned it in the review, including little niggles like how it shows the wrong model, wrong keyboard, menus that do not exist etc. It's also poorly translated. Thanks for suggesting it, though, as it allowed me an opportunity to find that PDF text search in pdfviewer is useless. In AdobeViewer, it merely hangs when I ask it to continue searching, but did find words. I really did not expect that. The manual mentions the slot exists, that it takes MicroSD up to 32Gb (some of us would spell that GiB to avoid confusion, as b is frequently used for bit and G is 10^9).. which of course means microSDHC, a different protocol. SD only goes up to 2GB, formally. My card happens to be SDHC although it is only 2GB, but supports both protocols. There's no mention of the speed class there, nor on the box - only in this forum. Another document I have been reading is what little of the SD specification that is public. Conveniently, this includes no way of confirming what the Class ratings even mean. The common hypothesis is that it means linear recording speed in MB/s, which in the specification is carefully outlined; that means writing entire eraseblocks, a behaviour a video camera can easily apply. A computer, not so much.. unless you pass low level knowledge of the card to it and accept abysmal performance (none of the major OSes do this). The only other difference with higher class cards appears to be an optional write rate informational command, that could be used to detect slow cards. If you use that, naturally you'd assume a slow card if the command fails, so if they do, and require faster cards (which they should not), there's no excuse to not show a warning. The fact of it is, the SD slot isn't working as advertised, and instead of escalating this issue to the maker of that part, PocketBook is filing it as "probably doesn't happen with another card". That the failure mode is unacceptable as well is also glossed over. I'm sorry if I misunderstood your post. I still can't quite figure out what its purpose was.