Spaced Out ::

SD cards are all the same right? You stick them in your camera, PDA, laptop etc and they just work? Well have a look at the above article and you’ll quickly realise that this isn’t the case. SD, SDHC, mini-SD… the list goes on. And its caught me out. I had a well loved Palm Zire 72 which, yes, has an SD card slot. And it supports SD, but not SDHC cards.

And what is SDHC? Well SD cards had a physical limit of 2Gb based upon the transport method used to access them. As capacities grew this became a problem and so SDHC was developed to overcome this. Exactly the same physical specifications, just a different transport method used, although with a disk format that could address above 2Gb. FAT16 had been the format of choice and was replaced by FAT32. OK, so new cameras could access these large capacities (at 16Gb now), but older devices couldn’t. If the device had an OS or firmware, then a new driver would be needed to recognise SDHC. And of course work with FAT32.

Fast-forward to a couple of weeks ago when I became the proud owner of a Palm TX and, yes, you’ve guessed, it doesn’t support SDHC. Its a great device, but having shipped originally in 2005, no SDHC support was needed. Unfortunately Palm have a history of NOT updating the OS of existing devices; you have to buy a new one. Except of course the TX is the most up-to-date Palm PDA. Added to this the sale of the OS to Access software and the extreme delay on their own Linux based replacement and we have this current problem, which means 2Gb cards are the maximum supported. Even more galling with their smartphones, using the same OS, do now support SDHC. One minor useful hack is at Palm PowerUps where a FAT32 driver has been back-ported to the TX. SD cards (not SDHC) are available upto 4Gb which means you can format it in FAT32 and access the entire volume in one go. Neat!