SD cards are 4-bit
Originally Posted by Wholesaler
it works in my pc could it be that my pocket pc only uses 4 bit sd cards? how can i check wht bit myne is
and so is your PDA. It's only very old PPC's (namely, the iPAQ 38xx series) that only had a 1-bit-wide interface.
"There are three transfer modes supported by SD: SPI mode (separate serial in and serial out), 1 bit SD mode (separate command and data channels and a proprietary transfer format), and 4 bit SD mode (uses extra pins plus some reassigned pins) to support 4 bit wide parallel transfers.
Low speed cards support 0 to 400 kbit/s data rate and SPI and 1 bit SD transfer modes. High speed cards support 0 to 100 Mbit/s data rate in 4 bit mode and 0-25 megabit per second in SPI and 1 bit SD modes."
As to the problem, do try to re-format the card in a card reader to either FAT (meaning FAT16) or FAT32. You can also read this thread
on FAT12 vs 16 vs 32 and various flash card formatting options and apps.