[Oberon] FPGA - Save / Restore OBERON.FS

Hi, Reading some earlier post by Paul Read, I look for `dd' syntax to save and restore my work on uSD card. Providing uSD card is formatted as 256MB FAT + 65MB OBERON. Restore my work indexed as `1' may work like this, $ dd if=OBERON1.FS of=/dev/sdc bs=1024 seek=262145 By how about saving the work first, $ dd if=/dev/sdc of=OBERON1.FS bs=1024 skip=262145 count=??? What count should I use? `System.Watch' may give a clue, but does not seem exact. I could also use a fixed value of the whole 65MB Oberon partition, but not sure if below is correct $ dd if=/dev/sdc of=OBERON1.FS bs=1024 skip=262145 count=$((65*1024*1024)) Many thanks. Tomas