Bad Sectors

[Dryer Lint]

I just formatted my 128MB SMC (using Slubman's firmware) and found out I have one bad sector on it.

But how many sectors are there in total? How large is the loss of disk-space per sector?

Thanks.

 

[Jaw]

i have 8 cards, and they all have at least 1 bad sector, would like to know what loss this creates as well

 

[Robster]

Not actually a simple question! SMC has "sectors" (pages) of 512 bytes, but these are arranged as "clusters" (blocks) of 32 pages which makes 16k. If you have a bad page it will take out the whole block so you'll lose 16k.

However, the SMC makers knew that there would be some bad blocks, and so they said that the maximum storage on a 128MB card (which would normally be 8192 blocks) shall actually be 8000 blocks. If some blocks are bad (and it's very common to have a few bad blocks) then it won't necessarily decrease your available storage at all.

It depends on the formatting program whether it treats a bad block as a bad cluster in the file system (in which case your available storage will drop by 16k), or it hides the bad block in the SMC block mapping system, in which case your available storage won't change.

I don't know what Slubman's firmware does with bad blocks though, which makes this post a little... pointless I guess

 

[Dryer Lint]

I don't know what Slubman's firmware does with bad blocks though, which makes this post a little... pointless I guess

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Not at all! This is exactly the kind of information I was looking for, thanks a lot!

Now I only need to know if Slubman formats the right way. Although even the whole 16k wouldn't be much of a loss. ;-)