GP32 Question About Phodrive.

[Emanon]

Hi!

I've been googling around some, but can't seem to find the author's page or contact information, so I thought I might ask here.

Why is it that I have to press select before exiting PC-Link when I use Phodrive? (SlubFW with phodrive to be more precise).

I was thinking about making a firmware that basically lets phodrive run in the background, so there's no need to enter pclink before connecting the GP32 to a PC. However, in order for a filetransfer to be successfull, I have to press select.

I tried pulling the plug without select, and the changes to my SMC wasn't registered.

 

[Zap]

You need to push select because everything is not written during transfer, some is only cached and written when you exit..

 

[Squidge]

I didn't write Phodrive (that was Phoda), but I wrote gpDrive, which is what Phodrive is based on:

Basically, the data from the pc is placed directly into a cache, rather than being written directly to disk, and then when the cache becomes full, it is gradually emptied to make room for more data. This means that when the PC decides to update blocks already written, they will be present in the cache already, so don't need to be read from the smc or rewritten.

You can get around this problem by adding a timer to the code, so that blocks are written from the cache to disk after they have sat in the cache for a few seconds or so, or just use it as a read-only cache, but then performance will suffer, as blocks on the smc will be written more than once.

 

[Emanon]

Thanks for your help!