View Full Version : A bit of info for any Crystal Focus owners using a Mac

11-19-2007, 07:28 PM
Here is a bit of good info for anyone who is buying Erv's CF card and is using a Macintosh computer....

Because of the way the card is programmed...and the ability to change the soundfonts, one must FORMAT the SD card before loading up any new soundfont. Basically you re-write the ENTIRE card when you change a soundfont. This is just a function of how CF works.

Even though a Mac allows you to format the card in FAT 16 (the required format for CF to recognize the card), if you attempt to format the card in OSX, you will get errors once you reload the soundsets and boot your saber. On my saber, I was getting sound dropouts....menu items would not play properly. I was freakin.

To solve this, I rebooted my Mac into Windows XP, and reformatted the card, loaded up the same soundsets...and everything worked as expected.

I tried this multiple times, so I do not believe this is a fluke or bad format.

So the bottom line is: Erv's CF likes Windows to do the formatting for the SD card.

Caveat: Since editing the config file does not require a re-format of the card....those types of edits are just fine in OSX. No problems overwriting the config file.....only when you reformat the SD card to load new sounds.

Hope this helps anyone who might have a Mac and is buying Buttered Toast......make sure you have a partition with XP installed....or a PC in the house.


11-20-2007, 01:53 AM
Great post, Kamurah... I know a few people who are solely Mac folks that will need CF help.

Something I should mention... which might give people more ideas if they are having problems... ok... here we go.

Erv's CF card needs to DIRECTLY access every single bit of info from the SD card for many reasons... but just know that it's the best way to handle things in order to keep costs down and reduce latency as the processor goes "looking" for info, finds it... and brings it "back" to be played or whatever...

...as long as the information stays (and I'm simplifying things quite a bit) "in a linear fashion", all contiguous blocks... you're good.

^ = start of file
* = file information
. = empty bit/byte whatever you like... empty spot!


Something like that is great. Usually works the first time you copy things over. HOWEVER... when you start CHANGING things... Windows has an "interesting" habit of deleting ONLY a file header... and then OVER-WRITING old information with new info...

* = old file information
& = new file information


This can (and will) COMPLETELY jack up CF's ability to read things, since suddenly, there are "empty" spots, and in some cases (due to even MORE complex file structures)... Windows will "split" a file into multiple parts if the NEW file doesn't fit where the OLD one was!!!

* = old file information
& = new file information
% = new file information "continued", lol


This is indeed a SIMPLISTIC way to show what the heck is going on... but as you can see... imagine files stored in 28 pieces... blank spaces... pointers... headers...

It will freak CF out. CF prefers CONTIGUOUS blocks. NO "extra" space in between. NO "sound headers" (thus the unsigned, little endian, .raw format, etc.). Just a pretty little linear row of data with no blips, no burps, no hits, no runs, no errors... :)

So... formatting CF ***EVERY*** time you change information... is essential. Using FAT16 (not Fat32) is essential.

Mac users may indeed STILL be able to get the files on there with no issues... but they will likely need to avoid the Mac OS as well--which (much in the way Windows does) controls and regulates file allocation... creating blocks, pointers, gaps, segments, fragments, blah blah blah.

*WHEW*. Let's hope it helps the newbies...

11-20-2007, 02:13 AM
thanks all for this usefull info and tutorial. True, I've been a bad studient, I haven't tried to gain access to a macintosh to test.
What I know is that the formatting is ok, but it seems that the FAT is slightly customized by MacOSX, and you have some special file descriptors in there. I'm going to look for a freeware utility that allows real and compliant windows FAT on mac. I'm pretty sure it exist.
Now, with the mac intel, it should be easier to get a windows partition to do that, however, I would love to see thing working better on a mac.
Promise, I'll do my best to experience mac formatting and look why it does not work.

About formatting / reformatting for sound upgrade : it's been all said and very well explained by novastar. More than complexity of code (I could cope with that) it's just a matter of speed access to the SD, and it's not possible to stream real time audio from the SD if it's fragmented. So... but how come ? I can do that with my USB card reader, I play MP3 in winamp from my 2 GB SD card ??? yes, indeed. But the whole song is buffered in RAM in the PC. Even SD card reader car audio player do that. I have like 1.5 KB of RAM in the microcontroller only (KB, about 1500 bytes) so I can do buffering.

11-20-2007, 05:39 PM
Now, with the mac intel, it should be easier to get a windows partition to do that, however, I would love to see thing working better on a mac.

Promise, I'll do my best to experience mac formatting and look why it does not work.

I know a couple of folks at Apple who might have some ideas; I'll ask.

Just to make sure that I understand correctly: what matters most is that individual files' blocks be sequential and contiguous, yes?

Are there other restrictions as well? (For instance, if the Mac adds some additional directory entries for bookkeeping purposes, are they likely to confuse the Crystal Focus?)

11-20-2007, 08:46 PM
Pretty much, yeah.

For the most ideal conditions--CF wants the data raw, unchanged, contiguous, and un-appended.

Sure, there are "slight exceptions" if that even makes sense, but as far as I've been able to tell--sometimes even altering the config.txt file can cause problems. Normally, most have said this is a non-issue... BUT... I think it is because the file GENERALLY stays the same overall SIZE... but values change.

HOWEVER... if the config.txt file changes in size (smaller or larger)... you may get the same issue as when dealing with an altered sound file, or entire sound font.

11-20-2007, 10:31 PM
the first thing is that I'm not even sure that MAC is formatting in FAT16. Might say FAT but it's FAT32.
The second point is about special files and hidden files. It shouln't be a problem except if they are to numerous in a folder.

Then, yes, the sequecial and contiguous block writing is essential. I have to check on vista too, I've been notified of some problems too.

11-21-2007, 04:42 AM

On my machine, it says specifically the volume is formatted FAT16.

....but then my machine tells me I am handsome and powerful...so I don't know if I trust it. :D