Have a casio px 320 and trying to use it in GarageBand on my Mac OS X. Connecting USB cable from USB output on Casio to USB input on Mac doesn't work. Any help?

Like your Yamaha midi needs drivers.
https://www.solvusoft.com/en/update/drivers/music-keyboard/casio/privia/px-120/model-numbers/

Unfortunately, the SP33 pedal will not work with the PX-830BP. Casio lists that the SP33 will only work with the PX-150BK, PX-150WE, PX-160BK, PX-160GD, PX-350BK, PX-350WE, PX- 360, and PX-560 keyboards.

The PX-830 manual does not list the stand or the pedal unit as separate items if you need to replace them. The pedal unit has 3 pedals like a traditional piano. I wish that I had better news for you.

Cindy Wells

Newer Casio models that have "class compliant" USB interfaces such as the PX-330 would work (plug and play) since they now have "class compliant" drivers.
Unfortunately PX-300 is an older model that would need specific drivers and Casio only made drivers for Windows PCs.

Casio don't supply PX330 drivers for IPAD.
Get a Windows 8.1 tablet or connect PX330 to a desktop PC and use IPAD to Remote control that PC.

PX 410r uses IDES 4.0 downloadable from
http://www.casio-europe.com/euro/emi/specials/ides/downloads/
and not another version.

I suggest you uninstall the Casio USB driver from Control Panel'system'device manager then Reboot the PC without the USB cable.
Download latest USB driver from :-
http://support.casio.com/en/support/download.php?cid=008&pid=20
64 or 32 bits versions are both available.
Load driver first. Plug in the usb cable only when software tells you to do so.
Uninstall Data manager if wrong version.
Install IDES 4.0

Make sure you follow the steps of the procedure below exactly. Connecting incorrectly can make data
send and receive impossible.
1.
Turn off the digital piano and then start up
your computer.
• Do not start up the music software on your computer
yet

3.
Turn on the digital piano.
• If this is the first time yo
u are connecting the digital
piano to your computer, the driver software required
to send and receive data will be installed on your
computer automatically.
4.
Start up your computer's music software.
5.
Configure the music software settings to
select one of the following as the MIDI device.
CASIO USB-MIDI

Only new models will work with MAC.
Older models work only on PCs. But there mmay be 3rd party drivers for the MAC. I found one for my WK8000 by searching using Google.

Check that the front of the keys is not hitting the lower plastic case front. If they hit it, then you need to disassemble the case partly and see what has shifted. It is ALSO possible that something has caaaused the aftertouch sensor to move out of position and it is hitting the keys early. ANY of these conditions needs to be addressed before damage is done.

Just did it today. Hooked up CTK-720 to Imac with Snow Leopard (10.2.6) using GarageBand.
Steps: 1) Go to : http://code.google.com/p/casiousbmididriver/ 2) Download the CasioUSBMIDIDriver.plugin (see the two choices on the right side of screen) 3) Place the CasioUSBMIDIDriver.Plugin file into the MIDI Driver subfolder: Macintosh HD => Library => Audio => MIDI Drivers 4) Restart 5) Plug in USB cable, open GarageBand, turn on Casio 6) In GraarageBand Open New Project, Start by using Piano, Select Keyboard (command K) in the Window menu 7) You should see the keyboard being played on the screen.
PS: Thank you Francois Ferland.

Try this driver.
https://code.google.com/p/casiousbmididriver/