Unfortunately, you pointed me to great information but I am on MAC.
I have found that, it it use with Arduino.
**broken link removed**
The problem is, I need to control for now, at least at least 9 (or it can be 6). Also, in that schematic, there is no diode protection, is it ok?
I don't absolutely need to control them by computer (for now). I'd like to use the easiest solution.
I do not use my mac for this stuff so not sure what is possible (for sure I know my macbookpro have no parallel port) but what I can see from here is something like this:
1. if you want automation
- you need uC to control the magnet driver
- you can either use uC with USB support and talk to your mac or forget about control from computer all together and preprogram behaviour in uC / add some input buttons to "store/replay" patterns, program some "beats" that you can change by pressing a button on the uC
2. you do not want automation
- connect those xyz magnets via xyz switches and "play" the tune on the switches (not too interesting imho)
You can use arduino as your "uC platform" or you can build one yourself, check out some nice tutorials on "microcontrolers" faq. Again, not sure how all that work with mac, I dedicated one windoze box for electronic work as all my linux and osX boxes cannot help with the basic tasks when electronic work is at hand
The virtualBox helps as it can "pass trough" the USB port so you can get some things done, but again, you need to run windoze in the virtualbox space ...
As for the driver used on the schematic, L293D has built in diodes, donno about L293E that they use in the example, but you should need them if you want to protect the equipment (and also if you want to properly switch polarity). Check the datasheet for L293, you will find nice examples there.