it's a 306 - it takes SPECIAL NEEDLES... do NOT use regular machine needles, they are too long and will damage the bobbin case.
good news, you can get needles at:
http://www.allbrands.com/products/abp15426.html
one order will last you the rest of your natural life...
I have a 306 and a 319 = mechanical stitches - no motherboard to go blooey..
I've been using the 319 for piecing... I love them both