Probably a camcorder, a computer, or a special recording sound system. Usually recording on a computer has the most benefit because you can save it, burn it to a CD, send it, etc. But I would...
No it was not Blackie although Blackie was his main guitar. His 2nd guitar was Brownie a sunburst stratocaster. He recorded layla with Brownie. If you want to see a picture of it look on the back of...