What caterpillar?

Out weeding today - damn maple tree - and I found this guy hanging out. I went through 12 pages at bugguide.net and haven't been able to find it! Not sure if it a 'good' bug or a 'bad' bug. I am thinking black swallowtail but sent an email to my regional field coordinator for butterflies to check. Usually they don't have the red dots which is why I question its kind.

Staked the tomatoes today and the Sungolds are starting to flower. My handy book Trowel and Error says it is now time to water with epsom salt. 1 tablespoon to 1 gallon of water. The raspberries are now in full harvest mode. I am thinking I have gotten at least 2 pints in the paste 3 days! I love fresh raspberries.
So, I planted Garden Purslane a l-o-n-g time ago in some window boxes and was caring for what I though was purslane very diligently. Apparently they were weeds! The purslane has succulent leaves and they finally emerged from the soil. Light dawns and out went the weeds and in more purslane seeds. Now I think I got it down pat!