The cow was my gateway clue to see what was going on. I was hoping to find a few more themers in the grid, but there were a couple in the clues too. Happy memories of watching this in the packed first year Uni hall common room !
Took me ages to get how 9a parsed - that, with 1a and 2d, was my last stretch.
Never used 10a or seen it but I can imagine it being used in phone software developers' techie discussions.
11a leaped out at me, too - but I thought it was too easy and tried to make something else looking for anagrams in the clue. Didn't go well.
Thanks Brendan and all.