Here's more (cont'd from where last left off):

stx $2001

wait_vblank:
lda $2002
bpl wait_vblank

wait_novblank:
lda $2002
bmi wait_novblank

wait_vblank1:
lda $2002
bpl wait_vblank1

wait_novblank1:
lda $2002
bmi wait_novblank ;??? WTF ???

Can't really explain it. That's just how it is.