Check Engine Light blinking for 1 minute

Question for the experts... Driving home from work last night my check engine light came on. This was different than other times when it has come in that it blinks 60 times (about a minute... i tried to count out the corner of my eye while driving). After it stops blinking, it goes to staying on constantly. I noticed during this time the A/C started to blow warm air... so shut off the A/C to try and eliminate items.

It did it a few more times on the way home, and it seams to follow a moderate acceleration where it doesn't downshift (the kind of accelleration when it may or may not need to downshift). Hard accelleration, or light acceleration won't trigger it to come one. I could feel it hessitating ever so slightly right before the light started to blink.

I'm planning to go to Auto zone tonight to get it read, but thought i'd pose the question here to get prepared for what maybe coming.

1997 4.6L LX 186,000 miles, stock everything