DMA channels and a question about AT commands

Hi folks.

I've been mulling through some notes in prep to possibly take the A+ Core next week. Have a few fuzzies I'd like to see if I can get cleared up:

1. I saw a question somewhere about what the default assignments are for the DMA channels. It's not listed in my study guide; is that something about which I need to be concerned for the exam or does the new 2003 revision lend itself away from DMA and more towards newer features? If DMA is indeed important, where might I get such a table of assignments?

2. In dealing with modem AT commands, I've seen both ATX and ATZ refer to themselves as "reset" commands. How would I be able to differentiate between them? My current understanding of them is that ATZ is a total reset and perhaps I have inferred that ATX is a "default restore" type of deal.


Your help is appreciated.

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