How to Replace dial up modem with dial up modem?

Dial-up modems either plugged into a personal computer slot or were self-contained devices that plugged into the computer's serial port

No. Some operating systems will say that DSL connection attempts are "dialing," but it's not dial-up.

The speed is only as fast as the slowest link in the chain, so the answer is NO. The more the internet connection is diluted and split, the slower it will be.

If you have a dial up program (I.E Netzero) try turning the graphics quality down.

Telephone lines were designed for analog communication in the audible range (aka talking). To transfer data over a telephone line, the computer had to convert a digital signal into an analog one in...