Differences between MNP, Modem, Modem-MNP, and Real Modems

One of the Newton 2.x OS Q&As
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This document was exported on 7/23/97.


Differences between MNP, Modem, Modem-MNP, and Real Modems (2/5/96)

Q: I want to just connect to a Newton device over a cable from a MacOS or Windows machine - what do I need to use to get reliable communications?
Q: I want to have the DILs answer an incoming call over a modem. How can I do that?
Q: What's the difference between the "Serial" and "Modem" Mac connection types?

A: In release 1.0 of the DILs, the best way to connect to a Newton device is by using a MNP connection over a serial cable. This is what you're using when you set connection type "Modem" on MacOS computers and "MNP" on Windows computers. This actually has nearly nothing to do with modems as such; it means you're connecting over a serial cable using MNP error correction and compression. (And on Windows, it's the only supported option at this time.)

Currently you cannot use a true modem with the DILs to connect to a Newton device.

In general, you will never use the "Serial" connection type on a MacOS computer; that connects over a serial cable (like "Modem" does) but offers no error detection. Therefore, you would have to write your own code to check that data arrived safely.