km@mathcs.emory.edu (Ken Mandelberg) (09/02/89)
My ultimate goal is to get a very compact 2400 baud modem for a Toshiba
T1000 laptop. These things tend to be very overpriced due to volume.
And I'm looking for an inexpensive solution.
My first try was a 2400 baud internal made by "megahertz" with a
discount price of $185. This was a real disappointment. The modem
works consistantly fine against some remote modems and consistantly
terribly against others. For example it was fine against a Trailblazer
but had nearly continuous noise against a Case on the same rotary. I'm
returning the megahertz.
Since it looks like I'm going to end up paying $200 or more for this,
I'd like to at least get an MNP modem for the money. I either want an
internal T1000 modem, or one of the tiny portable externals.
The only tiny externals at 2400 baud that I know of are the Worldport
and GVC. Worldport does not have MNP and discounts at about $250. The
GVC I've seen advertised is $160 without MNP, which is probably what
I'll try if there isn't a better suggestion. Does anyone know anything
about the GVC (like their address)?
Any suggestions or info would be appreciated.
--
Ken Mandelberg | km@mathcs.emory.edu PREFERRED
Emory University | {decvax,gatech}!emory!km UUCP
Dept of Math and CS | km@emory.bitnet NON-DOMAIN BITNET
Atlanta, GA 30322 | Phone: (404) 727-7963wtm@neoucom.UUCP (Bill Mayhew) (09/06/89)
One way to achieve MNP connectivity on a laptop computer is to use a host (i.e. the laptop) based MNP protocol realization. I use a Tandy 1400 with a Tandy, A.K.A. Ventel, 1200 bps modem. The Tandy modem does have an adaptive eqaulizer that allows it to handle many poor quality lines, but there are occasions where there are noise impairments other than impedance-mismatch echoes. In such cases I switch from using the Procomm terminal emulator program over to Mirror III with the MNP add-in module. The Mirror module supports MNP level 3. The host-based MNP seems slower than the AT&T 2224CEO modem that I use that has built-in MNP. There seems to be about a two second pause as the MNP packets are assembled with the software, while the modem based MNP seems to require about half that amount of time. The software lag is not CPU bound, as I tried running on an IBM model 80 with an IBM modem and saw similar delays. None the less, if you need error correction and have to live with a certian modem, the MIrror III MNP add-in (~$40US for the add-in plus whatever Mirror III costs these days) is a reasonably inexpesive and reliable solution. Any generic 1200 or 2400 bps modem seems to be acceptible for use with the software. Bill