[net.dcom] 1200 baud modems

dmmartindale (08/21/82)

I'd like to correct a few errors in slinac!derek's article about 1200/300
baud modems.  The 3451 can be set up to tell you what speed it answered
at via one of the RS232 control lines, but you don't need to use this.
The usual trick of having getty cycle between 1200 and 300 if it gets something
it doesn't understand is sufficient, and presumably what you have to
do with any of the other modems anyway.  Thus the 3451 has an asset of
dubious usefulness, but it certainly isn't a liability.
The Anderson-Jacobson 1259 is virtually a clone of the garden-variety 3451;
it doesn't have dialing capability of any sort yet but AJ claims they're
working on it.  The 1259 has circuit boards which are virtually identical
to the 3451 except that the Vadic has more expensive components in some
places (gold-plated IC sockets for example), and is functionally identical
except that you can't tell it not to answer the phone without dropping DTR
(which doesn't matter for computer-controlled use).  It certainly handles
3400 protocol as well as 212 and 103/113, and is somewhat cheaper than the
equivalent Vadic.  I'm typing this in via a 1259.

laura (08/24/82)

	How important is tone dialing?? Depends what you want to talk to.
there are various networks around that only support tone dialing, so if
you are buying a modem and planning to go work somewhere else (like various
bell places) in a few years, you may need tone dialing.

	I have a switch in my AJ 1259 modem which works (amazingly) like the
RV switch to drop DTR when i want to hang up the phone...thus giving me back
my phoone line without unplugging the modem from the phone jack.  Since the
AJ modem really is a clone of the RV modem, any AJ dealer should be able to do
the same for you -- the ones in Toronto (Unionville) will for $12 (Canadian).
AJ modems are also cheaper than the RV ones.  

							Laura Creighton
							decvax!utzoo!laura