[comp.dcom.modems] One chip 300 baud modem?

boortz@sics.se (Kent Boortz) (05/29/90)

Is there a cheap, low power, easy to use 300 baud modem
chip to use for a home made modem? Yes, I would prefer 1200 or 
2400 baud but I suppose they cost a lot more and need more
work to get running (or?) I already have a 2400 baud modem (not home made) 
but my goal this time is to build a REAL small and REAL cheap one.
I don't care to talk to the modem, just to call up and connect 
(no AT command set). Are there solutions without a line transformer?

Any suggestions?

Kent Boortz
boortz@sics.se

don@gp.govt.nz (Don Stokes) (05/29/90)

In article <1990May28.213649.18508@sics.se>, boortz@sics.se (Kent Boortz) writes:
> Is there a cheap, low power, easy to use 300 baud modem
> chip to use for a home made modem? 

Yes.  There is a chip called the AM7910 (or 7911), produced by AMD. This
is almost a complete modem on a chip; just add power, line drivers and
go.  The chip supports FSK modes: V21 (300bps) V23 (600/1200bps hdx,
1200/75 fdx) and a Bell mode or two.  Not sure what the power through
this thing is like -- it's been around for a while.  Commonly referred to
as the "world chip", at least before V22/V22bis became popular. 


Don Stokes, ZL2TNM    /  /                              PSI%(5301)47000028::DON
Systems Programmer   /GP/ Government Printing Office      Postmaster@gp.govt.nz
____________________/  /__Wellington__New_Zealand________________don@gp.govt.nz
         For every action there is an equal and opposite malfunction.