12-7-93               Zoom/Modems- specs/settings

                         Don Hinds - Tech Support

     There  are  too many models, present and past of Zoom modems  to  list
each  individually. They fall into two basic groups. V-series with  V42bis,
(both  2400  and  V32(bis) models), and plain  2400  modems.  All  V-series
Zoom  Faxmodems use both Class 1 & Class 2 FAX. Non-V-series modems may  be
either.  Zoom/modems support (depending on model) the following  standards:
CCITT - V32(bis), V42(bis), V22(bis), V21, & Bell - 103, 212A.

     The  plain  2400 modems are Hayes Smartmodem compatible.  The  factory
defaults  are  like  Hayes, including &C0 &D0. All  Hayes  Smartmodem  2400
settings and AT commands should work. Our recommended INIT string for  most
PC applications is AT&F&C1&D2, Mac AT&F&C1&D0. Use XON/XOFF flow.

     The V-series modems include 2400v42bis data/faxmodem/voice modems, and
v32(bis)  9600+ modems. Factory defaults are the same as the  2400  modems,
plus  v42bis protocol negotiation = ON, RTS/CTS = ON. The recommended  INIT
string  is  the same as the 2400 plain modems. Two exceptions:  The  'large
white'  v42bis  modem  and the v32 Turbo modem, add  S36=7  to  the  string
(default  in  all  other V-series Zoom modems). We recommend  &Q6  to  turn
v42bis protocol OFF, and &Q5 to turn it ON. In some cases (direct mode) &Q0
may  replace  &Q6. RTS/CTS flow &K3 = ON, &K4 = XON/XOFF, &K0 =  none.  Set
software   Autobaud =OFF, follow connect =OFF. Set v32 modems to 19,200  or
38,400, and 2400 v42bis modems to 9600 in the software.

     I  would  say for almost all applications you can  devide  Zoom/modems
into  two groups. Plain 2400 Zoom, and Zoom V-series modems.  Just  include
the S36=7 for the V-series, (AT&F&C1&D2S36=7) and it will set the only  two
that  are  not that way by default, and don't affect the others,  which  do
have that default.

     For  PCs  you  use  a  straight  through  cable.  MACs  should  use  a
'Universal' cable. Some 'odd' system may require a null-cable.

                                   Don Hinds - Zoom Tech
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