AT - Attention: indicates to the modem that the following characters are a

command. Begins almost all commands. You must finish with a Return.



<3 plus signs> - Escape: interrupts a session by taking the modem out of

terminal mode and putting it into command mode, where you can issue more

commands or hang up. It does not require the AT prefix, but it must be

preceded and followed by at least one second of no data transmission. The

plus sign can be changed to another character (see Register 2 below).



A - Answer: tells modem to answer a call without waiting for a ring, allows

you to switch from voice to computer.



A<slash> - Again: repeats the previous command, generally used to redial

after getting a busy signal. Doesn't require AT before or Return after.



Cn - Transmitter Carrier: used when more than one modem is connected to the

same phone line. C1 (default) turns it ON fro normal operation iwth one

modem. C0 turns it OFF for setting a RECEIVE ONLY condition of an

additional device sharing the phone line.



D - Dial: indicates to the modem that the following characters are part of

a phone number. Spaces and hyphens are OK. Commands commonly used with D

include: P, T, R, comma and semicolon.



P - Pulse: selects pulse method for dialing. It's the default setting for

the modem.



T - Touchtone: selects touchtone method for dialing. All subsequent

commands will be executed in touchtone. The modem recognizes the # and *.

Dialing speed can be changed (see Register S11).



R - Reverse: allows you to contact "originate only" modems. Placing this

command at the end of a dialing sequence puts your modem in answer mode and

enables you to contact those modems programmed to transmit, but not to

receive calls.



<comma> - Pause: creates a two-second pause in transmission, most often

used in dialing sequences. The length of the pause can be changed (see

Register S8).



<semi-colon> - Return to command mode: returns you to command mode after

dialing. It must be the last character in the dialing sequence.



En - Echo: used only in command mode. When ON (E1, the default), the

characters you type appear on (echo to) the screen. When OFF (E0),

characters don't appear on the screen, but commands are executed anyway.



Fn - Duplex: controls the echo in terminal mode. F1 (default) indicates

full duplex communication, where the local echo is turned OFF and your

characters are echoed back to you from the on-line system. Use F0 to turn

the local echo ON if the system does not echo back characters. (If local

echo is ON and you are transmitting to a system that echoes back,

everything you type appears twice, lliikkee tthhiiss.



Hn - Hook: used to hang up (put ON the hook) or pick up (take OFF the hook)

the phone. When you terminate a call with 3 plus signs, the phone lines are

still open, although the link to the host computer has been broken. H0 (or

just H) hangs up. H1 takes the phone OFF the hook. Default is 0. Note that

you must first issue the Escape command (3 plus signs) becore you issue the

hook command.



In - Inquiry: requests the product code (I0) or the ROM checksum (I1).



Mn - Monitor speaker: enables you to listen in on an attempted connection

or a connection in progress. M1, the default, turns the speaker on during

command mode and off in terminal mode. M2 turns the speaker on all the

time. M0 turns the speaker off completely.



O - Online: returns you to terminal mode (online) from command mode if you

have been issuing commands in the middle of a telecommunication session.

You can use the Escapte code (3 plus signs) to get out of terminal mode

without terminating the session, issue commands, then type ATO to resume

telecommunicating.



S - Set registers: sets the 14 registers that control various elements of

communicating. Registers and their function are listed below.



Sr? - Query register: tells you the current value of register "r".



Xn - Result codes: status reports that are displayed on the screen in

numeric or verbal form (see the V command). YOu can prevent the codes from

being displayed (see the Q command). There are 10 codes divided into three

overlapping groups. X0 selects codes 0 thru 4, X1 selects 0 thru 5, and X2

selects the full set of codes. The following table lists and describes the

codes.



   0  OK            Command being executed

   1  CONNECT       Going online

   2  RING          Incoming call (enters answer mode)

   3  NO CARRIER    You're disconnected

   4  ERROR         Invalid command

   5  CONNECT 1200  Online at 1200 baud

   6  NO DIAL TONE  Returns to command mode

   7  BUSY          The host is busy

  11  RINGING       The host is not busy

  12  VOICE         A person, not a modem, answered



Qn - Quiet: decides whether or not to display result codes. Q0, the

default, displays the codes and Q1 suppresses them.



Vn - Verbal: determines whether result codes are displayed as words (V1,

the default) or code numbers (V0).



Z - Zap: resets modem to all default settings. Has the same effect as

unpluggin, then plugging it in again. Can be used to initiate new DIP

switch settings.



Setting Registers

=================



There are 14 registers, most of which deal with timing, that alter aspects

of the modem's memory to tailor the performance to your needs. All the

commands use the same structure:



ATSr=n  where r is the register number and n is the new value



Reg   Default     Function

===   =======     ==========

S0    DIP 1       Sets number of rings before auto-answering

S1    0           Counts and stores number of rings coming in

S2    43          Redefines the ASCII code for the Escape code character

S3    13          Redefines ASCII code for Carriage Return

S4    10          Redefines ASCII code for Line Feed

S5    8           Redefines ASCII code for Backspace

S6    2           Sets number of seconds to wait for a dial tone.

                  The lowest possible value is 2.

S7    30          Sets number of seconds to wait for carrier

S8    2           Sets duration in seconds for the pause (comma) and the

                  pause between command re-execution for Repeat command.

S10   7           Sets duration in tenths of seconds to wait after loss

                  off carrier before hanging up.

S11   70          Sets duration and spacing, in milliseconds, of

                  touchtones. 50 is the minimum value.

S12   50          Defines guard time in 50ths of second for Escape code

                  sequence.

S16   0           Modem self-test:

                  0=Data mode (no testing)   1=Analog loopback



DIP Switches

============



1     Auto-answer suppressed           DOWN

      Modem answers on 2nd ring        UP

      

2     Carrier detect on pin H-K        DOWN

      No carrier detect signal         UP

      (must be up for Plus/4!)

      

3     Indicate to computer speed of incoming call  DOWN

      Disable speed indicate                       UP



4     DTR (Data Terminal Ready) always on          DOWN

      DTR normal; computer controls DTR            UP



NOTE: When you change a DIP switch setting, the new setting is initiated 

when you plug in the modem. If the modem is already plugged in, initiate 

the new setting by issuing the Zap command (ATZ).



Disabling Auto-Answer on 3-DIP model

====================================



The following text and program for disabling auto-answer on the (older) 

3 DIP switch model of the 1670 is from John Iannetta 73510,2152.



The following BASIC program, when RUN, will create an

89 byte disk file.  Anytime that the file is LOADed "FILENAME",8,1 it will

disable the auto-answer mode.  The file is not to be RUN.  In fact, it may

be used with an existing BASIC program in memory. The BASIC program will

not be corrupted by doing so.  Testing was on a C-64.



10 input"filename";f$

20 open8,8,1,f$

30 fori=1to89:ready

40 print#8,chr$(y);:next

50 close8

100 data173,2,6,65,84,83,48,61,48,13

110 data24,165,34,105,2,133,45,165,35

120 data105,0,133,46,169,1,162,173,160

130 data2,32,189,255,152,170,32,186

140 data255,32,192,255,162,2,32,198

150 data255,162,2,32,201,255,162,249

160 data189,181,1,32,210,255,232,208

170 data247,32,228,255,32,22,231,201

180 data75,208,246,169,2,32,195

190 data255,32,83,228,32,204,255,76

200 data116,164,139,227,181,2



             The program LOADs at $02AD, ending at $0303, where it

overwrites the ready mode and input buffer vectors. The latter is changed

to $02B5, the start of the routine.  After the LOAD, the BASIC goes to the

new vector, where the correct START OF VARIABLES address is put into $2D,

$2E (it had been changed by the LOAD).  Then a 300 baud RS-232 channel is

OPENed, "ATS0=0 <CR>" is sent through it, and the routine waits for the "K"

of "OK" to be received from the modem and printed.  Next, the file is

closed, the original vectors are installed, CLRCHN is called, and the JMP

is made to ready mode.



[This program (tokenized BASIC) is in LIB 12 under the name NOANSR.BIN]

