ZyXEL Communications Services GmbH.
                                                     edited by Manfred Recla
                                                                May 16, 2000



        Release Notes on ZyXEL's "G1" Modem series (=> U-1496xx)
        Version 6.22     - PUBLIC RELEASE -       March 27, 2000
        ========================================================


1.) filenames:
--------------------------------------------------------------------------
R622.TXT ........... This release note for U-1496 series firmware v6.22
ALLNOTES.ZIP ....... all release notes of previous firmware releases !


internal modem card (for PC's long ISA 8-bit slot), max. 19200bps
RM622BP.U24 ......... U1496B+          -> firmware v6.22 for EPROM U.24
RM622BP.U25 ......... U1496B+          -> firmware v6.22 for EPROM U.25


internal modem card (for PC's long ISA 8-bit slot), max. 16800bps
RM622B.U24 .......... U1496B           -> firmware v6.22 for EPROM U.24
RM622B.U25 .......... U1496B           -> firmware v6.22 for EPROM U.25


external modem with LEDs, max. 16800bps
RM622E.U24 .......... U1496E           -> firmware v6.22 for EPROM U.24
RM622E.U25 .......... U1496E           -> firmware v6.22 for EPROM U.25


external modem with LEDs, max. 19200bps
RM622EP.U24 ......... U1496E+          -> firmware v6.22 for EPROM U.24
RM622EP.U25 ......... U1496E+          -> firmware v6.22 for EPROM U.25


modem card for 19" rack system, max. 16800bps
with support for ZyXEL's NMS (Network Management System)
RM622RN.U24 ......... U1496R and RN    -> firmware v6.22 for EPROM U.24
RM622RN.U25 ......... U1496R and RN    -> firmware v6.22 for EPROM U.25


modem card for 19" rack system, max. 19200bps
with support for ZyXEL's NMS (Network Management System)
RM622RNP.U24 ........ U1496R+ and RN+  -> firmware v6.22 for EPROM U.24
RM622RNP.U25 ........ U1496R+ and RN+  -> firmware v6.22 for EPROM U.25


external modem with LCD (without backlight), max.16800bps
RM622S.U24 .......... U1496S           -> firmware v6.22 for EPROM U.24
RM622S.U25 .......... U1496S           -> firmware v6.22 for EPROM U.25


external modem with LCD (with backlight), max. 16800bps, 
with support for ZyXEL's NMS (Network Management System) 
RM622SN.U24 ......... U1496SN          -> firmware v6.22 for EPROM U.24
RM622SN.U25 ......... U1496SN          -> firmware v6.22 for EPROM U.25


external modem with LCD (with backlight), max. 19200bps
RM622SP1.U24 ........ U1496S+          -> firmware v6.22 for EPROM U.24
RM622SP1.U25 ........ U1496S+          -> firmware v6.22 for EPROM U.25


external pocket-size modem, max. 16800bps
RM622CP.U24 ......... U1496P           -> firmware v6.22 for EPROM U.24
RM622CP.U25 ......... U1496P           -> firmware v6.22 for EPROM U.25
-------------------------------------------------------------------------


Solved modem bugs:
==================
1. Can't do the ALB (selftest) from rack controller at data state.
2. Set S57.6=1 for DTE data format mismatched problem with the DTE
   that can't support overspeed clock.


electronic greetings from Vienna, Austria
Manfred Recla
**********************************************************
 ZyXEL European File Distribution - Coordination Center
 eMail:  support@europe.zyxel.com
 FTP:    ftp://ftp.zyxel-tech.de
 WWW:    http://www.europe.zyxel.com
 NEWS:   news://news.europe.zyxel.com
**********************************************************

                                                  ZyXEL Communications Corp.
                                                     edited by Manfred Recla
                                                               July 25, 1999


        Release Note on ZyXEL's "G1" Modem series (=> U-1496xx)
        Version 6.21  - PUBLIC RELEASE -          July 13, 1999
        =======================================================


1.) filenames:
--------------------------------------------------------------------------
R621.TXT ........... This release notes for U-1496 series firmware v6.21


internal modem card (for PC's long ISA 8-bit slot), max. 19200bps
RM621BP.U24 ......... U1496B+          -> firmware v6.21 for EPROM U.24
RM621BP.U25 ......... U1496B+          -> firmware v6.21 for EPROM U.25


internal modem card (for PC's long ISA 8-bit slot), max. 16800bps
RM621B.U24 .......... U1496B           -> firmware v6.21 for EPROM U.24
RM621B.U25 .......... U1496B           -> firmware v6.21 for EPROM U.25


external modem with LEDs, max. 16800bps
RM621E.U24 .......... U1496E           -> firmware v6.21 for EPROM U.24
RM621E.U25 .......... U1496E           -> firmware v6.21 for EPROM U.25


external modem with LEDs, max. 19200bps
RM621EP.U24 ......... U1496E+          -> firmware v6.21 for EPROM U.24
RM621EP.U25 ......... U1496E+          -> firmware v6.21 for EPROM U.25


modem card for 19" rack system, max. 16800bps
with support for ZyXEL's NMS (Network Management System)
RM621RN.U24 ......... U1496R and RN    -> firmware v6.21 for EPROM U.24
RM621RN.U25 ......... U1496R and RN    -> firmware v6.21 for EPROM U.25


modem card for 19" rack system, max. 19200bps
RM621RNP.U24 ........ U1496R+ and RN+  -> firmware v6.21 for EPROM U.24
RM621RNP.U25 ........ U1496R+ and RN+  -> firmware v6.21 for EPROM U.25


external modem with LCD (without backlight), max.16800bps
RM621S.U24 .......... U1496S           -> firmware v6.21 for EPROM U.24
RM621S.U25 .......... U1496S           -> firmware v6.21 for EPROM U.25


external modem with LCD (with backlight), max. 16800bps, 
with support for ZyXEL's NMS (Network Management System) 
RM621SN.U24 ......... U1496SN          -> firmware v6.21 for EPROM U.24
RM621SN.U25 ......... U1496SN          -> firmware v6.21 for EPROM U.25


external modem with LCD (with backlight), max. 19200bps
RM621SP1.U24 ........ U1496S+          -> firmware v6.21 for EPROM U.24
RM621SP1.U25 ........ U1496S+          -> firmware v6.21 for EPROM U.25


external pocket-size modem, max. 16800bps
RM621CP.U24 ......... U1496P           -> firmware v6.21 for EPROM U.24
RM621CP.U25 ......... U1496P           -> firmware v6.21 for EPROM U.25
-------------------------------------------------------------------------


Solved modem bugs:
==================
1.Leased Line problem:
  In some cases, the link layer may hang.

2.German EG model:
  Can't use tone dialing if country code is other than 237 (Germany).



electronic greetings from Vienna, Austria
Manfred Recla
**********************************************************
 ZyXEL European File Distribution - Coordination Center
 eMail:  support@europe.zyxel.com
 FTP:    ftp://ftp.zyxel-tech.de
 WWW:    http://www.europe.zyxel.com
 NEWS:   news://news.europe.zyxel.com
**********************************************************
                                                  ZyXEL Communications Corp.
                                                     edited by Manfred Recla
                                                               July 05, 1999


        Release Note on ZyXEL's "G1" Modem series (=> U-1496xx)
        Version 6.20a  - BETATEST -               July 05, 1999
        =======================================================


1.) filenames:
--------------------------------------------------------------------------
R620a.TXT ........... These release notes for U-1496 series firmware v6.20a

RM620aBP.U24 ......... U-1496B+          -> firmware v6.20a for EPROM U.24
RM620aBP.U25 ......... U-1496B+          -> firmware v6.20a for EPROM U.25

RM620aB.U24 .......... U-1496B           -> firmware v6.20a for EPROM U.24
RM620aB.U25 .......... U-1496B           -> firmware v6.20a for EPROM U.25

RM620aE.U24 .......... U-1496E           -> firmware v6.20a for EPROM U.24
RM620aE.U25 .......... U-1496E           -> firmware v6.20a for EPROM U.25

RM620aEP.U24 ......... U.1496E+          -> firmware v6.20a for EPROM U.24
RM620aEP.U25 ......... U-1496E+          -> firmware v6.20a for EPROM U.25

RM620aRN.U24 ......... U-1496R and RN    -> firmware v6.20a for EPROM U.24
RM620aRN.U25 ......... U-1496R and RN    -> firmware v6.20a for EPROM U.25

RM620aRNP.U24 ........ U-1496R+ and RN+  -> firmware v6.20a for EPROM U.24
RM620aRNP.U25 ........ U-1496R+ and RN+  -> firmware v6.20a for EPROM U.25

RM620aS.U24 .......... U-1496S           -> firmware v6.20a for EPROM U.24
RM620aS.U25 .......... U-1496S           -> firmware v6.20a for EPROM U.25

RM620aSN.U24 ......... U-1496SN          -> firmware v6.20a for EPROM U.24
RM620aSN.U25 ......... U-1496SN          -> firmware v6.20a for EPROM U.25

RM620aSP1.U24 ........ U-1496S+          -> firmware v6.20a for EPROM U.24
RM620aSP1.U25 ........ U-1496S+          -> firmware v6.20a for EPROM U.25

RM620aCP.U24 ......... U-1496P           -> firmware v6.20a for EPROM U.24
RM620aCP.U25 ......... U-1496P           -> firmware v6.20a for EPROM U.25
-------------------------------------------------------------------------


Solved modem bugs:
==================
1.Leased Line problem:
  In some cases, the link layer may hang.

2.German EG model:
  Can't use tone dialing if country code is other than 237 (Germany).

 

                                                  ZyXEL Communications Corp.
                                                     edited by Manfred Recla
                                                              April 12, 1999


        Release Note on ZyXEL's "G1" Modem series (=> U-1496xx)
        Version 6.20                             April 12, 1999
        =======================================================


1.) filenames:
--------------------------------------------------------------------------
R620.TXT ............ These release notes for U-1496 series firmware v6.20

RM620BP.U24 ......... U-1496B+          -> firmware v6.20 for EPROM U.24
RM620BP.U25 ......... U-1496B+          -> firmware v6.20 for EPROM U.25

RM620B.U24 .......... U-1496B           -> firmware v6.20 for EPROM U.24
RM620B.U25 .......... U-1496B           -> firmware v6.20 for EPROM U.25

RM620E.U24 .......... U-1496E           -> firmware v6.20 for EPROM U.24
RM620E.U25 .......... U-1496E           -> firmware v6.20 for EPROM U.25

RM620EP.U24 ......... U.1496E+          -> firmware v6.20 for EPROM U.24
RM620EP.U25 ......... U-1496E+          -> firmware v6.20 for EPROM U.25

RM620RN.U24 ......... U-1496R and RN    -> firmware v6.20 for EPROM U.24
RM620RN.U25 ......... U-1496R and RN    -> firmware v6.20 for EPROM U.25

RM620RNP.U24 ........ U-1496R+ and RN+  -> firmware v6.20 for EPROM U.24
RM620RNP.U25 ........ U-1496R+ and RN+  -> firmware v6.20 for EPROM U.25

RM620S.U24 .......... U-1496S           -> firmware v6.20 for EPROM U.24
RM620S.U25 .......... U-1496S           -> firmware v6.20 for EPROM U.25

RM620SN.U24 ......... U-1496SN          -> firmware v6.20 for EPROM U.24
RM620SN.U25 ......... U-1496SN          -> firmware v6.20 for EPROM U.25

RM620SP1.U24 ........ U-1496S+          -> firmware v6.20 for EPROM U.24
RM620SP1.U25 ........ U-1496S+          -> firmware v6.20 for EPROM U.25
-------------------------------------------------------------------------


2.) fixed following modem bugs:
-------------------------------
 . Celluar mode:
   ATO1 after connection may cause modem hang up.
 . The retrain counter reported by ati2 is incorrect.
 . The second retrain will force modem to drop the connection speed.
 . V.27/V.29 can't connect again after hang up in LL mode.
 . set ats55.7=1 will let DSR follow the CD if &S1.
 . V.22bis mode:
   .The compatibity problem with Tainet modem in LL mode. (But bit 2 of s38
    must be set (ats38.2=1) when ZyXEL U-1496 is at originate mode.)
   .The modem will generate some garbages after connection in none error
    control mode.
 . Can't modify data format when the setting is leased line and sync (sd)
   mode.
 . Let ats35.1=1 be factory default for countries cc=222 (China) or 223
   (ChinaT)
 . Pseudo Carrier Dedect (ats12.7=1):
   set ats12.6=1 will disable Rx timer check when enabled Pseudo CD.
 . In 4-wire Leased-Line, the modem can't sense carrier drop while only
   two line is broken.

3.) fixed following fax bugs:
-----------------------------
   .Improve the compatibility with Fax machine.
   .The modem can't be quickly aborted after issue "ATD" command.
   .Fax Class 1:
    If "AT+FRH=3" time out, the modem can't accept any AT command.
   .The modem should respond "OK" instead of "No Carrier", after issue "ATH"
    command.
         Release Note on U1496 modem Test Version 6.19    Jan. 16, 1998
       =================================================


1. Fixed modem bugs:
  .Sync Loss
   This verion improves performace of sync mode.
  .at#rev=? will not response error.
  .at#cls=? will not response error. (can not be detected by WinFax 8.0)

2. Added new feature:
  .The function of ATI3 command have been recovered in this version.
  .For Mainland China DDN
   set s57.6=1 It will cause that the incoming data format(TxD) is
               10 bits and the outgoing data fromat(RxD) is 11 bits while
               the character format setting is N,8,1.
   set s58.0=1 It will cause modem to resync better under bigger 
               deviation range of oscillator clock.
--
                                                   ZyXEL Communications Corp.
                                                      edited by Manfred Recla
                                                                July 23, 1997


              Release Note of U1496 Series Version 6.18
           ==============================================


New feature:
------------
1. Add "Psudo DCD HDX" feature by setting s12.7=1
   Psudo DCD HDX ---> If continously more than 48 mark received, DCD off,
                      otherwise DCD stay on.

New implemented:
----------------
1. Add ati3 response for legacy PnP-ID (UNIMODEM) under Windows95
   and WindowsNT 4.0
   ---> note: new INF driver files for Windows95 Plug&Play are required !
              you can request these files from our Internet FTP site:
              ftp://ftp.zyxel.co.at/public/u-series/1496/software/Windows95/

Bug fix
-------
1. Busy detection in voice record mode is more sensitive.
2. Change Russian CND default value.
3. Improve Russian busy detection.
4. Improve performance of synchronous operation when single external clock
   been applied.
5. Fix "Modem rings, when pulse dialing from attached telephone set".
6. Fix "Endless false connect at V.21, Bell 103, V.23" by setting s58.4=1
7. Fix leased line Originate mode accidently changed to Answer mode when
   pressing D/V key twice during handshaking.
8. Repeated generate answer tone during leased line handshaking by default.
   To disable this by setting s57.1=1.
9. Report Class 1 fax capability by factory default (s57.4=1)
   (for Symantec/Delrina WinFax Pro, MS Personal Fax for WindowsNT4, etc...)

                                             ZyXEL Communications Corporation
                                                      edited by Manfred Recla
                                                               Sept. 26, 1996


     Release Notes of U-1496 series modem,  version 6.17 (09/12/96)
     ===============================================================


Fixed the bugs:
---------------
1. In dial backup mode,	leased line is broken and dial-up line is up.
   For some reason dial-up line	is broken too, then the	modem will not
   restore to leased line or either retry dial-up line.
2. Null	character append after some display messages.
3. Not display dialing message when in redialing.
4. Synchronous connection sometimes randomly disconnect.
5. Answer tone can not be detected when	the line go through some specific
   PABX	to outside line.
6. Pin 140,141 too sensitive, add debunce timer.
7. Fax can not work if s35.1=1.
8. When	the Class 2.0 modem is initialized (AT+FCLASS=2.0) for fax/data
   adaptive answer (AT+FAA=1). The incoming data call is not reported
   properly, the first response	should be +FDM.


		     Firmware 6.16 release note	     02/09/1996
		   ----------------------------------------------


1.  Improve VCON too sensitive problem
2.  Improve AT detection during random data input
3.  Enhance recovery protection for unknown failure reason.
    a. exception 2 : Bus error, new added
    b. exception 3 : Address error, protected but new modified
    c. exception 4 : illegal instruction, protetcted but new modified
    d. exception 5 : Zero Divide, new added
4.  Improve the reliability of remote configuration.
5.  Generate answer tone on leased line answer mode for compatiblity with
    some modem which needs detect answer tone to identify originate
    modem existence.
6.  Set S48.1=1 to enable multi-auto on leased line operation.
7.  Improve carrier loss detection of V.22bis on leased line.
8.  Fix problem of adjustable transmission power of dialup line.
9.  Remove "Carrier lost 1" disconnect reason
10. Fix	V.23 11	data bit problem.
11. Ring detection enhanced.



		     Firmware 6.15 release note	     04-19-1995
		   ------------------------------

1. Fix ATQ1 bug.
2. Fix CTS stay	low problem on very noisy line.
3. Retrain count will increment	after ATO1 command.
4. On S+ model,	LCD will reflect the speed change before the first retrain.
5. In dumb mode, modem will not	accept escape sequence anymore.
6. Incorrect indication	of HS LED light	was fixed.
7. compatibility problem with version older than 6.00 was fixed.
8. Modem now only auto-detect format change (even, odd,	none parity
   or 1, 2 stop	bits) on 10 bits character length. Other than 10 bits, modem
   have	to be config first then	change the terminal setup.
9. Setting bit 2 of S52	will enable cellular dial backup.




		     Firmware 6.14 release note	     01-20-1995
		   ------------------------------

1. Support class 1 fax commands. But only when S57.4=1,	AT+FCLASS=? will report
   class 1 capability. This is for software compatibility reason.
2. Support class 2.0 ECM function on transmitting direction.
3. Command enhance : AT+VBT=n,m
	 n : duration
	 m : interval
   Now,	user can change	the tone duration and interval when sending tone by
   AT+VTS command.
4. In voice mode, H/W flow control will	not send XON / XOFF.
5. If s55.4 is set, any	DTMF tone that is received from	the Tel	line, the
   modem will pause to playing data. Only when the DTE issues <DLE>r can
   the modem start to play again.
6. Fix the <DLE><DC2> problem in 3/4-bit ADPCM mode.
7. Force s50 (inactivity timer)	disabled on leased line	operation.
8. Fix the bug of false	SREJ connection	even when SREJ is disabled.
9. AT auto-baud	will only detect speed change and will not detcet character
   length change.




		     Firmware 6.13 release note	     07-18-1994
		   ------------------------------


New feature:

Voice


   1. Add a new	3-bit ADPCM voice compression scheme, use AT+VSM=30 to select
	this mode. In this new format, every 5 samples of compressed data is
	packed into 2 bytes, the extra bit is set to 1 for resync.

	byte 1 : ÚÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄ¿  byte 2 : ÚÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄ¿
		 ³1³A³A³A³B³B³B³C³	     ³C³C³D³D³D³E³E³E³
		 ÀÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÙ	     ÀÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÙ

	1 : resync bit.
	A A A :	first  sample
	B B B :	second sample
	C C C :	third  sample
	D D D :	forth  sample
	E E E :	fifth  sample
		
   2. Add a new	4-bit ADPCM voice compression scheme, use AT+VSM=4 to select
	this mode. Two samples of compressed data is packed into 1 byte.
	It is necessary	to increase the	DTE speed to 57600 bps to use this
	compression scheme.

		 ÚÄÂÄÂÄÂÄÂÄÂÄÂÄÂÄ¿
		 ³A³A³A³A³B³B³B³B³
		 ÀÄÁÄÁÄÁÄÁÄÁÄÁÄÁÄÙ

	A A A A	: first	 sample
	B B B B	: second sample

    3. Accept hardware flow control for	voice data flow, use the command
	"AT+FLO=2" to enable the hardware flow control.	(default value is
	"AT+FLO=1").


Improvement:

FAX

1. Improved 2-D	high resolution	graphic	quality	on E model.

2. Fax receiving speed is command configurable on class	2 and
   class 2.0 now.

Modem

1. High	DTE speed AT auto-baud detection problem on E model fixed

2. Ring	volume control (ATNn) bug fixed

3. V.23	answer tone detection bug fixed.

4. V.26bis performance improved

5. V42 block resent count will have a wrong count when remote modem is busy,
   this	bug is corrected.

6. Modem automatically disables	terminal aborting if async leased line is
   set.

7. Modem can now accept	V.25bis	async command in sync-data (&M1) mode.

8. Set bit 7 of	S52 to select space or mark as the first signal	of the
   V.23	handshaking sequence.

9. The bug of modem disconnecting the line after second	ATO1 command
   is fixcd.

10. ATA	will not cause "ERROR" response	now if modem is	already	off hooked on
    EG+	model.

11. Will detect	V22bis carrier longer to recognize it as a carrier presence
    to improve compatibility.

12. Hook flash time can	be adjusted by setting S56, unit value is 10 ms.

13. Hardware reset (press D/V button on	E, E+ or ENTER key on S+ while
    powering on) will only reset profile 0 and 1 but profile 2 and 3
    will not be	affected.




		     Firmware 6.12 release note	     05-24-1994
		   ------------------------------

New Feature:
ÍÍÍÍÍÍÍÍÍÍÍÍ

Modem

1. ZyCellular mode added

ZyXEL U-1496 Series modems are equipped	with a special cellular	communication 
mode which enables the modem to	provide	reliable high speed data transmissions 
over cellular phone links
	  
In addition to normal modem, fax and voice operation modes, the	following
cellular modes are offered in ZyXEL's U-1496 series modems:
	  
Mode	     Speed
	  
Multi-Auto:  ZyX modes V.32bis/V.32/V.22bis/G3 FAX/Cellular Modes
CELL 14400:  14400/12000/9600/7200/4800	(AT&N42)
CELL 12000:  12000/9600/7200/4800 (AT&N43)
CELL 9600:   9600/7200/4800 AT&N44)
CELL 7200:   7200/4800 (AT&N45)
CELL 4800:   4800 (AT&N46)
	  
CELL 14400 will	connect	with another modem using cellular mode at a speed
of up to 14400bps.  It will also connect with another V.32bis/V.32 modem.
The actual speed depends on the	line condition.	The modem will automatically
fall-back or fall-forward within its speed range. CELL 12000, CELL 9600,
CELL 7200 and CELL 4800	limit the maximum speed	to 12000bps, 9600bps, 7200bps
and 4800bps, respectively.
	  
In Multi-Auto mode a ZyXEL modem will automatically and	dynamically select
the best speed and mode	in which to operate. Selecting one of the above
cellular modes manually	will limit the maximum speed at	which the modem	will
operate.

The ZyCellular mode is recommended when	using cellular links for modem
connection. It can also	be used	on other poor line conditions such as a
line with frequent large impulse noises.  ZyCellular mode is more noise
resistant, impairment resistant, and error resistant.
	  
It is simple to	use the	ZyCellular modems. Everything is determined
automatically by the modem.  The user needs only to set	S-register S49
bit 7 to leave the modem on cellular mode. S49 bit 7 tells the modem
where it is installed.	If S49.7=0, the	modem is installed in an office
connected to a normal telephone	line.  If S49.7=1, it means the	modem is
a mobile unit connected	to a cellular phone.  When a ZyCellular	modem
calls or answers another modem,	it will	indicate its cellular capability
and whether it is using	a cellular phone.  If both sides have the ZyCellular
capability and at least	one side is using a cellular phone, the	connection
will automatically be a	cellular mode connection.  If one side is a
non-cellular modem the connection will automatically be	a standard mode.
	  
If manual transmit power setting is desired, set S43.2=1 to disable auto
transmit power adjustment and use S49 bit 0-3 to set transmit power at -9
to -24 dBm.
	  
If cellular mode connection is never desired, set S43.3=1 to disable the
cellular mode connection.  The default is enabled (S43.3=0).
	  
You are	also able to send and receive faxes on cellular	links by just
setting	S49.7=1	on the ZyCellular modem	that is	installed on the cellular
site.  Now your	modem can send and receive faxes from fax machines and other
fax modems.

2. Support 100 dial digits on one dial string.

3. Bit s48.3 is	used to	reverse	V.23 channel speed.

	     Originate speed (send/receive)  Answer speed (send/receive)
   s48.3=0		      75/1200			   1200/75
   s48.3=1		      1200/75			   75/1200

4. Add ATO1 command, this command can force modem to request a retrain.

5. Set s48.4=1 and &D1,	DTR ON will make the modem dial	the default number
   and DTR OFF will make the modem hangup and reset profile 0. When the	modem
   is idle -wait for command- it will not dial a number	when the DTR signal
   changes from	ON to OFF.

6. In EG+ model, no more blacklist but the modem delays	30 seconds between
   every call. Press D/V button	on EG+ or "MENU" key on	SG+ will skip the delay
   and dial immediately.

7. Set s25 to define DTR delay timing. s25 specifies the minimum time that
   DTR signal must be off to be	recognized. Each units represents 10 ms.
   At least 4 ms for s25=0.


FAX

1. Class 2.0 Fax command is available on this version.

2. Add new command for class 2 .
    2.1:+FMINSP= Minimum phase C speed parameter (0 to 5).
	0:2400bps	1:4800bps	2:7200bps
	3:9600bps	4:12000bps	5:14400bps
    2.2:+FCQ= Copy quality check capability parameter (0 to 2).
	0:No copy quality check	capability.
	1:Only check 1D	phase C	data.
	2:Check	both 1D	& 2D phase C data.
    2.3:+FK  orderly fax abort command.

3. Report Detailed HangUp code information for both Class 2 and	Class 2.0.

4. Support T.4 1D/2D decompression, error line report and correction.
   Correction method for 1D: if	the number of consecutive error	lines are
   less	than 4 lines the error line is substituted by the previous good	line,
   otherwise the bad line is deleted. For 2D the error line is simply deleted.


VOICE

1. AT+VDD, This	command	sets the duration of DTMF tone detection. The unit is
   5 msec, default value is 6 (30msec).	The modem reports DTMF event when it
   detects a continuous	tone for this period.

2. AT+VDH, This	command	sets the threshold of the DTMF tone detection. The
   default value is 16.	Decreasing the value makes the modem more sensitive.
   The range of	VDH is 0-31.

3. The 2 and 3-bit ADPCM format	is changed. It is necessary to add the leakage
   coefficient for every sample. Please	refer to the C code program VCNVT.C
   and 610TO612.C for detail information. It is	recommended to re-record your
   greeting message because the	new leakage will give better voice quality.

4. AT+VGT, This	command	sets the playing volume	of voice. The default value
   is 192, a higher value makes	the voice louder. The range of VGT is 0-255.


RACK MODEM & NMS

1. DTR Alarm & Busy-out	(Off-Hook) function for	RACK-MODEM
   (at Dail up line) only.
   S53:	Set the	duration (in seconds) between DTR goes out to busy-out (DTR-
	alarm).	Only available on dial-up line and DTR option is 108.2 (&D2),
	108.2+RST (&D3). If DTR	option is set to 108.1 (&D1) the timer (S53)
	will start to count while DTR off and ring is come, and	continue to
	wait DTR ON till S53 time out then go to busy out (DTR-alarm, Off-
	hook) state.
	No function at Lease-line or DTR is ignored.
   S54:	Set the	duration (in seconds) to terminate the busy out	(DTR-alarm)
	state when DTR is come ON. Only	available while	DTR option is 108.2
	(&D2), 108.2+RST (&D3).

2. Dial	tone detection command for NMS S/W.



Improvement:
ÍÍÍÍÍÍÍÍÍÍÍÍ

Modem

1. Endless retrain on S48.1=1 (data mode only) is fixed.

2. Performance on V.26bis dial-up line half-duplex mode	is improved.

3. In security call back mode, the DSR and DCD will turn on only after call
   back	has established.

4. In ATI2 response, ">100M" error message fixed.

5. Set s43.7=1 to fix DCE connection speed. Modem will disconnect if the line
   condition does not permit the highest speed set by AT&N command.

6. In EG+ model, Flash "!" function is modified	to be the same as in E+.

Voice

1. "AT+VLS=16" command used to get response of "OK", it	is corrected to	"VCON".

2. Sending the "ATH" command in	voice mode and off hook	state used to hang
   the modem, bug fixed.

3. Sending "AT&F" following the	command	"AT+FCLASS=8" used to gets "NO CARRIER"
   , it	is corrected to	"OK".

RACK MODEM & NMS

1. Dial-in application setting lost problem fixed.

2. Reset to profile X command is now accept when Modem is in ON-LINE state.

3. RACK	modem Remote configuration problem fixed (Can be configure by remote
   side	modem).



		     Firmware 6.12 release note	     04-26-1994
		   ------------------------------

New Feature:

Modem

1. ZyCellular mode added

ZyXEL U-1496 Series modems are equipped	with a special cellular	communication 
mode which enables the modem to	provide	reliable high speed data transmissions 
over cellular phone links
	  
In addition to normal modem, fax and voice operation modes, the	following
cellular modes are offered in ZyXEL's U-1496 series modems:
	  
Mode	     Speed
	  
Multi-Auto:  ZyX modes V.32bis/V.32/V.22bis/G3 FAX/Cellular Modes
CELL 14400:  14400/12000/9600/7200/4800	(AT&N42)
CELL 12000:  12000/9600/7200/4800 (AT&N43)
CELL 9600:   9600/7200/4800 AT&N44)
CELL 7200:   7200/4800 (AT&N45)
CELL 4800:   4800 (AT&N46)
	  
CELL 14400 will	connect	with another modem using cellular mode at a speed
of up to 14400bps.  It will also connect with another V.32bis/V.32 modem.
The actual speed depends on the	line condition.	The modem will automatically
fall-back or fall-forward within its speed range. CELL 12000, CELL 9600,
CELL 7200 and CELL 4800	limit the maximum speed	to 12000bps, 9600bps, 7200bps
and 4800bps, respectively.
	  
In Multi-Auto mode a ZyXEL modem will automatically and	dynamically select
the best speed and mode	in which to operate. Selecting one of the above
cellular modes manually	will limit the maximum speed at	which the modem	will
operate.

The ZyCellular mode is recommended when	using cellular links for modem
connection. It can also	be used	on other poor line conditions such as a
line with frequent large impulse noises.  ZyCellular mode is more noise
resistant, impairment resistant, and error resistant.
	  
It is simple to	use the	ZyCellular modems. Everything is determined
automatically by the modem.  The user needs only to set	S-register S49
bit 7 to leave the modem on cellular mode. S49 bit 7 tells the modem
where it is installed.	If S49.7=0, the	modem is installed in an office
connected to a normal telephone	line.  If S49.7=1, it means the	modem is
a mobile unit connected	to a cellular phone.  When a ZyCellular	modem
calls or answers another modem,	it will	indicate its cellular capability
and whether it is using	a cellular phone.  If both sides have the ZyCellular
capability and at least	one side is using a cellular phone, the	connection
will automatically be a	cellular mode connection.  If one side is a
non-cellular modem the connection will automatically be	a standard mode.
	  
If manual transmit power setting is desired, set S43.2=1 to disable auto
transmit power adjustment and use S49 bit 0-3 to set transmit power at -9
to -24 dBm.
	  
If cellular mode connection is never desired, set S43.3=1 to disable the
cellular mode connection.  The default is enabled (S43.3=0).
	  
You are	also able to send and receive faxes on cellular	links by just
setting	S49.7=1	on the ZyCellular modem	that is	installed on the cellular
site.  Now your	modem can send and receive faxes from fax machines and other
fax modems.

2. Support 100 dial digits on one dial string.

3. Bit s48.3 is	used to	reverse	V.23 channel speed.

	     Originate speed (send/receive)  Answer speed (send/receive)
   s48.3=0		      75/1200			   1200/75
   s48.3=1		      1200/75			   75/1200

4. Add ATO1 command, this command can force modem to request a retrain.

5. Set s48.4=1 and &D1,	DTR ON will make the modem dial	the default number
   and DTR OFF will make the modem hangup and reset profile 0. When the	modem
   is idle -wait for command- it will not dial a number	when the DTR signal
   changes from	ON to OFF.

6. In EG+ model, no more blacklist but the modem delays	30 seconds between
   every call. Press D/V button	on EG+ or "MENU" key on	SG+ will skip the delay
   and dial immediately.

7. Set s25 to define DTR delay timing. s25 specifies the minimum time that
   DTR signal must be off to be	recognized. Each units represents 10 ms.
   At least 4 ms for s25=0.


FAX

1. Class 2.0 Fax command is available on this version.

2. Add new command for class 2 .
    2.1:+FMINSP= Minimum phase C speed parameter (0 to 5).
	0:2400bps	1:4800bps	2:7200bps
	3:9600bps	4:12000bps	5:14400bps
    2.2:+FCQ= Copy quality check capability parameter (0 to 2).
	0:No copy quality check	capability.
	1:Only check 1D	phase C	data.
	2:Check	both 1D	& 2D phase C data.
    2.3:+FK  orderly fax abort command.

3. Report Detailed HangUp code information for both Class 2 and	Class 2.0.

4. Support T.4 1D/2D decompression, error line report and correction.
   Correction method for 1D: if	the number of consecutive error	lines are
   less	than 4 lines the error line is substituted by the previous good	line,
   otherwise the bad line is deleted. For 2D the error line is simply deleted.


VOICE

1. AT+VDD, This	command	sets the duration of DTMF tone detection. The unit is
   5 msec, default value is 6 (30msec).	The modem reports DTMF event when it
   detects a continuous	tone for this period.

2. AT+VDH, This	command	sets the threshold of the DTMF tone detection. The
   default value is 16.	Decreasing the value makes the modem more sensitive.
   The range of	VDH is 0-31.

3. The 2 and 3-bit ADPCM format	is changed. It is necessary to add the leakage
   coefficient for every sample. Please	refer to the C code program VCNVT.C
   and 610TO612.C for detail information. It is	recommended to re-record your
   greeting message because the	new leakage will give better voice quality.

4. AT+VGT, This	command	sets the playing volume	of voice. The default value
   is 192, a higher value makes	the voice louder. The range of VGT is 0-255.



Improvement:

Modem

1. Endless retrain on S48.1=1 (data mode only) is fixed.

2. Performance on V.26bis dial-up line half-duplex mode	is improved.

3. In security call back mode, the DSR and DCD will turn on only after call
   back	has established.

4. In ATI2 response, ">100M" error message fixed.

5. Set s43.7=1 to fix DCE connection speed. Modem will disconnect if the line
   condition does not permit the highest speed set by AT&N command.

6. In EG+ model, Flash "!" function is modified	to be the same as in E+.

Voice

1. "AT+VLS=16" command used to get response of "OK", it	is corrected to	"VCON".

2. Sending the "ATH" command in	voice mode and off hook	state used to hang
   the modem, bug fixed.

3. Sending "AT&F" following the	command	"AT+FCLASS=8" used to gets "NO CARRIER"
   , it	is corrected to	"OK".


	       Firmware	6.11a release note	1-5-1994
	     -------------------------------


1.	Modem will fix line speed if the rate word from	remote modem only 
	indicates one speed capability.	 If remote modems tells	the ZyXEL, 
	it wants to maintain 1 speed only regardless of	phone line conditions,
	then the modem will not	try to retrain or fall back.

2.	Add delay before sending V42 XID frame after ADP detected. Maintain 
	compatibility with some	modem's 1200 bps V42 handshaking.

3.	With &M1, modem	will send asynchronous connect message before it 
	switches to synchronous	link.

4.	The problem of AA LED not blinking when	ringing	signal detected	is 
	fixed.

5.	V.33 compatibility improved.

6.	V.29 modulation	for 4W leases line modified.

7.	Fixed V.25bis in &D3 mode.

8.	Fax calling tone (CNG) will be terminated only after valid HDLC	frame 
	received.

9.	Solved QuickLink II fax	compatibility problem (fix DTE at 19200	on fax 
	mode by	S39.4=1).

10.	Parallel fax receiving problem (S38.4=1) fixed.	 The modem will	
	disconnect when	an incoming fax	is detected and	allow the fax machine 
	that is	connected to the ZyXEL to receive the fax.

11.	AT+fclass=8 will no longer reset voice parameters. 


12.	Implemented the	data calling tone detection in voice mode, <DLE>e.

13.	Implemented the	dial tone detection in voice mode, <DLE>d.

14.	Implemented an inactivity timer	in voice play mode, use	AT+VIT to set
	the timer between 0 and	255, the unit is in 1.0	second.

15.	Add VCON sensitivity configuration, use	AT+VVT to set the value
	between	0-255. A higher	value decreases	the sensitive. The default 
	value is 16.

16.	Add voice recording re-sync timer, use AT+VSY to set the timer
	between	0-255, the unit	is in 50 ms.

17.	In voice play mode, you	can use	the <DLE>p to pause and	<DLE>r to
	resume the voice play from data	buffer.

18.	In voice play mode, the	<DLE><CAN> command clears the transmit buffer
	of voice data in modem.

19.	In voice play mode, the	<DLE><DC4> command clears the transmit buffer
	of voice data then forces modem	to return to command mode.

20.	S48.2=1	enables	data CNG calling tone transmission.

21.	Set bit	1 of s48 to enable "Data Only" mode
 
	a.  auto detect	ZyX/V32bis/V32/V22bis/V.23/Bell	103/V.21 when 
	    answering
	b.  if handshaking of all speeds failed, modem continuously recycles
	    the	handshaking procedure until the	S7 timeout.

22.	Added #E1 to display line condition status.  You will have to drop
	down into command modem	while you are on-line with a +++.  Then	type 
	AT#E1.	Your terminal software will display only the line starting 
	with "*"
     
   CURRENT  Signal to	 Recieve    Retrain   Retrain	 Fast	 Fast  
   SPEED    Noise Ratio	 Level	    Granted   Requested	 RG	 RT   
   
*  16800    SN=XX.X	 RX=-XX.X   RG=XX     RT=XX	 FG=XX	 FT=XX

	
23.	In voice play mode, the	<DLE><FS> or <DLE><DC2>, resync	symbol,	resets
	the ADPCM coder	and still maintain continuity in the voice play	mode.

	    note:	* DLE =	0X10
			* DC2 =	0X12
			* DC4 =	0X14
			* CAN =	0X18
			* FS  =	0X1C




24.	New feature:  Extended Distinctive Ringing
 
Using Extended Distinctive Ring	with ZFAX

Extended Distinctive Ring (EDR)	is a special feature designed for home single
telephone line home use	to receive fax or data calls without interference with
regular	voice calls.  Most users when they install a fax/modem at home,	would 
not subscribe to one extra telephone line just for occasionally	fax or data 
calls; however,	fax/data calls do come from time to time.

If the user lets the fax/data software application answers the call, voice 
calls would be missed; on the other hand, if a person or answering machine 
answers	the call, fax or data call would be either missed or the person	who 
answer the call	has to go run to the computer to get this call to connect to 
the proper application.	 Either	way is not desirable.

What EDR can do	for users, once	enabled	with proper setting, are: 

1.	It can detect fax CNG tone without physically answering	the call.  
	Once the CNG tone is detected, the modem will report "RING" or 
	"RING n" to the	application software, thus the software	can tell the 
	modem to answer	the call.

2.	It can detect several DTMF tones without physically answering the 
	call.  The modem detects the DTMF tones, it will report	"RING" or 
	"RING n" to the	software application.

With these two functions, your ZyXEL can be installed with an answering	
machine	or telephone set at home.  In most cases, you would set	the modem to 
not report regular rings so the	software will not instruct the modem to	answer
the phone when it rings.  When a call comes in,	the answering machine will
answer the phone and play a voice message.  At this moment, the	modem once 
detecting the ring signal has gone will	start to listen	to the line for	CNG 
tone or	DTMF tones.   

If the remote caller is	an unattended fax machine which	sends out CNG tones 
for a period of	time, the modem	will detect the	CNG tone and report "RING" to 
software immediately.  The software application	can issue commands to answer 
the call and receive fax.  If the remote caller	is using a fax phone which 
does not send out CNG tones and	the caller is waiting for a fax	answer tone in 
order to press "START" buttom, the caller can then press a designate DTMF tone,	
which will activate modem to report and	consequently answer the	fax call.

This is	just one of the	applications that EDR can be utilized.	We have	
designed many different	ways to	set the	modem up not only to cover the basic 
usage but also for different extended applications. 



Setting	Up EDR

The new	EDR can	be used	at home	where multiple phones are installed parallel 
(normal	home telephone set-up with at least 1 extension).  Once	this function 
is enabled, the	modem will go into EDR mode after the ring disappears, where 
it will	be able	to detect CNG, *, 0, # and reports them	as different types of 
ring.
 
S-registers:
 
S51 bit	2-0
      000  EDR disabled
      001  EDR enabled,	single "RING" or "RING n" will be reported
      010  EDR enabled,	"RING" or "RING n" will	be reported twice
      011  EDR enabled,	"RING" or "RING n" will	be reported 3 times
      100  EDR enabled,	"RING" or "RING n" will	be reported 4 times
       :
       :
      111  EDR enabled,	"RING" or "RING n" will	be reported 7 times

S51 bit	5-3
      000  Disable CNG tone detection
      001  Enable CNG tone detection, reports as "RING"
      010  Enable CNG tone detection, reports as "RING 1"
      011  Enable CNG tone detection, reports as "RING 2"
       :
       :
      111  Enable CNG tone detection, reports as "RING 6"

S40 bit	6-3
      0000     To disable DTMF tone detection for EDR
      xxx1     To enable "*" detection,	and reported as	"RING"
      xx1x     To enable "0" detection,	and reported as	"RING 1"
	       or "RING" if only one type is enabled
      x1xx     To enable "#" detection,	and reported as	"RING 2"
	       or "RING" if only one type is enabled
      1xx0     To enable "*" detection,	and reported as	"RING 3"
	    (xxx1 has priority).
      You can enable more than one type	by turning on more than	one of the 
      3	bits.

EDR detection (either CNG or DTMF tone)	will be	disabled once it occurred.  
However, the customer's program might not answer because the sofware is 
waitng for a certain # of rings	before it will answer.	S51 bit	2-0 is used to 
control	the # of ring that modem will report once CNG tone or DTMF is detected.

The timing relationship	between	Caller ID (if enabled),	EDR and	the Ring 
detector are as	follows:


1'st        2'nd	 3'rd
on    off   on	  off	 on
   ****--------****---------****------------------------------------
		 3s	3s    3s    3s		   s7 timeout
   +------+----+-------+----+------+----+---------------------+----
   CID/EDR  RD	 EDR	RD    EDR   RD		EDR	       RD
 
	CID: Caller ID task
	RD : Ring Detector task
	SA : EDR task
 
Please remember	during EDR period, the auto baud function is disabled, issuing
a command at different baud might cause	the modem not to be able to response 
to any "AT" command.  Any AT command (assuming the command is accepted)	will 
also disable EDR function right	away. 

Application Example

Let's go back to the previous example where an answering machine is installed 
with a ZyXEL modem.  Say we use	ZFAX as	our fax	reception application, and we 
don't want it to answer the call unless it is a fax call.  The way to set it 
up would be:

1.    Set ZFAX to answer on 1 ring.
2.    Set S51.0=1 to enable EDR	and report "RING" once
3.    Set S51.3=1 to enable CNG	tone detection,	and reports as "RING"
4.    Set S40.4=1 to
      a.   enable Distinctive Ring type	2; and therefor	modem will not report
	   normal ring,	thus ZFAX will not answer call unless EDR reported
      b.   enable DTMF tone "0"	detection, and reports as "RING" in case the
	   remote fax machine does not generate	CNG tone.  In your answering
	   machine message you can ask fax call	to press "0" if	he (she) wants
	   to send a fax
5.    Save the settings	in a profile and reset the modem from this profile: 
      AT&W0Z0 for example.



       ********* ZyXEL Firmware Version 6.10 Release Note *****************



   1. V.42 Selective Reject feature is implemented and enabled as default,
      connect message is also changed. example: "CONNECT 57600/ARQ/V42b/SREJ.
      Reset bit 5 of S35 to disable Selective Reject.

   2. V.42 adaptive block sizing scheme is improved.

   2. V.29 4W leased line connection problem is fixed.

   3. Setting bit 5 of s39 will disable scrambler and discrambler in V.26
      operation.  This will make ZyXEL modem compatible with some old V.26
      modems which are not equipped with scrambler and discrambler.

   4. S39 bit 6 :   0 - The function of DTMF detection is enabled only
                        in PLAY or RECORD mode.

                    1 - The function of DTMF detection is enabled after the
                        command "AT+VLS=2" is sent.

                    Note : The function of AT auto baud detection is disabled
                           when the DTMF detection is enabled.

   5. S39 bit 7 :   0 - The recorded voice data do not include the resync
                        information.

                    1 - The recorded voice data include the resync
                        information in ADPCM mode.

                    Note: When the resync function is enabled, the modem  sends
                          a resync symbol -- DLE DC2 (0X10, 0X12), with voice
                          data every 50ms. Resync symbol resets the ADPCM coder
                          so that an ADPCM message can be edited without
                          continuity problem.


   6.   V.42 for 11-bit character length implemented.

   7.   ATDR response is quicker now.

   8.   Fix the problem of DTE speed being fixed at 19200 after setting
        AT+fclass=8.

   9.   Problem of garbled RING 1 message is corrected.

  10.   Problem of HS LED on at 300 bps connection is fixed.

  11.   Add "verify" action while entering new password.  New supervisory
        password has to be entered twice in order to save it to EEPROM.

  12.   E,7,1 data format password problem is fixed.

  13.   If S42.7=1 DCD only pulse off for 0.5 sec.

  14.   Add password protection, password can not be hardware reset when
        bit 6 of s35 is set in profile 0.

  15.   AT&Nxx*Q1 will fix modem speed at &Nxx selected. This requires both
        ends have the same setting.

  16.   If &D1 is set on leased line operation, DTR off will drop the connection
        ; DTR on will force handshaking and re-conncet the line.

  17.   Multiple page fax receiving problem with Cannon B200 solved.

  18.   Unused ROM space will be filled with FFs for programming efficiency of
        the EPROM programmer.

  19.   The ADPCM coding algorithm is modified. The file VCNVT.ZIP includes
        source code of the modified algorithm.


                      Firmware V6.01 release note
                    ===============================

1. set S48.0=1 will cause the CND to be displayed in raw data format.

2. Fixed fax fallback bug in V.29 mode created in previous version.

3. Supports Fax procedure interrupt in class 2 interface.

4. Accepts AT+FPTS=2 and AT+FPTS=3 class 2 command.

5. Restores 2-D receiving capability for ZFAX.

6. Makes it compatible with class 2 software that does not align EOL at byte
   boundary.

7. +fmdl? and +frev? act as version before 6.00.

8. S35.7=1 now correctly enable extended numerical result codes 30-39.

9. Accepts even parity, 7 data bit login password for type 2 password security
   operation.

10. ATZn resets fclass=0.

11. Improved error correction buffer flow control mechanism.

12. Adds a S-register S50 as the inactivity timer in 10-second unit. This timer
    counts when there is no data flow in or out of the RS-232 DTE serial port.




		     Firmware V 6.00 Release Note
		  ==================================


     1. Adds ZyXEL's proprietary 19.2 Kbps mode in Plus models. 19.2 Kbps
        mode is included in AT&N0 multi-auto mode.

     2. Supports turn-around polling-receiving & transmission procedure in
        class 2 fax commands.

     3. Supports multi-document procedure in calss 2 fax commands.

     4. ATS44.5=1 enables V.13 capability in synchronous mode.

     5. Fixes 4800bps fax recieving problem.

     6. Fixes hardware-dependent problem in CELP voice mode.

     7. Fixes 2-D transmission problem in fax mode.

     8. Corrects the RTN (Retrain Negative) response sequence in fax mode.

     9. Makes modem change back to data mode on fax mode hangup.

    10. V.42 buffer size has been adjusted to meet 1.2 sec echo delay over
        19200 bps link. Maximum number of outstanding frames for 128-byte
        frame is extended to 31.

        Original: (both transmit and receive paths)

	    if data compression disabled, 4K bytes;
	    if data compression enabled, 2K for uncompressed characters and
	    2K for compressed data.	

        Changed to: (both transmit and receive paths)

            if data compression disabled, 6k bytes;
            if data compression enabled, 2K for uncompressed characters and
            4K for compressed data.	

    11. Add S45, S46, S47 for Caller ID detection control as follows:

        S45: Guard time, the time interval for the modem to inhibit the
             silence detection metioned below after ring detection.

        S46: Silence interval, a continuous silence interval that the modem
	     must detect after ring detection before CND signal is to be
             processed.

        S47: CND gain, the gain of the modem's front-end while CND signal
	     is processed. Ranging form 1 to 255, 1 is the highest gain.

        S45 & S46 are in unit of 20 ms, default settings of them are:

	    S45 = 87  (1.75 second)
	    S46 = 3   (60 ms)

    12. Busy detection improved.

    13. Fixes capital "AT" detection bug after escape to command mode in
        previous version.

    14. Ringback (response "RINGING") detection improved.

    15. SLIP/PPP (UNIX program) bidirectional transfer performance improved.

    16. Has S18 define the modem's DTE RS-232 speed after every ring. The
        speed is fixed until overridden by an AT command. The definition of
        S18 is the same as that of S20. This feature is disabled if S18=0.
        Modem uses previous setting of speed when this feature is disabled.
        With this feature modem will have a fixed known DTE speed when
        answering. This is useful for shared modem use (by multi-tasks) like
        in some UNIX environments. Bit S38.3 may also need to be set to
        enable modem response receiving in this case.

    17. Adds one more DSR option:
	    AT&S1S41.5=1, DSR always on and off for 0.5 sec for DCD on-to-off
            transition.

    18. Default pulse dial make/break ratio for Ireland is &P1.

    19. 76800 bps AT autobaud detection improved on SUN SPARC station.

    20. Number of S registers has been increased to 60 for each profile.

    21. Echo delay measurement now is consistent on ATI2 and LCD display.

    22. $ command summary updated.

    23. One more status screen added to LCD display.

	   "  FG=  0   FR=  0   "
	   "  BR=  0   FE=  0   "

	   FG: Number of FRN (Fast Rate re-Negotiation) request Granted
	   FR: Number of FRN Requested
	   BR: Number of Blocks Retransmitted
	   FE: Number of FCS (Frame Check Sum) Errors (block errors)

    24. ATI will only return numeric response "1496".
        Product information has been appended to ATI1.

    25. S44.3=1 enables cyclic dial, ATDSn will start dialing the phone
        number stored in memory location n, if not successful it will cycle
        dial through all the numbers stored in memory.

    26. The bit of S35.6 of each profile will enable password protection for
        that profile. When issuing "AT&Wn" and the bit of S35.6 of profile n
        is set, supervisory password will be requested.

    27. S35.7=1 enables extended numerical result codes to indicate if an
        error control connection is made, used with ATV0. Result codes 30-39 
        are added. Refer to new quick reference card soon to be released for
        detail.

    28. New mode for &B1 with S44.6=1:
        DTE speed fixed at current speed when an error controlled connection
        is made and DTE speed follows the link rate when a non-error-
        controlled connection is made (as &B0).



		 Firmware 5.05c Release Note
	       ------------------------------

	1. Add CR/LF on the end of response message to correct 5.05 BBS
	   receive fax problem. The same solution could be made by using
	   RCVFAX ver 2.2 .

	2. Correct sometimes hang on fax "DIALING" after remote busy was
	   detected.



		 Firmware 5.05 Release Note
	       ------------------------------

       1. Fixed V.23 connect problem.

       3. Correct the ring back detection problem for short-short ring.

       4. Modify 16.8 Kbps retrain procedure for more smooth operation.

       5. Enhance the receiving capability of the Caller-ID signal.

       6. Calling tone extended to wait remote fax answer.

       7. Accept remote "RESET" V.42bis request. ( USR &Y0 setting )

       8. Improved reliability of error control handshaking ( MNP or V42 )
	  especially with another ZyXEL 5.04d or above.

       9. Solved the connection problem with MicroSoft BBS which is using
	  Telebit T3000.

      10. When issuing ATSr.b? will no more get "ERROR" response.

      11. Improve the reliability of the DTMF detection in voice mode.

      12. Add 'BUSY' & 'RINGING' response in ATD command when AT+FCLASS=8
	  is issued.

      13. When modem set &B0s44.6=1, the DTE speed will fix at 19200 if
	  the connection speed above 9600.

      14. Solved DTR, RTS both active within 5 micro sec and only one be
	  recongnized.



		    Firware V5.04 release note		 11/13/1992
		   ----------------------------

   1. Add "COMMAND ECHO", "RESULT CODE", "DTE ASYNC SPEED"
      "PANEL LOCK" and LED status slection screen to LCD model.

   2. Add AT*I2 ( dumb mode ) command.

   3. If bit 2 of s44 is set, dial backup will not automatically start.
      When the leased line broken, modem will still trying leased line
      and shows "DIAL BACKUP ?" wait for someone to press a key to start
      dial backup. This modification for U-1496, U-1496R only.

      This will prevent useless dial-up connection when there is no data
      flow on the line.

   4. Capable to receive destructive break in V.42 bis now.

   5. Flow control can be recovered after return from online command mode.

   6. Modem will hangup correctly if the DTR and RTS drop at the same
      time.

   7. Correct compatibility problem with USR modem/fax.

   8. V.13 function is added. Bit #5 of s44 is used to enable this function.
      Default is 0 (disable).

   9. Can be used on hardwares with different transmission gain.

  10. Can detect short period busy tone in voice mode.

  11. Can catch caller ID without enlarge the gain of AGC amplifier.

  12. Reduce the click sound at the beggining and the ending of the voice
      mode operation.

  13. Bit #5 of s35 is used to provide 6 db attanuation of the transmiting
      power in leased line operation.

  14. For new zealand version, correct ring back to be detected as busy
      problem.

  15. Correct DIS pattern error (ECM bit is set) in fax mode.

  16. If bit 6 of s35 is set, all the "save" profile command need password
      checking. U-1496 "SAVE TO" option can not be changed either.


			Firmware 5.02 release note
	  -----------------------------------------------------------

	1. "RINGING" response is restored, set bit 6 of s42 can disable
	   this function.

	2. Fast Rate re-Negotiation fall back/forward range change from
	   16800-7200 to 16800-4800.

	3. Improve the silence/quiet detection in voice mode.

	4. Fix caller ID & distinctive ring bugs.

	5. Can send to fax machine which has no answer tone.

	6. Correct response messages associated with ATX2 & ATX3

	7. Fix compatibile problem with some fax machchine which can
	   not response to MPS signal correctly without some delay between
	   fax message and MPS.

	8. Austra version add 120 ms flash time.

        9. Japan version add 20 pps pulse dial and ring detector spec.

       11. Correct remote digital loopback problem in async non error
	   control mode.

       12. Correct frequency range problem of ring detector.

       13. Correct 1300 Hz calling tone to be recognized as fax calling tone
	   problem.


       ********* Firmware Version 5.01   Note *****************


       1. Increase voice playback volume.

       2. Correct busy tone detection in voicce mode.

       3. Correct 16800 EMSI-session error when using frontdoor to file
          request.



       ********* Firmware Version 5.00   Note *****************


    Bugs fixed:

         1. Fix fax handshake problem for NeXT COMPUTER.

         2. Fix bad scan line problem in fax transmitting when
            zero-filling is necessary due to underflow of
            phase C data.

         3. AT+fclass=2 will set fax mode in any condition when call out.
            Switch back to modem mode you have to issue AT+fclass=0 or
            AT&f or ATZn.

         4. ATM3 can not work properly. This bug has been fixed.

         5. Call back security ( *G3, *G4, *G5) can not work properly in
            MNP mode. This bug has been fixed.

         6. Remove forcing s0=3 in swiss version firmware.


    New features and commands:

         1. Add ZyXEL proprietary 16.8 k mode. If X7 is selected, the
            connect message will like "CONNECT  16800/ARQ/V42b/ZyXEL".
            *Note: This feature only available in 1 Mega EPROM.
            *Note: This message will cause problem if your BBs also for
                   automatic fax receiving because the " ZyXEL " message causes
                   the mailer switch to fax receive mode. Please use X6 in this
                   case.
                   Because of this problem, the V5.00 released after Aug. 11,
                   1992 has removed the final /ZyXEL wording in the connect
                   message.

         2. Add VOICE mode according to TR-29.
            *Note: This feature only available in 1 Mega EPROM.

         3. Add fax polling feature ( AT#B2 ). ZFAX 2.0 support this
            feature.

         4. ATSr.b?   ----- Display bth bit value of rth S register.
                            r = 0-49
                            b = 0-7

         5. AT*T ----- Recall last CND message.

         6. U-1496 LCD model can instantly display CND message on LCD
            panel and replay CDN message by pressing "LEFT" arrow at
            CONFIG screen or by pressing "RIGHT" arrow at "DIAGNOSTIC"
            screen.

         7. Set bit 7 of S17 will put modem into dumb mode. ( ATS17.7=1 )



       ********* Firmware Version 4.09h  Note *****************
						    Date:06/15/92

  New Change

  1. "W" has to detect 1.5 seconds continous dial tone.
     WAS : 3 seconds.

  2. Start restoral operation (lookback leased line) without disconnect
     dial-up line.
     Was : disconnect dial-up line.

     This change will only effect on PCB REV6, REV8 or modified REV9, REV10 and
     REV10A. Otherwise it will work as old way. Only U-1496 affected.


       ********* Firmware Version 4.10	 Note *****************
						    Date:06/23/92

  1. CPM ( Call Progress Monitering ) scheme changed for some country's PTT
     regulation.

  2. V.17 training procedure changed to quick ( short ) train. Reason for this
     change is to be compatible with most of 14400 fax machine.

    *** Note ***

     Firmware before 4.10 may not receive fax properly from version newer than
     4.10. Set bit 4 of s42 will force modem to use V.29 9600 to transmit fax
     for compatible with version before this version.

  3. In leased line operation if V.22bis handshaking fail modem will disconnect
     the line and restart handshaking.


  4. New features added

     Caller-ID and Distinct ring are added but only avaible on 1 Mega ROM code
     now.



       ********* Firmware Version 4.11	 Note *****************

						    Date:06/29/92

   1. Set bit 3 of s42 will disable the Escape function in answer mode.

   2. Bug fixed

      Leased line direct async mode ( without buffering ) handshaking fail.
      This bug fixed.


       ********* Firmware Version 4.12	 Note *****************

						    Date: 7/01/92


   1. Response corrected for +fdcc=?, +fdis=?.

   2. Response corrected for +frev?, +fmdl? . The response is the same as ATI
      issued.

   3. Support Quick Link II software now. Only at&f need for init string.

   4. Accept AT command after ;.
      Ex. atd1234;h0 .

      In this example modem will dial 1234 then hang up.

   5. Any non-digit nor modifier in the dialing string will be ignore and will
      not cause ERROR response.

   6. Disable showing "Dialing..xxxx" on terminal if Q1 or V0 is set.

   7. Clear ring count after 8 second with no ring coming has extend to 10
      second for catching incoming ring which has long pause between each ring.


       ********* Firmware Version 4.12b  Note *****************

						    Date: 7/06/92
   Bugs fixed

   1. Malfunction on V.25bis auto answering from version 4.12.

   2. When 108/2 = ON, modem did not turn on 106 to signal DTE that it
      is ready to enter the dialogue with the DTE.


   Performance improved

   1. Buffer 1 scan line before transmitting fax data. This will prevent data
      lost when transmitting a fax to a 14400 fax machine.


   New command added

   1. ATSr.b=n	 ----- Set or clear one bit of S register, others bit value
		       are not affected.
		       r = 0-49
		       b = 0-7
		       n = 0-1

		       Exp. : Set bit 5 of s38 ( disable MNP5 )

		       ATS38?
		       000
		       OK
		       ATS38.5=1
		       OK
		       ATS38?
		       032
		       OK


       ********* Firmware Version 4.12c  Note *****************

						    Date: 7/07/92
   Bugs fixed

   1. From V 4.10 and 4.12 will cause incorrect control instruction. It is a 
      new bugs from V 4.10 only U-1496 LCD model affected.

   2. Auto-answer malfunction at DTE speed under 19200 is corrected.
      This is a new bug from 4.12.



       ********* Firmware Version 4.09h  Note *****************
						    Date:06/15/92

  New Change

  1. "W" has to detect 1.5 seconds continuos dial tone.
     WAS : 3 seconds.

  2. Start restoral operation (lookback leased line) without disconnect
     dial-up line.
     Was : disconnect dial-up line.

     This change will only effect on PCB REV6, REV8 or modified REV9, REV10 and
     REV10A. Otherwise it will work as old way. Only U-1496 affected.


       ********* Firmware Version 4.10	 Note *****************
						    Date:06/23/92

  1. CPM ( Call Progress Monitering ) scheme changed for some country's PTT
     regulation.

  2. V.17 training procedure changed to quick ( short ) train. Reason for this
     change is to be compatible with most of 14400 fax machine.

    *** Note ***

     Firmware before 4.10 may not receive fax properly from version newer than
     4.10. Set bit 4 of s42 will force modem to use V.29 9600 to transmit fax
     for compatible with version before this version.

  3. In leased line operation if V.22bis handshaking fail modem will disconnect
     the line and restart handshaking.


  4. New features added

     Caller-ID and Distinct ring are added but only avaible on 1 Mega ROM code
     now.



       ********* Firmware Version 4.11	 Note *****************

						    Date:06/29/92

   1. Set bit 3 of s42 will disable the Escape function in answer mode.

   2. Bug fixed

      Leased line direct async mode ( without buffering ) handshaking fail.
      This bug fixed.


       ********* Firmware Version 4.12	 Note *****************

						    Date: 7/01/92


   1. Response corrected for +fdcc=?, +fdis=?.

   2. Response corrected for +frev?, +fmdl? . The response is the same as ATI
      issued.

   3. Support Quick Link II software now. Only at&f need for init string.

   4. Accept AT command after ;.
      Ex. atd1234;h0 .

      In this example modem will dial 1234 then hang up.

   5. Any non-digit nor modifier in the dialing string will be ignore and will
      not cause ERROR response.

   6. Disable showing "Dialing..xxxx" on terminal if Q1 or V0 is set.

   7. Clear ring count after 8 second with no ring coming has extend to 10
      second for catching incoming ring which has long pause between each ring.



	********* Firmware Version 4.09c  Note *****************
						     Date:05/16/92

   Bug fixed

   1. V.22 bis calling tone ( 1300 Hz, some peple say V.25bis guard tone ) can
      trig U-1496 modem to switch to fax receiving. This bug fixed.

      Only 1100 Hz ( FAX calling tone ) will switch modem to fax receiving.
      Thers is no need to set bit 7 of s41 now.

   2. Two multi-auto modem handshake to 2400 or fail if answer end delay to
      answer ( Example: answer machine ahead ).

   3. Fax calling tone stop when the other end off hook or voice answer.


   New Change

   1. 100 ms delay changed to 480 ms delay after dial tone detected to dial
      first digit. Some slow PBX need this delay to handle first digit.


	********* Firmware Version 4.09d  Note *****************
						     Date:05/23/92

   1. Add compatibility with some Nokia ECM 4896.


	********* Firmware Version 4.09f  Note *****************
						     Date:05/24/92


   1. Reset serial port speed according the value of s18 after DTR drop when
      &D3 and s38=8 was set.


	********* Firmware Version 4.09g  Note *****************
						     Date:05/24/92

   Performance improved

   1. V.23 can survive 3002 channel now.
   2. Less burst data to DTE now. This could reduce the errors when high DTE
      speed chosen and no 16550 used.

   Bug fixed

   1. AT+FAA=0 could be saved to profile, this bug fixed. The default value
      always 1, if you want to change the value you have to issue command

   New Change

   1. Two rings comes within 1 second will be recongnized as only 1 ring.
   2. Double the time of scan line (space stuffing) for some fax machine
      without buffer or with slow print head.
   3. Decrease the sensitivity threshold to initiate Fast Rate re-Negotiation
      to against slight gain hit, impulse noise and frequency shift.


	********* Firmware Version 4.09c  Note *****************
						     Date:05/16/92

   Bug fixed

   1. V.22 bis calling tone ( 1300 Hz, some peple say V.25bis guard tone ) can
      trig U-1496 modem to switch to fax receiving. This bug fixed.

      Only 1100 Hz ( FAX calling tone ) will switch modem to fax receiving.
      Thers is no need to set bit 7 of s41 now.

   2. Two multi-auto modem handshake to 2400 or fail if answer end delay to
      answer ( Example: answer machine ahead ).

   3. Fax calling tone stop when the other end off hook or voice answer.


   New Change

   1. 100 ms delay changed to 480 ms delay after dial tone detected to dial
      first digit. Some slow PBX need this delay to handle first digit.




	********* Firmware Version 4.08a release note *********
						     Date:04/25/92

   1. In the V.25 bis command state, CTS will follow the DTR signal.

   2. In the V.25 bis command state, modem ignore (no parity checking) the
      8th bit of 8-bit data unit within message frame.

   3. Add RST command for V.25 bis to switch back to async AT command mode.

   4. If bit 6 of s41 was set (s41=64), ATS0=1 is forbiden. Modem will
      answer after the second ring.

   5. FAX performance under TAS 3002 channel is improved.

   6. FAX carrier lost detection is improved.

   7. Deviation in echo cancelation measurement is corrected.

   8. Support AT+FAA?, AT+FAA= now.

   9. Note: If AT+FCLASS=2 has been issued to send or receive FAX, you must
	    issue an AT+FCLASS=0 to initiate a data call.


	********* Firmware Version 4.08b release note *********
						     Date:04/30/92

   1. Detection improved in multi-auto call 2400 modem.



	********* Firmware Version 4.09a  release note *********
						     Date:05/07/92

   Bug fixed

   1. HS LED stays on during V.22bis connection.
   2. Spurious <CR> send to DTE, which cause WINFAX start to wait response,
      if no response return from modem an error message appear " NO COMMUNICA-
      -TION FROM MODEM".
      The other way to solved the problem is to reduce modem timeout interval
      by adding ats7=30 to the init string. Default is 60 seconds.
   3. Remote config can not work properly.


   New change

   1. ATI1 can display the checksum in decimal now.
   2. Set bit 7 of s41 ( = 128 ) disables calling tone detection ( switch to
      FAX ). This can be compatible with some V.22bis modem which generate
      calling tone when dialing.
   3. This version compatible with SuperFax 5.0 now. But you have to save &C0
      to profile 0 before runnig it. SuperFax will not issue commands if CD
      not present.






	********* Firmware Version 4.08a release note *********
						     Date:04/25/92

   1. In the V.25 bis command state, CTS will follow the DTR signal.

   2. In the V.25 bis command state, modem ignore (no parity checking) the
      8th bit of 8-bit data unit within message frame.

   3. Add RST command for V.25 bis to switch back to async AT command mode.

   4. If bit 6 of s41 was set (s41=64), ATS0=1 is forbiden. Modem will
      answer after the second ring.

   5. FAX performance under TAS 3002 channel is improved.

   6. FAX carrier lost detection is improved.

   7. Deviation in echo cancelation measurement is corrected.

   8. Support AT+FAA?, AT+FAA= now.

   9. Note: If AT+FCLASS=2 has been issued to send or receive FAX, you must
	    issue an AT+FCLASS=0 to initiate a data call.


	********* Firmware Version 4.08b release note *********
						     Date:04/30/92

   1. Detection improved in multi-auto call 2400 modem.



	********* Firmware Version 4.08a release note *********
						     Date:04/25/92

   1. In the V.25 bis command state, CTS will follow the DTR signal.

   2. In the V.25 bis command state, modem ignore (no parity checking) the
      8th bit of 8-bit data unit within message frame.

   3. Add RST command for V.25 bis to switch back to async AT command mode.

   4. If bit 6 of s41 was set (s41=64), ATS0=1 is forbiden. Modem will
      answer after the second ring.

   5. FAX performance under TAS 3002 channel is improved.

   6. FAX carrier lost detection is improved.

   7. Deviation in echo cancelation measurement is corrected.

   8. Support AT+FAA?, AT+FAA= now.

   9. Note: If AT+FCLASS=2 has been issued to send or receive FAX, you must
	    issue an AT+FCLASS=0 to initiate a data call.




	********* Firmware Version 4.07 release note *********
						     Date:04/10/92


   1. For U-1496E and U-1496R, HS LED is not only to indicate Hi-speed
      (above 2400) or Lo-speed. It also indicate

	a. After power on, the HS LED will flash to indicate initialization
	   is going on.
	b. HS LED will flash regularly (half sec ON, half sec off) at dialing,
	   handshaking, and retrainning. When Fast rate Re-Negotiation occurs
	   the HS LED will also flash. If negotiation failed, HS LED will go
	   flash periodically (retrainnig).

   2. Improve the perfomance ON HSLINK bidirection file transfer.

   3. Disable dial tone detection if bit 4 of s41 is set, no matter what
      X setting is.

   4. Improve the compatibility with Nokia ECM 4896.

   5. Bit 2 of s41 is set, modem will keep trying to handshake with remote
      modem up to 3 minutes before dropping the carrier.

   6. Lowest rate of Fast rate Re-Negotiation will be limited to 7200 due
      to the equal performance of 7200 and 4800.


        ********  Release Note for Version 4.06  *************

 1. Function Updated

        a. Speed conversion implmented, accept any DTE speed in V.23 now.

        b. Update the rate renegotiation forward mechanism.

        c. Update the fax compatability with BitFax V3.06, 3.07.
           ( please set the bit 3, 4 of s39 and save to to profile 0, s39=24 )


 2. Bug fixed

        a. Fix the bugs of V.25bis command.

        b. Solve the problem of using 'W' command to wait second dialtone
           for forwarding call.

RELEASE NOTE R405

ADDED FEATURES:

1.  ATQ2 ADDED, NO RESULT CODE IN ANSWERING MODE

2.  FAX PERFORMANCE IMPROVED

3.  HARRIS FAX COMPATIBILITY

4.  ATDL SHOWS DIALING NUMBER

BUGS FIXED:

1.  AT&D3 RESET DELAY IN TAKING COMMAND

2.  FIX IN SECURITY PROFILE SAVING

3.  DIALING DELAY FIXED

4.  57600 DTE COMMUNICATION PROBLEMS FIXED


        ********  Release Note for Version 4.04  *************

 1. Function Updated

        a. Include the zero-fill feature for class 2 fax.

        b. Cancel the "CED" response in call mode of class 2 fax

        c. Compatabile with MicroLink for Windows now.

        d. Accept "ATD" command when the modem is ringing.

        e. In call mode, the connect DCE speed will not execeed
           the DTE speed.

        ********  Release Note for Version 4.01  *************

 1. Problem Fixed :

        a. Improve the performance on the lines with strong listener echo.

 2. Function Updated

        a. Expand the number of S-register to 50 (S0-S49). The modem
                will load factory default at the first power on. Please
                record your own current profile to avoid loss of your
                settings. After that, the modem will work as normal.

        b. Add the feature to disable throughput average (Bit 0 of S40).
                In default, the modem will average the thruput output to the
                DTE to avoid the burst data flow.
                If you set this bit, the modem will not average the thruput
                and transmit data to DTE without any delay.

                !!! Warning : It is not recommended to set the bit 0 of S40
                                if your PC is not fast enough or without
                                16550.

        ********  Release Note for Version 4.00  *************

        These notes is accumulated from version 3.95


 1. Problem Fixed :

        a. Improved the fax auto detection compatability.

        e. Solve the compatable problem with 303-444-7791 (T2500, 9600).

        c. Change the screen display to "Loading Default" when hardware reset
                in LCD model.

        d. Solve the problem of "PHASE D ERROR" when using BitFax, please
                set the bit 3 and 4 of S39 to be 1 (S39=0X18) if you want
                to use BitFax.

        e. Compatablity problem with some 2400 MNP5 modems. (CompuCom ...)

        f. Non-Error control mode BREAK function is added.

        g. Solve the problem of V42 protocol error.

        h. Solve the compatable problem with 212-427-1805 (Hayes, 2400).


 2. Function Updated

        a. Add the CCITT V.23 1200/75 mode.

        b. Add the level 2 security function.

           ;----------------------------------------------------------------
           Newest security function command set :

           + *G0                      Disable security function

             *G1                      Enable level 1 secutity, with password
                                      check.
             *G2                      Enable level 1 security, with password
                                      check and call back.
             *G3                      Enable level 2 secutity, with password
                                      check.
             *G4                      Enable level 2 security, with password
                                      check and call back.
             *G5                      Enable level 2 security, with password
                                      check and call back, remote site enter
                                      the call back number.
                NOTE:
                      1. The command *Gn needs password checking.
                      2. In security level 1, the remote site must be a ZyXEL
                         modem.
                      3. In security level 2, the remote site can be any other
                         modems.
                      4. Modem can store 10 sets ( 0-9 ) of telephone number.
                         If call back security disabled, modem will search the
                         password table to check the remote modem's password.
                         If match, modem will keep connected, otherwise modem
                         will hangup the phone. If call back security enabled,
                         modem will complete security checking, if not match,
                         modem will just disconnect the line, otherwise modem
                         will discoonect the line then find the telephone
                         number and call back immediatly. Remote modem will
                         auto-answer the phone and response otherwise modem
                         will disconnect the line.


        c. In class 2 mode, the DTE speed will keep in constant after
           the response "AT+FCON".

        d. If you are using BitFax, please save the bit 3 of S39 to be 1,
           and save it to the profile 0.

        e. If you are using BitFax for windows, please add the string
           "ATE0" into the dialing prefix in the transmit section of setup.

        f. Change 'ESC ESC' responese with 'ZyXEL' in BBS fax receiving
           function.

        g. Restore DTE speed when fax receiving is finished.

 3. Note for BBS SysOp :

        To make your BBS receive the incoming FAX, you need to change the
                following setup :

                1. Add the string "#B1+FCLASS=6" into the init string. Be
                   sure that the "+FCLASS=6" must be the last command.
                2. change one of the connect message list to be "CONNECT FAX".
                3. set the external mail string need to be set as "ZyXEL".
                   Give this external an error level to shell out to dos.
                3. in your BBS batch file, if the error level matches the
                   external mail, execute "rcvfax comport workpath" or
                   "rcvtif comport workpath".
                4. Now, you can use U1496 to receive a fax in your BBS.

        1. The following is a sample setting in the frontdoor system :

                Add in the init String : X7#B1+FCLASS=6

                        ÕÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ Messages ¸
                        ³ 300         CONNECT|         ³
                        ³ 1200        CONNECT 1200     ³
                        ³ 1275        CONNECT FAX      ³
                        ³ 2400        CONNECT 2400     ³
                        ³ 4800        CONNECT 4800     ³
                        ³ 9600        CONNECT 7200     ³
                        ³ 19200       CONNECT 9600     ³
                        ³ 38400       CONNECT 14400    ³
                        ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ

            ÕÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ External Mail ¸
            ³      String                       Error Level         ³
            ³ 1    ZyXEL                           100              ³
            ³ 2                                                     ³
            ³ 3                                                     ³
            ³ 4                                                     ³
            ³ 5                                                     ³
            ³ 6                                                     ³
            ³ 7                                                     ³
            ³ 8                                                     ³
            ³ 9                                                     ³
            ³ 10                                                    ³
            ÀÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ


        2. For the Binkley User, add the following string into the file
           "binkley.cfg" :

                Init    AT&FX7s0=1#b1+fclass=6|
                ExtrnMail ZyXEL errorlevel



	********* Firmware Version 3.94 release note *********
						     Date:12/09/91


    -  Leased line performance improved





        ********* Firmware Version 3.93 release note *********
                                                     Date:12/03/91

Bug Corrected :

    - Correct Fax image overwritten problem in V.17 mode.

    - Correct scan time problem in AT+FDIS command.

    - Correct temperature defect problem.

    - Correct fax 7200bps speed report problem in class 2 command set.

    - Correct Break handling problem.

    - Correct the compatability problem with the fax 1-212-566-1424.

    - Correct the problem of ';' character in class 2 command set.


Function Updated :

    - It is no need for DTE to add a delay time before sending class 2
      commnad to DCE after 'OK' is received.

    - Add AT+FDCC? command.

    - Add the following features for Next Computer, by set bit 3 of s38:

         . CD turns on 250 ms before 1'st message sent to DTE and turns
           off after all messages is sent to DTE.

         . send 'CONNECT FAX' to DTE before '+FCON' in receiving fax.

         . use S18 to control DTE rate in answering call.

         . Use ASCII characters in +FHNG response, instead of neumerical code.

         . Bisync protocol is always adopted in fax receiving data.

    - &D3, anytime lower DTR will cause modem on hook and load profile 0.

    - If bit 0 of S38 was set to 1, modem will repeat dialing default number
      utill the connection is made. Press any key from keyboard or panel
      (U-1496S) during dialing or handshaking will abort this function.

    - For U1496S, panel lock will not lock screen moving anymore but it will
      inhibit parameters change.


                  Firmware Version 3.90 release note
                --------------------------------------

       1. Fax class 2 interface (TR29.2) is implemented to support
          WinFax, BitFax & Fax96 software.

       2. Solve compatibility problems with some fax machine.

       3. Add AT#B1 command for BBS fax receiving application. This command
          also change CONNECT 12000/ARQ to CONNECT 9600/ARQ.

       4. Add AT+FClASS=6 for ZFax application

       5. Auto-mode fax receiving can be disabled by setting bit #4 of S38
          (sendfax only).

       6. Add X7 command. Ex.  14400/ARQ/V42b

       7. Add &D3 command. It will load profile 0 after DTR drop (hang up).

       8. Factory default setting &D0 replace by &D2.

       9. V.17 14400 bps FAX implemented.

      10. MNP5 can be always disabled by setting bit 5 of S38.

      11. CD can be on before the connect message is sent and can be off
          after disconnect message is sent ( in fax mode) by setting
          bit 3 of S38.

      12. Improve the performance of detection of carrier loss in Dialup and
          2-W lease line.

      13. Fix the bug of MNP compatability with USR Courier HST (This is an
          old version without MNP4).

      14. Fixed the Bug of data format 1,7,2 (1 start, 7 data, 2 stop) has
          been fixed.




		  Firmware Version 3.89 release note
		--------------------------------------

       1. Fax class 2 interface (TR29.2) is implemented to support
	  WinFax, BitFax & Fax96 software.

       2. Solve compatibility problems with some fax machine.

       3. Add AT#B1 command for BBS fax receiving application. This command
	  also change CONNECT 12000/ARQ to CONNECT 9600/ARQ.

       4. Add AT+FClASS=6 for ZFax application

       5. Auto-mode fax receiving can be disabled by setting bit #4 of S38
	  (sendfax only).

       6. Add X7 command. Ex.  14400/ARQ/V42b

       7. Add &D3 command. It will load profile 0 after DTR drop (hang up).

       8. Factory default setting &D0 replace by &D2.

       9. V.17 14400 bps FAX implemented.

      10. MNP5 can be always disabled by setting bit 5 of S38.

      11. CD can be on before the connect message is sent and can be off
	  after disconnect message is sent ( in fax mode) by setting
	  bit 3 of S38.



                       V 3.85 release note   9/10/91
                      ======================

      1. S3 register can not be modified: This has fixed.

      2. Function for ANS and ORG reversed (E model): This has fixed.

      3. V42 ODP phase has reduced 160 ms in order to compatible some
         non-error control 2400bps modem's application.

      4. MNP4, V42 option disable data compression.
         MNP5, V42bis option enable data compression.

      5. ATA, ATH1 function abnormal in on-line command state: This has fixed.

      6. ATH, ATH1 tingling no more.

      7. Panel lock modified (U-1496): When panel locked enabled (AT*L1),
                                       press LEFT and RIGHT key together
                                       will toggle panel lock on and off.

      8. DTE off: Add 5 ms debunce to make sure DTR is droped.

      9. Ignore old and uncompatible MNP request (some Acer 2424).

     10. CTS will follow RTS in sync mode (off-line) if CTS FOLLOW RTS
         selected.

     11. In leased line operation, MULTI-AUTO will be forced to V32bis.

     12. ATQn, ATEn need seperately config now.

     13. Remote config function abnormal in error control mode: This has
         fixed.

     14. pattern will not generate in data format E,7,1 analog loopback
         self-test: This has fixed.





    Firmware version 3.85 has been released with following change :

    1. S3 register can not be modified bug fixed.
    2. Error Control Option V.42 will not include MNP5 data compression
       from this version.


		       V 3.81 release note   9/10/91
		      ======================

      1. Pulse dial: inter-digit interval change to 900 ms

      2. Solve compatibility problem with Codex V.32bis modem

      3. Add new adaptive rate mechenism to combat some bad quality line

      4. Solve compatibility problem with 2-D fax machine

      5. Correct E-model lease-line transmission power

      6. Solve compatibility problem with fax-machine which has no answer tone
	 (voice answer)

      7. Carrier lost detection improved (within 5 secs)

      8. Speaker control (ATM0) bug fixed

      9. Fix MNP3 bug

			V 3.80	release note
		       ----------------------

   1. Improve Remote Digital loopback performance

   2. Correct speaker volume control bug

   3. Correct V.42 compatibility with USR 9600 DS

   4. Improve V.42 bis throuthput




    Firmware version 3.3 has been released with following change :

    1. FAX performance improved in long delay and strong echo condition.
    2. Clock is provided when synchronous mode is selected.
    3. Asynchronous 2/W leased line will check FCS error counter to
       determine whether the line was been disconnected and restart
       handshaking ( include error-control level ).
    4. Async Direct mode ( No buffering ) implemented.
    5. V.22 bis analog loopback test implemented.
    6. V.42 bis implemented
    7. AT command changed

       AT&K3: enable V.42
       AT&K4: enable V.42 bis
       AT&K5-6: discarded
    8. Phone number set has been added to 10 ( 0-9 ).
    9. New command added


        1. *F0      Deny remote configuration. (Default)
        2. *F1      Accept remote configuration. ( and Remote Digital loopback
                    must be granted---AT&T4 )

        3. *G0      Disable security function
        4. *G1      enable level 1 secutity. ( password check )
        5. *G2      enable level 2 security. ( password check and call back )
                    ** These commands need password checking.

                    Modem can store 10 sets ( 0-9 ) of telephone number. If level
                    1 security enabled, modem will search the password table to
                    check the remote modem's password. If match, modem will keep
                    connected, otherwise modem will hangup the phone. If level 2
                    security enabled, modem will complete level 1 checking, if
                    not match, modem will just disconnect the line, otherwise
                    modem will discoonect the line then find the telephone number
                    and call back immediatly. Remote modem will auto-answer
                    the phone and response otherwise modem will disconnect the
                    line.

        6. *HS      Modify supervisory password.
           *Hn      Modify user password. ( n=0-9 )
                    ** These commands need password checking.

                    Any charcter could be entered as a password ( 0-255 ).
                    Maximum characters for password are eight.

        7. *Rab     Read remote configuration to local profile.
                    a= 0-3, local user profile
                    b= 0-3, remote user profile
                       4  , remote current configution.
                       5  , remote factory default.
                    ** These commands only work at on-line condition and no
                       matter async or sync remote site use.

        8. *V       View password table.
                    ** This command needs password checking.

        9. *Wab     Write local user profile to remote user profile and reset
                    remote modem from that profile.
                    a=0-3 , local user profile.
                    b=0-3 , remote user profile.
                    ** These commands only work at on-line condition and no
                       matter async or sync remote site use.

        ** Default supervisory password is "ZyXEL".

        Security function can only modified at terminal mode. Remote configuration
        can also control from panel. But you have to set "RDL REQUEST=GRANT", bit 0
        of s36 to be 1 at to be cotroled site. Set bit 1 of s36 to be 1 ( read )
        or 0 ( write ) and s37 bit 0-3 to be remote profile, bit 4-7 to be local
        profile at initiator site.

        *******************************************************************

        ZFAX utility 3 : editfont.exe

        You can use this utility to edit the ZyXEL fax font, zfax.fon.

        You can only execute this program on the EGA or VGA monitor.

        After execute this program, enter the source char and dest char,
        you can use the combination of alt and number key to enter the
        special ascii code.

        While editing, there are three different modes to edit the font.

                Normal : press ENTER to toggle the bitmap color, use
                         cursor key to move the crossbar cursor.

                Insert : In this mode, the bit that crossbar cursor pass
                         will have a mark color.

                Delete : In this mode, the bit that crossbar cursor pass
                         will have a blank color.

        Use the "INSERT" key to change these three modes.

        After editing each char, press "ESC" to quit without save or "F2" to
        save this change.