1087 lines
45 KiB
Plaintext
1087 lines
45 KiB
Plaintext
Demon Internet Ltd
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==================
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Gateway House
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322 Regents Park Road
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Finchley, London, N3 2QQ
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0181-371 1234 (Sales - London)
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0131-552 0344 (Sales - Edinburgh)
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0181-371 1010 (HelpLine)
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0181-371 1150 (Fax)
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0181-371 1000 (Switchboard)
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email internet@demon.net
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MODEM.TXT - INFORMATION ON CONFIGURING A MODEM FOR CONNECTING TO THE
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INTERNET
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Last updated: 19 April 1995
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The latest version of this document is available from
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ftp.demon.co.uk:/pub/doc/Modem.txt
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Contents
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========
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1. General
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2. Essentials
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3. Telephone Exchange
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4. Internal Modems
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5. Which Phone Number
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6. Modem and Telephone Leads
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7. Serial Chips
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8. Speed
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9. Trouble Shooting
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10. Software and Other Factors
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11. Help for Specific Computers
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11.0. IBM PC Compatibles running DOS
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11.1. OS/2
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12. Individual Modem Settings
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12.0. Setting up a kind of modem not described below
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12.1. Setting Up a US Robotics/Miracom Modem
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12.2. Apple Express Modem
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12.3. BT NS 2232 M
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12.4. Dowty
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12.5. Dynalink
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12.6. Gateway
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12.7. Global Village
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12.8. Mistral
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12.9. Multitech
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12.10. Pace Microlin
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12.11. Pace Mobifax
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12.12. Racal
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12.13. Rockwell chipset modems
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12.14. SmartOne
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12.15. Supra modems
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12.16. Yoriko modems
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12.17. Zoltrix
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12.18. Zoom modems
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12.19. Zyxel
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13. Testing
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14. Finally
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1. General
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============
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This document will point out some general essentials and advice on
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setting up your modem. A section at the end discusses specifics
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regarding a DOS setup running the KA9Q NET.EXE program. Due to the vast
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combinations of computer and modem setups it is impossible to give
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specific help for all types.
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Making an Internet (IP - Internet Protocol) connection via a modem is
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very different from a standard dial-up connection. Do not assume that
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just because you can download from a BBS (and maybe upload) or use other
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services that you have your communication (comms) set-up 100% sorted out.
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Due to the nature of IP, if you get errors, throughput can be hit very
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badly. Under IP information is sent in packets and for maximum speed
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these should generally be as large as possible up to a maximum of about
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1500 characters. If a packet gets messed up (garbled) its entire
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contents will have to be resent - hence a large speed degradation may
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occur.
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One exception to this is when an interactive sessions are sharing a
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TCP/IP link with more voluminous transfers such as NNTP or SMTP. In this
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case it can be preferable to have smaller transmission units (Maximum
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Transmission Units setting or MTU) so that keystrokes/screen updates will
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fit into the data stream with less delay. If a large MTU is used this
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can lead to what feels like a jerky or intermittent session.
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Enough of the technical parts, there follows some sound advice that
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everybody should take note of.
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2. Essentials
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===============
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Correct modem settings:
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Full hardware handshaking (CTS/RTS),
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Flow control
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XON/XOFF (software handshaking) set to off
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Settings must be bi-directional where appropriate.
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A full specification modem cable (open yours up - if it has
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only 3 wires it is no good).
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A serial chip that can cope with the high speeds (if using a
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high speed modem). Extended memory drivers and Terminate Stay
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Residents (TSRs) etc. can interfere with the handling of
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interrupts from serial chips.
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3. Telephone Exchange
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=======================
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The Demon Internet Service (DIS) is on modern digital exchanges
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so you should have little trouble with ringing tones etc when
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connecting to us. If you are on an older exchange, your modem
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may not recognise the dialling tone. If this happens, look in
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your manual and change the setting that overrides the dial tone
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recognition.
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Note that when you make changes to a modem's settings you
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should always reset the modem first, make the change and then
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save the settings. You will need a comms or "terminal
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emulation" package such as Telix, Procomm, Window's Terminal, Z-
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Term, Microphone etc. Look in your modem manual for
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instructions. Mostly you will be able to type ATZ <return> to
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reset your modem. On a US Robotics/Miracom modem you could
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type:
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ATZ Reset the modem
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ATX3 Alter a setting
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AT&W Write the settings to Non-Volatile RAM (NVRAM)
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The last bit (AT&W) is useful as it means that when the modem
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is reset, it will remember the settings you have stored.
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If going through a private telephone network (or PABX) first,
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you will probably need to dial a number such as 9 to get an
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outside line. Make sure your dial string has this in. You may
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need to separate this from the number to dial by a separator
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such as a comma so that there is a pause to give your telephone
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system time to give you an outside line:
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9,01813434848
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4. Internal Modems
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====================
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Internal modems have the advantage of not having a serial lead
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to worry about but the disadvantage of using an extra interrupt
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and generally don't have any lights to let you know what is
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going on. Ensure that the interrupt on which the modem sits
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does not interfere with any others - refer to the setup program
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for your computer and your modem manual. This may require
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altering a jumper (a small connector) on the main computer
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board (mother board) on your computer or on a separate board.
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This should be well documented and is well within the scope of
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the average user. Ensure that the modem is seated correctly in
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the expansion slot.
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5. Which Phone Number
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=======================
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We have multiple Points of Presence (PoPs) - please see
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/pub/doc/Demon.txt for details. Thus you will have a choice of
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numbers to ring. You may use any of our PoPs at any time.
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6. Modem and Telephone Leads
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==============================
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Your modem lead should be in good condition and preferably not
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wrapped in a tight circle or running parallel to high power
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cables etc. This will normally only affect longer runs and, as
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your cable should be earthed, will not often be a problem. The
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cable should be connected securely at both ends as should the
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telephone cable. If you suspect your telephone socket may be
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causing a problem then test it with a standard plug in
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telephone. Use the correct type of modem lead - they vary from
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country to country.
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7. Serial Chips
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=================
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The type of serial chip (Universal Asynchronous
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Receiver/Transmitter - UART) in use can make a big difference
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to comms performance/reliability. At higher speed the computer
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can sometimes not service the serial chip fast enough to catch
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all of the characters arriving down the line. This problem
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increases if running under a multi-tasker such as Windows,
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certain memory managers and other TSRs.
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8. Speed
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==========
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Close to every modem user's heart is the speed at which they
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can operate. There are two different speeds: the first is the
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speed at which a modem can talk to another modem; the second is
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the speed at which the modem can talk to its controlling
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computer (the DTE rate).
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Firstly, we will discuss the connect rate. A V.22bis modem can
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connect at a speed of 2,400 bits per second. There are 8 bits
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in a byte (a byte is usually one character) so that is a
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maximum of 300 characters per second (cps). Due to start and
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stop bits, each byte will take 10 bits reducing the speed to
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240 characters per second. When running over IP there is a
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slight overhead and so you will never see this maximum.
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However, as you can (and will) have several things happening at
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once, you will be able to make very good use of your available
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bandwidth.
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Many modems have compression protocols built in to them. MNP/4
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and V42 use synchronous connections to provide an error free
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connection between modems, saving the start and stop bits.
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This gives at least a 20% increase in throughput. V42bis adds
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compression, provided that the DTE rate is higher than the
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connection rate. This means that when downloading a plain text
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(or ASCII) file, it is possible to get faster speeds by
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compressing the data. The data is compressed so that the same
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information can be encoded in to a smaller space. The
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receiving modem will of course unscramble the data for you. If
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news normally flows in at say 200 cps, then, on a 2400 cps
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link, you have up to 44 cps left at the same time for mail,
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telnet'ing, ftp'ing etc. Compression techniques do not work as
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effectively on binary files and make very little difference to
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pre compressed files (such as .zip, .zoo, .lha etc.).
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Note that MNP5 will usually degrade throughput on an IP link
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due to the packet based nature of it's compression method.
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V42bis does not suffer this problem as it is capable of
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optimising itself dependent on the type of data being
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transferred.
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Now we will discuss the second speed - the speed at which the
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modem and computer communicate with each other. This is called
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the Data Terminal Equipment (DTE) rate. If you have a slow
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modem, e.g. a 2400 baud one without MNP or V42, then it will
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probably only work correctly when talked to by the computer at
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the same speed. For the facts on your particular modem and
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computer you should refer to your manuals. On faster modems
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you will only be able to take advantage of some of the
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compression features by making the computer talk to the modem
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at a faster speed than modem is talking to the remote modem
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down the telephone line. Thus you should talk to a 9600 modem
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at 19200 or even 38400. You should check the maximum speed at
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which the serial port on your modem can talk and then set your
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communication package to work at the highest mutually available
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speed. Don't forget that without a buffered UART you are
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unlikely to sustain reliable high speed comms above 9600 baud.
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Please note that we only support modems capable of V22bis
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(2400) and upwards. If you have a US Robotics/Miracom HST
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modem, you may not get very good throughput in HST mode. In
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practice HST mode is fine if FTP'ing from a site without
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anything else happening (sending mail etc.) as it works fine in
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one direction at a time only.
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9. Trouble Shooting
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======================
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If you are getting garbled characters on the screen then
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something is wrong! Garbled characters are often a sign of
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mismatched speeds, lack of handshaking or a non-locked DTE
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rate. If you get as far as the login prompt but no further
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then make sure that your dialler script is working on 8 bit
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standard comms: 8 bits, no parity, 1 stop bit. See
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/pub/doc/Demon.txt for the full logon script details.
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Having checked your setup according to the information above,
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try reducing the speed at which the computer talks to the modem
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(if using a high speed modem) until the connection works. If
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you have to do this then either you are attempting to drive
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your computer or your modem at too high a speed, or you have
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other processes running which interfere with the correct
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running of your serial communications (as per Serial Chips
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above).
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If you have finished your live session and log off you may
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sometimes find that your phone line is not dropped. This can
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result in an unwelcome phone bill! There are a number of
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computer/software specific solutions to this problem and some
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answers are given in /pub/doc/Support.faq which may have been
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included in your installation. One thing to check on your
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modem is that the setting that makes the phone line drop when
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the computer tells the modem that it has finished, is on. The
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computer uses the serial port and drops DTR (Data Terminal
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Ready) and the modem spots this and hangs up the line. The
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setting often &D2 and you should read the section below which
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tells you how to set this. It is definitely &D2 for US
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Robotics, SupraFax and Dowty Quattro modems.
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If your modem sometimes seems to fail to recognise a ringing
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tone, reporting it as BUSY. This can be cured by adding a
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comma after the dial number, e.g. "ATDT0813434848,". This
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makes the modem pause and ignore the first rings which it
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sometimes things is a busy single. Some US Robotics modems can
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exhibit this problem.
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ATZ is the command that resets the modem. Setting your
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initialisation string to ATZA0 etc where A0 is the
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initialisation string is very likely to fail. This is because
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the modem takes a while to reset and throws away the data being
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sent to it in the meantime. Some people beg to differ on this
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point. However it is certainly true on US Robotics modems.
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Just to confuse matters further there are often some switches
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on the modem which you can use to make further settings or to
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default to different options. These are referred to as DIP
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switches. Mostly, the advice contained in this document,
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refers to modems that have not had their switches tampered
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with. If you have the manual for your modem (and I hope you
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have!) then that will probably tell you what the default
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factory switch settings were. Make a careful note of the
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current settings and then change back to the factory defaults.
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If you already use your modem with other packages, make sure
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they still work. These DIP switches must be set to ensure that
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the reset command ATZ resets the modem to the stored values.
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On some modems it is possible to make ATZ restore to factory
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settings which rather defeats the object of configuring it!
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Some modems have ATY commands instead of DIP switches and so it
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is important that the correct ATY command has been used.
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Fortunately, the default will ok if no ATY command has been
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issued.
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If you are getting a no response from the modem before dialling
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(eg. The dialler in KA9Q reporting "INPUT LINE WAIT 3000 OK")
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then that means that either your modem is not connected
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properly (check the cables, or for internal modems, check
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jumper settings, and check software configuration to check that
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the dialer is trying to talk to the modem on the correct port),
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or your modem is not configured for verbal result codes.
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Normally the command to accomplish this is ATV1 .
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There is a section below which specifically refers to problems
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that may be encountered by PC users.
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10. Software and Other Factors
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===============================
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By configuring your software correctly you can make significant
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improvements to an under performing communications connection.
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Things to check for include badly fragmented disks (run a disk
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de-fragmenter such as Norton's Speed Disk), no disk cache, no
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or insufficient buffering inside the software and unnecessary
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checking protocols or indexing taking place. Refer to your
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software's instructions for details on these.
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11. Help for Specific Computers
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================================
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Some extra comments for some operating systems which may be of use
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follows.
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11.0. IBM PC Compatibles running DOS
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========================================
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In addition to the above info there is some specific advice
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below for those of you running DOS.
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Some modems send back "OK" when sent ATZ (the reset command)
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even though they are not ready. This means that the dialer
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program will try to ring out even though the modem is not
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ready. The effect is that you will see ATZ on the screen
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followed by OK and then the program will not dial. Eventually
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it will time out. To avoid this, send AT instead of ATZ in the
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modem initialisation string.
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Extended memory drivers can interfere with the correct
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operation of your serial communications. If you suspect this,
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rename your CONFIG.SYS and AUTOEXEC.BAT files and then reboot
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your computer to see if the connection improves.
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If you have a V.32bis 14,400 modem you will probably want to
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talk to it at 38,400. Unless you have a suitable serial chip
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then you will get errors and, as explained at the start of this
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document, this can seriously impact the throughput. When
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running NET.EXE you can type asystat at the net> prompt and
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information about your serial comms will be printed to the
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screen. The interesting parameter is the third one on the
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second line, 'hw over'. This shows how many hardware overruns
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(characters lost because they weren't fetched from the serial
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chip in time) have occurred. These overruns are usually due to
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lack of either a buffered UART or hardware handshaking.
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As already stated, for maximum performance you will need to
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have a buffered chip. For this you will need a 16550A - this
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is the number that is written on the chip. The asystat command
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will tell you if a 16550 is detected. Unfortunately, even top
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manufacturers overlook this area so it is quite likely that
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your chip is below par.
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If in doubt, open up your computer and locate the serial chip.
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If it is not a 16550 then it might need replacing. If you are
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handy with a soldering iron you could replace it, but this is
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not advisable unless you are really confident. If the chip is
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socketed then it can be removed and a 16550 (costing about #16
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- we sell them) be put in its place. If not then you could buy
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an extra serial card with a 16550 already on it costing from
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around #30 to #70 depending on the specification.
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Some internal modems use a 16450 with a large buffer (1K) and
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this may be enough to stop hardware overruns.
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If you are using a standard serial port then the settings
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offered for COM1, 2, 3 or 4 in the configuration program in
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DIS.EXE will probably be fine. Otherwise you should refer to
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your manuals and enter the appropriate IRQ number and I/O base
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address.
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If you install an extra serial card then be aware that if you
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have, for example, a mouse on COM1 then you should not use COM3
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for your modem using the default IRQ setting as they share the
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same interrupt.
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There is another factor that can impede throughput and that is
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software overruns. Using the NET.EXE software, at the net>
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prompt having just received some news or ftp'd a file, type
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asystat and look at the figure before sw over. If this is not
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0 then you are getting software overruns. To fix this,
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increase the buffer size in the attach line near the top of
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autoexec.net:
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attach asy 0x3f8 4 ppp sl0 4096 1500 38400
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Alter the 4096 in the above to be 8192, 12288 or higher until
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the software overruns are cured.
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More information on tuning is available in
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/pub/doc/ka9q/Tuning.faq.
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11.1. OS/2
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==============
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If intending to run the DIS DOS software in an OS/2 2.x DOS
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session you should get a copy of sio126c.exe and install the
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communications driver in it before running DIS. sio126c.zip is
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available on our ftp server or via our guest download account.
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This is because the standard communications drivers do not pass
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to DOS the buffering of your 16550A buffered serial chip.
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12. Individual Modem Settings
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==============================
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12.0. Setting up a kind of modem not described below
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========================================================
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To change the settings of your modem, use a program that can
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talk directly to the modem, such as a standard communications
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package.
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(*) In Windows, you can use Terminal (in the Accessories
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Group), setting it for the correct connector (COM Port).
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(*) On the Macintosh, you can use ConfigPPP by switching
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Terminal Window on, and clicking Open. When you are finished,
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switch off Terminal Window again.
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Type the reset command, usually ATZ <RETURN>, and see the
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response OK. Then continue through the list of settings. You
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can type ATI4 <RETURN> or AT&V <RETURN> to see what your
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current settings are on a lot of modems. For connecting to
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Demon we recommend the following:
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Use V.32bis modulation/CCITT protocols rather than HST
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Originator mode
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Local echo ON
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Duplex OFF; receiving system sends duplicate data
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All result codes displayed
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Display result codes in verbal (not numerical) mode, e.g. OK
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not 0
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Enable additional error control indicator, e.g. LAPM/V42BIS
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Serial port remains at fixed setting
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Modem send CD (Carrier Detect) on connection
|
|
Terminal sends DTR (Data Terminal Ready)
|
|
Data Set Ready (DSR) controlled by the computer
|
|
Hardware CTS (Clear to Send) transmit data flow control
|
|
Received Data h/ware (RTS) flow controlled by computer
|
|
Received Data software flow control disabled (make sure the
|
|
modem uses hardware flow control, and switch off
|
|
XON/XOFF flow control, also known as software flow
|
|
control)
|
|
MNP 5 data compression disabled
|
|
Variable link speed negotiation
|
|
1800Hz UK guard tone on. (Probably AT&G2)
|
|
|
|
When done, type the command that saves the settings to Non
|
|
Volatile Ram (NVRAM) (usually AT&W) so that they areremembered
|
|
when the modem is reset.
|
|
|
|
|
|
12.1. Setting Up a US Robotics/Miracom Modem
|
|
================================================
|
|
|
|
To set up your modem, use a standard communications package.
|
|
Type ATZ <RETURN> and see the response OK. Then continue to
|
|
make the settings. You can type ati4 <RETURN> and ati5 to see
|
|
what your current settings are. For connecting to Demon we
|
|
recommend the following:
|
|
|
|
B0 V.32bis modulation rather than HST
|
|
C1 Transmitter enabled
|
|
E1 Local echo ON
|
|
F1 Duplex OFF receiving system sends duplicate data
|
|
Q0 Result codes displayed
|
|
V1 Display result codes in verbal (not numerical) mode
|
|
&A3 Enable additional error control indicator
|
|
&B1 Serial port remains at fixed setting
|
|
&C1 Modem send CD (Carrier Detect) on connection
|
|
&D2 Terminal sends DTR (Data Terminal Ready)
|
|
&G2 1800Hz Guard Tone
|
|
&H1 Hardware CTS (Clear to Send) transmit data flow control
|
|
&I0 Received Data software flow control disabled
|
|
&K3 MNP 5 data compression disabled
|
|
&N0 Variable link speed negotiation
|
|
&R2 Received Data h/ware (RTS) flow controlled by computer
|
|
&S1 Data Set Ready (DSR) controlled by the computer
|
|
|
|
e.g. type AT&K3 <RETURN>. When done type AT&W <RETURN> to save
|
|
the settings to Non Volatile Ram (NVRAM) so that they are
|
|
remembered when the modem is reset.
|
|
|
|
Some US Robotics occasionally mistake a System X (and Y?)
|
|
ringing tone for a busy tone and hang up just as the Demon end
|
|
answers. Sticking a pause on the end of the dialling sequence
|
|
stops the modem's response long enough for the Demon end to
|
|
start its negotiating sequence. This means that the confusing
|
|
System X tone is ignored. If the Demon end is busy you just to
|
|
wait a bit longer for the BUSY string, but not as long as the
|
|
setting in S7. Add a pause by adding a comma to the end of the
|
|
string.
|
|
|
|
|
|
12.2. Apple Express Modem
|
|
=============================
|
|
Just AT&F then AT&C0 to disable compression
|
|
|
|
|
|
12.3. BT NS 2232 M
|
|
======================
|
|
|
|
(Note this doesn't work reliably with dial, but does work with
|
|
TIP or with an outboard Kermit script.)
|
|
|
|
at &f0 s0=0 x7 m2 &u1 &k0 b0 s30=26 &e5 &r1 &d2 &c1 l3
|
|
&f0 - reset to factory default
|
|
s0=0 - suppress auto answer
|
|
x7 - maximum message generation (for diagnostic purposes)
|
|
m2 - speaker always on, so you can hear retrains
|
|
&u1 - RTS flow control
|
|
&k0 - CTS flow control
|
|
b0 - CCITT mode
|
|
s30=26 - CTS follows DCD **, plus defaults
|
|
&e5 - V.42bis (and LAPM)
|
|
&r1 - RTS locked on (??)
|
|
&d2 - DTR is Data Terminal Ready
|
|
&c1 - CD Normal
|
|
l3 - Speaker loud
|
|
|
|
** the theory is that it would otherwise try to track RTS when
|
|
that is used for flow control.
|
|
|
|
|
|
|
|
12.4. Dowty
|
|
===============
|
|
Dowty Quantum 144
|
|
|
|
To configure this modem for CTS/RTS only (hardware
|
|
handshaking):
|
|
|
|
&k2 Use CTS on transmission
|
|
&u2 USE RTS on receive
|
|
|
|
|
|
|
|
12.5. Dynalink
|
|
==================
|
|
Dynalink 1414VE: AT&Q9W1S37=11S48=0M0
|
|
|
|
&Q9 The modem will attempt V.42bis, fallback to V.42(LAP-
|
|
M), then fallback to normal mode.
|
|
W1 Reports the error correction protocol and the carrier
|
|
speed used.
|
|
S37=11 Sets DCE speed (modem to modem) to 14400bps.
|
|
S48=0 Disables protocol negotiation. Forces LAPM.
|
|
M0 Turns off the speaker. (This thing is loud!).
|
|
|
|
ATZ or AT&F as the first command as both of these seem to annoy
|
|
the modem into false starts.
|
|
|
|
ACTIVE PROFILE:
|
|
B1 E1 L0 M0 N1 Q0 T V1 W0 X4 Y0 &C1 &D1 &G0 &J0 &K3 &Q9 &R0 &S1
|
|
&T4 &X0 &Y0
|
|
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:050
|
|
S08:002
|
|
S09:006 S10:014 S11:095 S12:050 S18:000 S25:005 S26:001 S36:007
|
|
S37:011
|
|
S38:020 S44:003 S46:138 S48:000 S49:008 S50:255
|
|
|
|
|
|
|
|
12.6. Gateway
|
|
=================
|
|
|
|
Gateway Telepath modem: AT&K3s48=0s46=138s36=1
|
|
|
|
The modem works fine at 38400 and most of the time is OK with
|
|
14400 carrier. On occasion it works better by setting it down
|
|
to 9600 with n0s37=9 added to the init string.
|
|
|
|
|
|
|
|
12.7. Global Village
|
|
========================
|
|
From a user:
|
|
The specs for AT commands for a Global Village PowerPort Silver and Gold
|
|
modems are as follows:
|
|
AT {code} command... action...
|
|
\N5 (Set Operating Mode) Set auto-reliable(V.42 LAPM only)
|
|
\Q3 (Set Serial Port Flow Control) Enable bidirectionable hardware
|
|
flow control
|
|
\J0 (BPS Rate Adjust) Disable port rate adjust;
|
|
serial port rate independent of
|
|
the connection
|
|
%C1 (Data Compression) Enable data compression
|
|
(V.42bis in LAPM)
|
|
<these following could be helpful...>
|
|
&W1 (Store Active Profile) Save active configuration as User
|
|
Profile 1
|
|
&Y1 (Select Stored Profile On Power Up) Recall User Profile 1 on power up
|
|
&V1 (View Active Configuration and Stored Profile) View profile 1
|
|
|
|
|
|
12.8. Mistral
|
|
=================
|
|
|
|
For an Amber Logic Mistral FX144 modem.
|
|
Use the factory defaults and the following:
|
|
&E4 Forces the modem to reject the connection with
|
|
the
|
|
'NO CARRIER' message if it cannot establish a
|
|
V42 link
|
|
S31=2 Locks the DTE baud rate to 38400
|
|
|
|
|
|
|
|
12.9. Multitech
|
|
===================
|
|
|
|
AT&F
|
|
This just resets to factory settings.
|
|
|
|
From one of our users with a Multitech MT1932ZDXK V32Ter and
|
|
fax modem:
|
|
|
|
AT&F&E2&E7$MB14400X4M0S0=0
|
|
|
|
The X4 just gives you full result codes - not essential unless
|
|
you want to
|
|
know exactly what kind of connection you've got.
|
|
|
|
From a Multitech dealer:
|
|
|
|
&E4 Hard CTS/RTS
|
|
&BA0 Baud rate altering off
|
|
&E2 V.42 with no fall back to MNP5
|
|
&E15 Compression on
|
|
&D2 Hang up the line when DTR is dropped
|
|
|
|
|
|
12.10. Pace Microlin
|
|
=======================
|
|
|
|
AT &K3B0E1F0Q0V1%C2&C1&D2\N3
|
|
|
|
&K3 - RTS/CTS Handshaking
|
|
B0 - CCITT protocols
|
|
E1 - Enable Echo
|
|
F0 - Negotiate connect speed - may want to use F10 <14.4> if
|
|
saving for use with demon only.
|
|
Q0 - Enable result codes
|
|
V1 - Verbose result codes
|
|
%C2 - V42 but no MNP5 compression
|
|
&C1 - DCD follows carrier
|
|
&D2 - hang up on DTR
|
|
\N3 - Autoreliable link - use \N2 to reject links negotiated
|
|
without error correction.
|
|
|
|
AT &W to save as default, or AT &W1 to save in second NVRAM
|
|
section for recall with ATZ1 as modem initialisation string.
|
|
|
|
12.11. Pace Mobifax
|
|
======================
|
|
For connecting to Demon we recommend the following:
|
|
|
|
Command What it does
|
|
B0 Use V.32bis modulation/CCITT protocols rather than
|
|
HST
|
|
&C1 Modem send CD (Carrier Detect) on connection
|
|
E1 Local echo ON
|
|
F0 Variable modem-to-modem speed negotiation
|
|
Q0 All result codes displayed
|
|
V1 Display result codes in verbal (not numerical) mode,
|
|
e.g. OK not 0
|
|
X4 Gives full CONNECT string
|
|
&D2 Terminal sends DTR (Data Terminal Ready)
|
|
&S1 Data Set Ready (DSR) controlled by the computer
|
|
&K3 RTS/CTS flow-control
|
|
|
|
When done, type the command that saves the settings, AT&W, so
|
|
that they are remembered when the modem is reset.
|
|
|
|
|
|
12.12. Racal
|
|
===============
|
|
From a user:
|
|
My modem is a model Racal Maxam V 9600 baud, about 2 years
|
|
old.I have been told that a Racal connected to a US Robotics
|
|
the Racal can detect a higher baud carrier as its own 9600
|
|
carrier.When connected you will get lots of 8bit characters
|
|
and the modem will then drop the line.This can be solved by
|
|
forcing the modem to 9600 and not checking for errors at this
|
|
baud rate.
|
|
|
|
The command string is atn0f8&e0&w0 for a Racal:
|
|
n0 - Do not seek the baud rate
|
|
f8 - Force baud to 9600
|
|
&e0 - No error check
|
|
&w0 - Write change
|
|
|
|
|
|
12.13. Rockwell chipset modems
|
|
=================================
|
|
|
|
Rockwell chipsets are used in a variety of modems, namely Supra
|
|
and SmartOne.
|
|
B0 v32bis modulation
|
|
E1 Local echo on
|
|
V1 Word response for errors
|
|
Q0 Modem sends responses
|
|
F1 Duplex off. (Can't find any not to)
|
|
&A3
|
|
&S1
|
|
|
|
There is an "undocumented" feature present in the Supra
|
|
V.32/V.32bis FAX Modems that can help improve the quality of
|
|
FAX and Data transmissions.
|
|
|
|
The AT\E1 command is not documented in Supra's manuals, but is
|
|
present in the Rockwell V.32/V.32bis firmware/chipsets on which
|
|
the Supra V.32/V.32bis FAX Modems are based. This command is
|
|
documented in the RC96AC and RC144AC Modem Designer's Guide
|
|
from Rockwell International.
|
|
|
|
|
|
|
|
12.14. SmartOne
|
|
==================
|
|
(also badged Best Data, CalCom)
|
|
&F Restore factory settings
|
|
B0 Select CCITT V.22 and V.21 mode
|
|
C1 Normal transmit carrier switching
|
|
E1 Command character echo enabled
|
|
F1 On-line state character echo disabled
|
|
Q0 Result code messages sent to machine
|
|
V1 Result code messages sent in English word format
|
|
&C1 DCD indicates on-line data carrier detected
|
|
&D2 Modem disconnects when DTR drops
|
|
&G2 1800 Hz Guard Tone
|
|
&K3 Enable CTS/RTS flow control
|
|
&Q6 Select Asynchronous operation in normal mode
|
|
&R0 CTS follows RTS
|
|
&S1 DSR turned off while carrier is lost
|
|
\G0 Disable Xon/Xoff flow control
|
|
|
|
For v32bis (14,400 baud) models:
|
|
|
|
S37=11 Attempt to connect at 14400 bps
|
|
|
|
|
|
12.15. Supra modems
|
|
======================
|
|
|
|
Supra 14.4k fax modems need the ROM revision 1.70B or later but
|
|
their ROM revision number is odd. Revision 1.8 or 1.4 are also
|
|
apparently OK.
|
|
|
|
Information providing features
|
|
Enable all CONNECT, PROTOCOL & COMPRESSION mesgs: s95=41
|
|
loudspeaker control (low volume, on until carrier): l1m1
|
|
|
|
Modem/PC signals
|
|
modems disconnects when DTR drops: &d2
|
|
DCD follows line carrier: &c1
|
|
Enable hardware flow control: &k3
|
|
|
|
Speed connection, reject bad lines
|
|
new models, only make LAPM Reliable connections: \n4
|
|
old models, make AutoReliable connections: \n3
|
|
Disable negotiation, make V42 (LAPM) connection: s48=0
|
|
connect at highest shared data rate: n1
|
|
|
|
Compression
|
|
new models, V.42bis (BTLZ) Enabled, (but not MNP): %C2
|
|
old models, enable data compression (BTLZ or MNP): s41=1
|
|
|
|
An initialisation string for this would be:
|
|
|
|
ats95=41 l1m1&d2&c1&k3 \\n4 s48=0 n1 %C2
|
|
^note the double '\' is needed if typing this
|
|
into some dialer programs
|
|
|
|
To put this into the modem's memory (NVRAM) type at&w
|
|
|
|
|
|
|
|
|
|
12.16. Yoriko modems
|
|
=======================
|
|
|
|
Yorikos work OK with a simple AT&F&C1&D2 set-up.
|
|
|
|
|
|
|
|
12.17. Zoltrix
|
|
=================
|
|
|
|
These are one of our user's settings for a Zoltrix v32bis
|
|
internal fax/modem. He writes:
|
|
|
|
With X4, W1 and V1, I've managed to configure it very nicely to
|
|
redial if the line's are busy after only 5 seconds, report
|
|
CONNECT, PROTOCOL CARRIER, and BUSY
|
|
|
|
The only bit I'm vaguely unsure about is, whether disabling
|
|
compression (%c0 on mine), disables v42bis also, as I really
|
|
only want to knock out MNP 5. &Q9 I think attempts v42bis,
|
|
falls back to LAP-M+v42, then to normal.
|
|
|
|
An annoying feature is that at&v only digs out probably a
|
|
quarter of the settings - the '\' and '%' commands don't
|
|
feature; some of them appear extremely useful: %Q for instance
|
|
purportedly reports line signal quality, and %L received signal
|
|
level, which I reckon might be relevant to one recent spate of
|
|
postings, and you can tune up v42bis with others.
|
|
|
|
S86 stores a connection failure cause code.
|
|
|
|
OK
|
|
at&v
|
|
ACTIVE PROFILE:
|
|
B0 E1 L0 M0 N1 Q0 T V1 W1 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q9 &R0 &S1
|
|
&T4 &X0 &Y0
|
|
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:060
|
|
S08:002 S09:006
|
|
S10:014 S11:095 S12:050 S18:000 S25:005 S26:001 S36:007 S37:000
|
|
S38:020 S44:003
|
|
S46:138 S48:007 S49:008 S50:255
|
|
|
|
Another user writes:
|
|
|
|
Rom revision (use ATI0 or similar to check) : See below
|
|
|
|
AT&Q5S48=7S46=138S95=46
|
|
|
|
Rom revision
|
|
------------
|
|
|
|
I have listed what comes out of ATI0 to ATI4 as ATI0
|
|
doesn't make sense!
|
|
|
|
ATI0 = 14400
|
|
ATI1 = 007
|
|
ATI2 = OK
|
|
ATI3 = V1.410-AP39
|
|
ATI4 = a007880284C6002F
|
|
bC60000000
|
|
r1005111151012004
|
|
r3000111170000000
|
|
|
|
|
|
Additional modem string info. (may be of some use)
|
|
|
|
&Q5 = set error correction mode
|
|
causes the modes to try v42bis, then MNP5, then normal
|
|
connection
|
|
S48=7 = enable V42 negotiation
|
|
S46=138 = error correction with compression
|
|
S95=46 = display extended result codes
|
|
so I can see that i've got error correction
|
|
and compression :-)
|
|
|
|
|
|
I also have a line
|
|
|
|
echo atz > com3:
|
|
|
|
in my demon.bat file to reset my modem as my fax software
|
|
leaves it in a bit of a state :-( Two 'init' lines don't seem
|
|
to work (not that I'm bothered!)
|
|
|
|
Yet another user writes:
|
|
|
|
This might be helpful if anyone calls using a Zoltrix 28800/
|
|
Internal / Fax.
|
|
|
|
Setup straight from box, using a comms package.
|
|
Using factory settings, AT&F,
|
|
then alter s7 to = 20 ATS7=20
|
|
then alter b1 to b0 ATB0
|
|
then alter &q6 to &q5 AT&Q5
|
|
optional ATL1 to ATL2 ATL2 - modem volume to hear connect.
|
|
|
|
and then write these to the stored profiles
|
|
|
|
AT&W0
|
|
AT&W1
|
|
|
|
Software used:
|
|
|
|
Windows 3.11 for workgroups
|
|
MS-Dos 6.22
|
|
|
|
DISWIN.EXE from Demon
|
|
DIS216C.EXE " "
|
|
|
|
Cybercom.drv - from ftp.qualcomm.com (can't rem exact loc)
|
|
to replace standard comm.drv, supports higher speed 57600+
|
|
rather than 19200
|
|
|
|
In windows system.ini under 386Enh
|
|
|
|
Com*fifo=1
|
|
|
|
|
|
12.18. Zoom modems
|
|
=====================
|
|
|
|
From one user comes this:
|
|
|
|
Zoom 14.4X FaxModem Settings
|
|
============================
|
|
|
|
These setting are in use to connect to demon both via KAQ9 and
|
|
trumpet winsock (SLIP). The settings enable 14400 bps with V42
|
|
error correction and V42bis data compression. In operation I
|
|
achieve 2600 cps when obtaining mainly text news. Whilst I am
|
|
sure the settings work I do not vouch for the accuracy of my
|
|
interpretation of what they mean!!
|
|
|
|
To reset modem to stored profile:-
|
|
ATZ - sets to profile 0
|
|
ATZ0 - sets to profile 0
|
|
ATZ1 - sets to profile 0
|
|
|
|
To store current profile:-
|
|
|
|
AT&W0 - store as profile 0
|
|
AT&W1 - store as profile 1
|
|
|
|
For brevity I have left out setting that have no functional
|
|
relevence.
|
|
|
|
|
|
Profile Command comments
|
|
E1 ATE1 Command characters echoed
|
|
N0 *ATN0 (zero) Disable auto-mode
|
|
detection; connection speed specified
|
|
by register S37
|
|
Q0 ATQ0 (zero) Enable response to computer (DTE)
|
|
X3 *ATX3 Monitors busy tones; sends
|
|
X2 messages
|
|
Y0 ATY0 (zero) Disable long space disconnect
|
|
&C0 AT&C0 (zero) Forces RLSD (DCD) on
|
|
&D0 AT&D0 (zero) Data terminal ready options
|
|
&G2 *AT&G2 Enable 1800Hz guard tone
|
|
&J0 *AT&J0 (zero)Disable adjusting DTE speed
|
|
&K3 AT&K3 Enable RTS/CTS flow
|
|
control. VITAL for slip connections
|
|
such as Trumpet winsock
|
|
&R1 AT&R1 CTS is always on in
|
|
synchronous or drops if required by
|
|
flow control in asynchronous
|
|
&S1* AT&S1 DSR active after answer
|
|
tone detected and inactive after
|
|
carrier loss.
|
|
&T4 AT&T4 Responds to remote modem
|
|
request for digital loopback.
|
|
|
|
Registers
|
|
Set using ATSn=v Sets register n to value v
|
|
|
|
S37 11 *
|
|
|
|
All lines with an * are for items than are altered fron the
|
|
factory default settings.
|
|
|
|
We would recommend &d2 otherwise your modem may not hang up the
|
|
line when you have finished your call.
|
|
|
|
From yet another user: The best I've got so far for the Zoom
|
|
14.4X is AT&F0W0&C1&D2%C2
|
|
|
|
&F0 (manufacturer's defaults, so we know where we are)
|
|
W0 (limit the messages coming from the modem)
|
|
(W1 gives lots of messages from the modem but causes problems
|
|
for some people)
|
|
&C1&D2 (for hardware flow control)
|
|
%C2 (enable V42 bis but not MNP5)
|
|
|
|
|
|
|
|
12.19. Zyxel
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|
===============
|
|
|
|
From one of our users again:
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|
|
|
The following "dial_cmd" is for a Zyxel U-1496E+ modem
|
|
|
|
"ATL2N1X7&G2*E1DT"
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|
L2 --- sets a low (but not inaudible) speaker volume
|
|
N1 --- sets a low (but not inaudible) ringing volume
|
|
X7 --- sets result code options so that the "connect" message
|
|
is, for example, "CONNECT 14400/Arq/V42b"
|
|
&G2 -- enables 1800 Hz guard tone
|
|
*E1 -- terminate call if error control negotiation fails, ie.
|
|
insist on error-control or end call
|
|
DT --- dial using DTMF tones
|
|
|
|
|
|
|
|
13. Testing
|
|
===========
|
|
|
|
To test out your setup you could try using ping. ping
|
|
gate.demon.co.uk whilst logged on directly to gate should
|
|
return a speed of about 270ms on a fast link down to 1000ms on
|
|
a slow link.
|
|
|
|
Try using ftp to ftp.demon.co.uk and downloading files from
|
|
/pub/test. There are files of varying contents that have also
|
|
been compressed in various ways. "empty" files are there so
|
|
that you can test the maximum throughput on blank data. "full"
|
|
files contain a thorough mix of characters and so little
|
|
compression by your modem will be possible. "regular" files are
|
|
a mixture - just like this document or a Usenet news message.
|
|
Each of these three have been compressed using popular methods
|
|
and so you can try working on the compressed files as well if
|
|
you like. Try uploading these files to
|
|
ftp.demon.co.uk:/incoming to test the link in that direction as
|
|
well.
|
|
|
|
Using a V.32bis modem, the maximum throughput you are likely to
|
|
get on a binary file is 1,600 cps. On an ASCII file the
|
|
maximum is about 2,800 cps.
|
|
|
|
|
|
|
|
14. Finally
|
|
============
|
|
|
|
Please try to sort out your setup by following the above
|
|
advice. If you are still stuck then telephone the support line
|
|
on 0181-371 1010 during support hours to see if further help
|
|
can be offered. Full support line details are available in
|
|
/pub/doc/Welcome.txt.
|