VI.9.f. QBlazer$599. QBlazer is the first portable V.32/V.42bis modem (2.3"x2.4"x2.4"). It works with a 9-volt battery for about two hours.VI.9.g. WorldBlazerThis is the latest and greatest Telebit modem. The WorldBlazer is a dual-mode modem that is equipped with Turbo PEP and V.32bis/V.42bis. If you already own a Telebit modem, you can purchase a WorldBlazer (for $549) through Telebit's Loyalty Pays Again program until June 30, 1992.Note that T1600, T2500, T3000, and the WorldBlazer all offer the following features:* Built-in support for UNIX UUCP, Xmodem, Ymodem, Kermit file transfer protocols * Two types of dial-access security: password security and call-back security * Remote management and diagnosticsVI.10.  U.S. Robotics ModemsU.S. Robotics has been extremely successful with its high-speed modems. Here are its current offerings:VI.10.a.        Courier HSTThis is the modem that made U.S. Robotics the king of PC-based BBS communities. Unless you are only going to communicate with other USR HST modems, it is probably not a good idea to purchase this unit. The street price for a Courier HST is $550-$600.VI.10.b.        Courier V.32bisIntroduced in 1990, this is a V.32bis/V.42bis modem. It does not support HST. The current street price for a Courier V.32bis is $530-$570.VI.10.c.        Courier HST Dual StandardThis unit is introduced in 1990. If you need to connect to HST modems and also want to be able to talk to other V.32/V.32bis modems, this is the modem to buy. Its current street price is around $800. The street price for a HST Dual Standard is $800. (Note that earlier HST Dual Standard modems only support V.32 and not V.32bis.) The HST Dual Standard is considered by many BBS users as the best modem money can buy. In March 1992, U.S. Robotics shipped a Courier Dual Standard with a 16800-bps HST mode.The only reservation I have about the Courier modems is their size. The external Courier modems are rather bulky: 8.3" wide, 12.65" deep, 1.57" tall. I would not want to carry one of these with me when I travel. Incidentally, the new Courier Dual Standard is substantially trimmer in size.VI.10.d.        Sportster 9600 V.42bisThis unit is introduced in 1991. The Sportster  9600 is an entry level V.32/V.42bis modem from U.S. Robotics. The list price is $645 for the external version. ($595 for the Internal version).VI.10.e.        WorldPort 9600 V.32The WorldPort 9600 is a portable pocket modem. Originally made by Touchbase Systems, the WorldPort 9600 is a V.32/MNP5 modem. It does not support V.42/V.42bis. The WorldPort 9600 works with a 9-volt battery. The list price is $699.V.11.   Zoom ModemsZoom Telephonics has been making Hayes-compatible modems for quite some times now. I have used many Zoom modems in the past and they have proven to be reliable and inexpensive.VI.11.a.        V.32 TurboZoom has been making Hayes-compatible modems for a long time. The V.32 Turbo is their entry into the high-speed modem arena. The V.32 Turbo is a V.32/V.42bis with a 12000 bps turbo mode which is compatible with a V.32bis modem at 12000 bps. Zoom also makes an internal version of the V.32 Turbo that features a 16550 UART. PC Connection sells the the internal model for $329.VI.11.b.        VFX V.32bis and VFP V.32bisVFX V.32bis is an external V.32bis/V.42bis modem (list price $449). The internal version is called VFP V.32bis ($399). Both come with MTEZ (which includes ExpressFax) for IBM PC. Zoom also offers a Macintosh version that comes with QuickLink II ($449). MacConnection is selling the VFX V.32bis for $299.The Zoom VFX V.32bis and VFP V.32bis support Group3/Class 2 fax.VI.12.  Things to comeAlmost every modem manufacturer makes at least one V.32/V.42bis modem and a V.32bis/V.42bis modem now. The price for V.32 and V.32bis modems will continue to drop. In the past few months, the price difference between V.32/V.42bis and V.32bis/V.42bis modems is diminishing.Many new modems introduced in the past few months also offer fax capability. You can expect modem manufacturers to include fax capability as a standard feature in their products if they haven't done so already.VII.    Buying a High-speed ModemV.32 and V.32bis modems are clearly the standards of high-speed modems today. You should buy a V.32 or a V.32bis modem unless1. Your application requires a high-speed modem with a proprietary modulation protocol. In this case, you should consider a dual-mode modem that support both the proprietary protocol and V.32 (or V.32bis).2. You cannot afford a V.32 modem.VII.1.  Should you pay extra for a V.32bis modem?A V.32bis modem costs substantially more than a V.32 modem just a few months ago. However, the price difference bewteen a V.32bis and a V.32 modem (from the same manufacturer) are diminishing. If you're thinking about buying a high-speed modem, you should probably look for a V.32bis modem.Assuming the remote system support V.32bis, a V.32bis modem will  pay for itself rather quickly if you are placing long distance calls to the remote system. However, if you are using some packet-switching networks to reach the remote system by calling a local number. A V.32bis modem will be wasted since none of the packet-switching networks currently support V.32bis. In fact, they are just starting to offer 9600 bps access service. Part III of "The Joy of Telecomputing" provides a comprehensive discussion of the issues involved.VII.2.  Should you buy a modem with a proprietary protocol?It is generally not a good idea to purchase a modem which only supports a proprietary modulation protocol. You should consider getting a modem that supports dual modulation protocols (USR Courier Dual Standard, Telebit WorldBlazer, Hayes Ultra) if (i) you have to connect to a modem that uses a proprietary modulation protocol, or (ii) you need to have better throughput than a V.32bis modem can offer.VII.3.  Should you buy a 2400-bps modem with V.42bis?If you are thinking of purchasing a 2400 bps modem with V.42bis data compression, think again.We have mentioned earlier that V.42bis and MNP5 are useless for downloading compressed files. There is one more reason why a 2400 bps with V.42bis is generally not useful when you are calling commercial online services or BBS.Online services and BBS usually have separate phone numbers for 2400-bps and high-speed modems. Most of them do not support V.42bis on their 2400-bps lines. Therefore, you won't be able to make a connection with V.42bis if you call their 2400-bps modem lines.Couldn't you call their 9600 bps lines? Well, not really. Commercial online services, as well as many bulletin board systems, typically do not allow you to call their high-speed modem lines with a 2400-bps modem. You won't be able to make a connection even if you try.VII.4.  Beware of the AdsCurrent V.32 modems typically support MNP 2-5 and V.42/V.42bis. However, there are still some earlier models of V.32 modems in the market which1. may not support any error control or data compression protocol (Hayes Smartmodem 9600).2. may support MNP 2-5 but not V.42/V.42bis.3. may support proprietary data compression protocol (Microcom MNP9).4. may support V.42 but not V.42bis (Prometheus).When a modem is said to offer a 38400 bps speed (or throughput), it may mean that1. it is a V.32 or V.32bis modem with V.42bis2. it is a V.32 modem with proprietary data compression protocol (some Microcom modems)3. it is a high-speed modem with proprietary modulation protocol and V.42bis (U.S. Robotics Courier HST)4. it is a high-speed modem with proprietary modulation protocol and proprietary data compression protocol (CompuCom Champ)An ad that says "USR modem, 38400 bps throughput, V.42bis" does not tell us anything except that the modem is made by U.S. Robotics. It could be any one of the three Courier modems. It could even be a Sportster 9600.When a modem is said to offer a 9600 bps speed (or throughput), it may mean several things:1. it is a V.32 modem2. it is a high-speed modem using proprietary modulation protocol (Hayes    V-series Smartmodem 9600, Telebit 1000, etc).3. it is a 2400 bps modem with V.42bis data compression.4. it is a 2400 bps modem with 9600 bps fax 5. it is a 2400 bps modem both V.42bis and fax.VIII.   Setting Up Software To Work With High-speed ModemsGetting a high-speed modem is only half the battle. You will need to get it to work with your communications program. Most communications programs still come with settings configured for standard 2400-bps modems.Since all 2400- bps modems are Hayes-compatible, it is relatively easy to set up the software. You simply install the software as if you had a Hayes modem. The software usually will work flawlessly. And you don't really have to worry about things like the initialization string.Getting a high-speed modem to work with your software is a different story. There is no longer a Hayes standard that everyone follows. Here are some of the reasons why you need to know how to configure your high-speed modem to work with your communications program.First, your high-speed modem may not be supported by your software.Secondly, even if your software supports your high-speed modem, the software may not be set up properly.Finally, even if your software is set up properly, the settings may not work all the times.VIII.1. The Proper Software SetupWhen we say that the software is set up properly, we mean that1. the modem is initialized properly by the communications software, and 2. the settings of your software match those of the modemWhat is the proper way to initialize a high-speed modem? In general, your modem needs to be initialized to:1. Enable V.42bis Data Compression2. Enable hardware flow control3. Handle the DTR and CD signals properly (by adding &C1&D2 to the modem    initialization string)We'll use the ATI 9600etc/e modem as an example for our discussions below. The initialization string described here is for the ATI modem only. Refer to your modem manual for the equivalent initialization string for your modem.The ATI modem is supported by two popular communications programs: Qmodem and HyperAccess 5. Qmodem initializes the modem and also configures itself to use hardware flow control. HyperAccess 5 also initializes the modem properly, however it does not configure itself to use hardware flow control.All modems come with default settings preconfigured from the factory. Many V.32 high-speed modems are preset to use V.42bis and hardware flow control when they are turned on. This optimal configuration enables the modem to automatically negotiate a connection with either another V.32 modem supporting V.42bis or  MNP protocols (or even a standard modem).Interestingly enough, not all high-speed modems are configured this way. The ATI 9600 etc/e modem, for example, is preset to use V.32 without error control or data compression at poweron. (Why? Good question.)As a result, your communications program needs to issue the appropriate initialization string (AT&F2) to set up the ATI modem to use V.32 with V.42bis and hardware flow control.There is another change required. And it has to do with the parameters controlling how the modem deals with two of the RS232 signals: DTR (Data Terminal Ready) and CD (Carrier Detect).CD is a signal generated by the modem which is used to indicate its connection status. DTR is a signal generated by your computer. DTR is used to enable the modem to accept commands from your communications program, it is also used by most modems to determine when to disconnect a call.The factory default setting for DTR tells the modem to ignore change in DTR (&D0), and the setting for CD forces CD always on (&C0). These specific settings are required by some dedicated dumb terminals in order to communicate with the modem. (Virtually all modems use &C0&D0 as the default setting.) However, these settings will often cause problems when hanging up the phone lines or produce an error message which says the modem is online when it is not.Most communications software programs expect the modem to follow DTR and expects CD to follow carrier. "&C1&D2" sets the parameters for the modem to handle the DTR and CD signals as expected by most communications programs. (However, if you use a Mac, you should use "&C1&D0".)Therefore, the proper initialization string to use for the ATI modem should be "AT&F2&C1&D2" if you have a PC, and "AT&F2&C1&D0" if you have a Macintosh.VIII.2. Does Your Software Initialize the Modem Properly?Let's take a look at the initialization stri