The World of Computer Software/The World of Computer Software.iso/sysmod20.zip/SCOUT.TXT

Text File | 1993-01-09 | 30KB | 731 lines

Newsgroups: comp.dcom.modems
From: [e-mail] (Wolfgang Henke)
Subject: Re: Need info/experiences with Digicom Scout and AT&T Dataport
Message-ID: <[e-mail]>
Organization: Netcom
References: <[e-mail]>
Date: Fri, 8 Jan 1993 17:22:20 GMT

Guillot, Burt J. ([e-mail]) wrote:
: I'm considering buying another modem.  I was considering a ZyXel, but their
: prices have just gone way too high.  So, I've seen the latest sysop deal
: prices on the AT&T Dataport and they seem reasonable.  So, has anyone
: tried this modem and how is it?  Also, how do people like their Digicoms?
: I hear there is a Wolfgang selling the external 14.4Ks with FAX here on
: Internet for a good price.  Was it $199 or $249, I can't remember?

Here is the Wolfgang. You can look for some Scout+ info in my ftp
directories either at ftp.rahul.net or ftp.netcom.com. Since several
users asked for the longer textfile, Scout.txt, here is the recently
updated version for you:


           Scout Plus V.32bis data and fax modem information file
           Wolfgang Henke, [e-mail], [e-mail]


                   1.     DATASHEET
                   2.     PHYSICAL DESCRIPTION
                   3.     SOFTWARE
                   4.     COMMAND SET
                   5.     TESTS
                   6.     BUGS
                   7.     USES
                   8.     TECH SUPPORT
                   9.     OTHER AND NEW DIGICOM PRODUCTS
                  10.     ORDER INFO


        1. DATASHEET (verbatim): The Digicom Systems Inc. Scout Modem Series

        Scout Plus: V.32bis with Group 3 Fax

          With up to 57,600 bps throughput, the Scout Series is the optimum
        choice for high-speed data communications. The full-featured Scout
        Plus V.32bis data/fax modems will make your PC a complete high-speed
        telecommunications tool.

        Features:
        * Full compliance to CCITT standards ensures worldwide compatibility
          with the broadest range of modems.
        * Scout modems integrate CCITT V.42bis and MNP 5 data compression to
          maximize data throughput up to 57,600 bps.
        * The Scout Plus combines V.32bis and Group 3 fax with Delrina's
          WinFax Lite and DosFax Lite sofware for WYSIWYG faxing.
        * All Scout modems include Qmodem data communications software.

          The Scout series incorporates an award-winning V.32bis modem design
        and offers all the necessary features for easy communications with
        computers, information services and Bulletin Board Services. It
        features V.42bis and MNP 5 data compression with error control and
        hardware flow control to keep your calls efficient. Compliance with
        CCITT international standards and our Adaptive Rate feature ensures
        compatibility to the broadest range of modems.

          The Scout Plus combines 14,400 bps V.32bis and Group 3 send and
        receive fax and is bundled with WinFax Lite 2.0 and DosFax Lite
        software for WYSIWYG faxing. It's ideal for any data or fax
        communications.

        Product Features

        CCITT V.32bis (14,400 bps)
        CCITT V.32 (9600 bps)
        CCITT V.22bis (2400 bps)
        CCITT V.22, Bell 212A (1200 bps)
        CCITT Group 3 send and receive fax
        CCITT V.29, V.27ter and V.21
        57,600 bps data throughput
        CCITT V.42bis and MNP 5 compression
        CCITT V.42 and MNP 2, 3 and 4 error correction
        High performance 16550 UART (internal models)
        Extended AT command set compatibility
        Auto line monitor and retrain
        Adaptive rate negotiation
        Automatic speed negotiation upon connection
        WinFax Lite and DosFax Lite software
        Qmodem data communications software

        Specifications

        Data Modulation Rates
        CCITT V.32bis, V.32, V.22bis, V.22 and Bell 212A

        Transmission Speeds
        14,400, 12,000, 9600, 7200, 4800, 2400, and 1200 bps

        Data Compression        CCITT V.42bis and MNP 5

        Error Correction        CCITT V.42 and MNP 2, 3 and 4 using LAPM

        Fax Specifications
        CCITT Group 3 compatible fax machines and fax modems
        CCITT V.29, V.27ter and V.21
        9600, 7200, 4800 and 2400 bps
        EIA-578 Class 1 compliant
        computer system must have at least 640k of memory (RAM),
        hard disk and DOS 3.3 or higher

        Flow Control            XON/XOFF, RTS/CTS

        Operation               Asynchronous full duplex dial-up

        Commands                Extended AT commands with non-volatile memory

        Test Modes              V.54 analog and digital, local and remote
                                loopback with self-test

        Compatibility           Internal: Any IBM PC, 286, 386, 486 or
                                compatible
                                External: Any computer with an RS-232 serial
                                port, (16550 UART recommended)

        Auto-dialing            10 numbers can be stored in non-volatile memory

        Environmental           Temperature: 0 to 50 degrees Celsius
                                Relative Humidity: 0 to 95 percent,
                                non-condensing

        Certification           FCC type B, DOC, UL and CSA certifications
                                in place or pending

        Warranty                5-year limited warranty

        Copyright 1992. Scout, Scout Plus are trademarks of Digicom Systems,
        Inc. Qmodem, WinFax Lite, DosFax Lite, MNP, IBM and other product
        names are trademarks of their respective companies. The above
        information is subject to change without notice.

        DSI, Digicom Systems, Inc.
        188 Topaz Street
        Milpitas, CA 95035


        2. PHYSICAL DESCRIPTION:

        The Scout Plus PC, the internal model is a 4 by 6 inches large
        rather compact halfcard. It has a 16550 16 byte buffer. The compact
        size makes this modem a good choice for portable computers, or
        other uses where space is at premium.

        Scout Plus, external model
        On the 5 1/2 by 1 1/2 front panel are 10 LEDS:

        MR      modem ready
        TR      terminal ready
        AA      auto answer
        EC      error correction
        HS      high speed
        RD      receive data
        SD      send data
        CD      carrier detect
        CS      clear to send (hardware flow control)
        OH      off hook

        The body of the modem is manufactured out of sturdy grey plastic
        with a 5 1/2 by 8 1/2 footprint. The top shows some venting grills.
        The back carries these connectors from left to right:

        RS-232 DB25 female
        Two switches for forcing DCD on and test mode
        RJ11    phone
        RJ11    line
        5 pin power connector
        ON/OFF SWITCH

        These power supplies are available:

        110 Volts, 60 Hz, 12 W input, 9V, 1 A output, US style three pronged
        integrated power supply-plug.

        185 to 240 Volts with US style three pronged plug

        185 to 240 Volts with German style two pronged plug

        The bottom panel carries a sticker with key AT Commands and the data
        compression/error control commands.

        The FCC sticker says: Complies with Part 68 Rules. FCC IDENTIFICATION:
        GSX-USA 65928-FA-E, Ringer equivalence: .8 B
        FCC Class B approval is pending

        The EPROM version is also printed on the bottom on a small label
        in the rear.

        Now we take it apart and find these chips:

        Analog Devices ADSP-2101 chipset (2105 family) running at 13.8
        MHz. Two ROMs with 1 Mbit and 512 kbit size. The first ROM stores
        the code for the digital signal processor (DSP) and the second
        for the separate microcontroller. The RS 232 drivers are
        14C88/14C89.

        The board looks clean with no glitches or wire add-ons
        detectable.  It was easy to reassemble with just four Phillips
        screws which are accessible from the bottom.


        3. SOFTWARE

        The Scouts come with Qmodem data communications software on a
        1.2 MB 5 1/4 floppy. The software is preregistered, which means
        prepaid and the owner merely has to send in the registration
        card provided to Mustang Software to get access to their
        technical support.

        The fax software is Delrina's WinFax Lite 2.0 and Delrina's
        DosFax Lite. Delrina's packages have been editors choice in a
        recent review of fax software in PC Magazine.

        The MacIntosh package is available now with the correct MacIntosh
        to modem cable which allows hardware handshake and Appletalk
        Remote Acess. The fax software is Smith's Microsoftware's
        QuickLink II/Fax.


        4. COMMAND SET:

        Standard Commands

        A       answer incoming call
        A/      Re-execute last command line
        AT      ATtention characters
        Dn      Dial telephone number n. You can also include:
                T-touch-tone dialing
                P-pulse dialing
                W-wait Register S7 time
                ,-pause Register S8 time
                @-wait for 5 seconds of silence
                ;-return to Command Mode after dialing
                !-go on-hook for 1/2 second
        DSn,    Dial stored telephone number
        E0      Command characters not echoed
        E1      Command characters are echoed
        +++     Escape from Data Mode to Command Mode
        H0      Disconnect and go on-hook
        H1      Force modem off-hook
        I0      Reply 960 or 961
        I1      Send software/firmware version to DTE
        I2      Send internal checksum to DTE
        I3      OK
        I4      CPU RAM content
        I5      Power-on test results
        I6      Last disconnect reason
        I7      AT commands summary
        I8      EE-ROM content
        K0      Prevent break during MNP
        K1      Allow break during MNP
        M0      Speaker is always off
        M1      Speaker on until carrier is detected
        M2      Speaker is always on
        O0      Return to data mode
        O1      Return to data mode and retrain
        Q0      Send responses to DTE
        Q1      Do not send responses to DTE
        Q2      Send responses only when originating call
        Sr?     Read and display Register r value
        Sr=n    Set register r to value n
        SQ      Monitor signal quality (real time)
        V0      Send responses in numbers
        V1      Send responses as words
        X0      Basic responses/blind dialing
        X1      Extended responses/blind dialing
        X2      Extended responses/dial tone detection
        X3      Extended responses/blind dialing and busy signal detection
        X4      Extended responses/dial tone and busy signal detection
        X5      Basic response/dial tone and busy signal detection
        Z       Load stored parameters into memory

        &- Ampersand Commands

        &B0     Force DSR signal ON
        &B1     DSR follows DTR signal
        &B2     DSR follows normal RS-232
        &C0     Force DCD signal ON
        &C1     DCD follows normal RS-232
        &C2     DCD forced on (CD wink)
        &D0     Force DTR signal ON
        &D1     Go to Command Mode after DTR loss
        &D2     Disconnect after DTR loss
        &D3     Disconnect and load stored parameters
        &F      Load factory command parameters
        &M0     Asynchronous communication
        &R0     CTS signal follows RTS signal
        &R1     CTS follows DCD signal
        &R2     Force CTS ON
        &S      Display stored telephone numbers
        &T0     End test in progress
        &T1     Start Local Analog Loopback test
        &T3     Start Local Digital Loopback test
        &T4     Grant remote request for Remote Digital Loopback test
        &T5     Deny remote request for Remote Digital Loopback test
        &T6     Start Remote Digital Loopback test
        &T7     Start Remote Digital Loopback test with self-test
        &T8     Start Local Analog Loopback Test with self-test
        &W      Permanently store current parameter settings
        &Zn:    Store telephone numbers in location n (1-10)


        *- Asterisk Commands

        *E0     No error control
        *E1     Auto reliable MNP 5
        *E2     Reliable MNP 5
        *E3     Auto reliable MNP 4
        *E4     Reliable MNP 4
        *E5     Auto reliable V.42 with phase detection
        *E6     Reliable V.42 with phase detection
        *E7     Auto reliable V.42 without phase detection
        *E8     Reliable V.42 without phase detection
        *E9     Auto reliable V.42bis with phase detection
        *E10    Reliable V.42bis with phase detection
        *F0     Disable flow control
        *F1     XON/XOFF passthrough
        *F2     XON/XOFF
        *F3     Hardware flow control (RTS/CTS)
        *G0     Adaptive handshake disabled
        *G1     Adaptive handshake enabled
        *M0     Send DTE-to-DCE connection speed responses
        *M1     Send error correction responses
        *M2     Send error correction responses and type
        *N0     Modem connect rate = 1200
        *N1     Modem connect rate = 2400
        *N2     Modem connect rate = 4800
        *N3     Modem connect rate = 9600
        *N4     Modem connect rate = 7200
        *N5     Modem connect rate = 12,000
        *N6     Modem connect rate = 14,400
        *O      Display parameter settings, also receive level when online
        *P0     Enable user abort feature
        *P1     Disable user abort feature
        *Q0     Turn off signal quality action
        *Q1     Signal quality action, allow retrain at same speed
        *Q2     Signal quality action, allow fallback and fallforward
        *Q3     Signal quality action, allow disconnect if no data throughput
        *S0     Turn off speed conversion
        *S1     Turn on speed conversion
        *T0     Turn off Trellis coding
        *T1     Turn on Trellis coding


        S-Registers

        S0      Rings to auto-answer calls
        S1      Count no. of incoming rings
        S2      Escape characters
        S3      Carriage return character
        S4      Line feed character
        S5      Backspace character
        S6      Dial tone wait time
        S7      Remote carrier wait period
        S8      Comma pause time
        S9      Carrier detect response time (double for international calls)
        S10     On-hook delay period
        S12     Escape guard time (disabled)
        S13     Reserved for tech support options
        S15     V.42bis/MNP abort
        S17     CNG tone
        S18     Duration of modem tests
        S25     DTR delay
        S26     Request to CTS delay

        +F Fax Commands

        +FCLASS=?   Interrogate fax, data mode
        +FCLASS=0   Set to data mode
        +FCLASS=1   Set to fax mode
        +FCERROR    Error response
        +FTM=<mod>  Send data
        +FRM=<mod>  Receive data
        +FTH=<mod>  Send data with HDLC framing
        +FRH=<mod>  Receive data with HDLC framing
        +FTS=<time> Pause for specified time
        +FRS=<time> Wait for a specified amount of silence on the line
        +FTM=?      Inquire available speeds/protocols
        +FRM=?      Inquire available speeds/protocols
        +FTH=?      Inquire avaialble speeds/protocols
        +FTH=?      Inquire available speeds/protocols



        5. TESTS

        Data throughput under 'everday' conditions: taken with a slow
        computer (8 MHz XT), Zmodem in Qmodem 4.31 und er DOS 3.3. A
        16550AFN UART was used, though.

        Scout+ to T2500   V.32 V.42bis    zipped          1050 cps
        Scout+ to T2500   V.32 V.42bis    textfile        1750 cps
        Scout+ to T3000   V.32bis V.42bis zipped          1600 cps
        Scout+ to Ultra   V.32bis V.42bis textfile        3300 cps
        Scout+ to USR DS  V.32 V.42bis    zipped          1050 cps
        Scout+ to USR DS  V.32 V.42bis    zipped          1620 cps

        Take a 486/50, DSZ Mobyturbo, enable write during receive and
        you can add most likely 5% to these numbers.

        These numbers were measured across the nation, Palo Alto to the
        East Coast.

        Modem delay:

        Scout+ one way from Palo Alto to the Nat'l Bureau of Standards
        time service in Boulder, Colorado, using their echo feature.
        The delay is 75 milliseconds at 1200 bps. About 1.3 milliseconds
        of this are caused by the 16550 buffer. Some other high-speed
        modems I am familiar with have slightly longer echo times. In
        this test the Scout+ compares well.

        Interactive response.

        I have installed the Scout+ on three different architectures:
        DOS, MacIntosh and my Sun. I tested the smoothness of the
        response by calling roughly 50 different modems over two
        continents. I find the interactive response on the DOS and Mac
        smooth and zippy when connected to Sun Multiprocessing systems,
        PCboard, Fido nodes or simple SunOS UNIX. I do spent quite a
        bit of time each day in interactive via modem. On the Sun on
        about every one of three screen updates there is a slight jerk
        noticable about half to three quarters down the 19" monitor.
        This may have to do with V.42bis translate table buffering. The
        Scout+ uses a 2048 byte translate table, but it can switch to
        smaller sizes if the other modem does not support this size.

        The DTE speed was 57.6k on DOS and Mac. Suns dont do 57.6, so
        it was 38.4k. Hardware flow control was enabled on DOS and Mac,
        but not on the Sun.

        The ping echo latency test is currently in revision. Once new
        test results are available with the newer ROMs and the higher
        clock speed I will include them. Ping latency is of concern
        when connecting UNIX computers via the Serial Line Internet
        Protocol (SLIP). The last values I measured were about 270
        milliseconds ICMP round trip echo delay over a 20 mile
        V.32bis V.42bis connection to a T3000.

        Signal Quality Monitoring:

        Signal quality monitoring is an optional feature in V.32bis.
        Some modems dont have it and are still V.32bis compliant. The
        Scout modems do have it and it is a feature I like. Essentially
        the bit error rate is monitored and if it exceeds a certain
        threshold a line retrain at the same speed (*Q1) is negotiated.
        Often this will then enable further data flow. If *Q2 is selected
        the modem can fallback to a lower speed or fall forward to a
        higher speed if the line quality improves again. The modem needs
        about 30 seconds of a clean line before it falls forward, much
        less than the 10 minutes of a clean line for the Telebit T3000.
        If you select *Q3 you allow the modem to disconnect if it can
        not achieve data throughput after several fallbacks. It has been
        my experience that modems without this feature lock up easier
        and eventually just disconnect.

        One can monitor the signal quality by typing ATSQ when
        connected.  The Scout then prints out a value between 0
        (lowest) to 7 (highest) about six times each second. This is a
        real time monitoring tool and very useful when trouble-
        shooting since it lets one decide quite easily if a problem
        is likley due to line noise or not.

        Testing the fax software was easy. The Scout is compatible with
        98% of fax machines installed at 9600 bps or less and Group 3.
        The software was easy to install and the first fax sent to a
        machine across town came out crisp. I then checked the receive
        side by faxing a letter with MCIMail's fax option to myself. I
        printed it out and again the first try worked. This was done
        under DOS 3.3 on an XT class machine.

        I have since used DosFax and the Scout+ to send faxes all over
        the world with little difficulty. One page to India takes about
        60 seconds of connect time, Japan, Thailand, Hongkong, Germany,
        Australia, Russia, Austria about 33 seconds. I can fax quite
        satisfactorily even into areas where data modems are known to be
        difficult to operate. The lower speed fax protocols in
        particular need rather low signal-to-noise ratios when compared
        to the corresponding data protocols.


        6. EPROM versions

        2413/2407 This was the first EPROM version shipped

        2521/2528 Shipped mid June 1992 and fixed some minor bugs:

                upgrade to Class 1 fax compatibility fixed US busy
                signal detection fixed flow control, can now be
                switched off reliably fixed USR 2400 bps connection
                problem

        2521/2624 Shipped mid August 1992

                fixed compatibility with Rockwell based modems fixed
                compatibility with Multitech 14,400

        2915/2930 Shipped mid October 1992

                bug: locks up occasionally on dialin use

        2A19/2930 Shipped end October 1992



        7. USES

        Lets look at the LEDs:

        Scout Plus, external model
        On the 5 1/2 by 1 1/2 front panel are 10 LEDS:

        MR      modem ready
        TR      terminal ready
        AA      auto answer
        EC      error correction
        HS      high speed
        RD      receive data
        SD      send data
        CD      carrier detect
        CS      clear to send (hardware flow control)
        OH      off hook

        Now lets look at the LEDS in action:

        . =  LED OFF
        O =  LED ON
        B =  LED BLINKING

        MR  TR  AA  EC  HS  RD  SD  CD  CS  OH

        .   .   .   .   .   .   .   .   .   .      power off

        O   .   .   .   .   .   .   .   .   .      power switched on, selftest

        B   .   .   .   .   .   .   .   .   .      failed hardware selftest

        O   .   O   .   O   .   .   .   O   .      power on

        O   O   O   .   O   .   .   .   O   .      terminal program started

        O   O   O   .   O   .   .   .   O   O      modem is dialing

        O   O   O   O   O   .   .   O   O   O      connected to online service

        O   O   O   O   O   O   .   O   O   O      receiving files

        B   O   O   O   O   O   .   O   O   O      file transfer error

        O   O   O   O   O   B   B   O   O   O      entering messages online

        O   O   O   .   O   .   .   .   O   .      logged out, offline again



        How does one call under severly impaired line conditions? Here
        is an an example calling to JV Dialogue in Moskow via direct
        dialing from Palo Alto, CA.

        SysOp: Pete Kvitek    <[e-mail]>

Online to JV Dialogue, Moskow:
at*o
MODEL:SCOUT PLUS
DTE:  57600  N81
DCE:  4800   MNP4            <-- V.32 at 4800 bps requires 16 db S/N only
RECEIVE LEVEL= -36 DBM

 E1  K1  M1  Q0  V1  X4 TONE
 &B0 &C1 &D3 &R2 &T5
 *E1 *F3 *G1 *M2 *N2 *P0 *Q3 *S1 *T1  <-- *Q3 allows the modem full line
                                          quality control
S00=001  S04=010  S08=002  S15=255
S01=000  S05=008  S09=000  S18=000
S02=043  S06=002  S10=003  S25=000
S03=013  S07=090  S12=050  S26=000 <-- S07 is doubled to 90 seconds to
OK                                     allow for the long dial completion
ato                                    delay
CONNECT 4800
EC/MNP4                 <-- with ato I go back from local modem
                                         to online JV Dialogue
        Created : 05-12-1992

        I use V.32 with fallback to 4800 bps, because this protocol
        requires only 16 dbm signal-to-noise. It is not often that one
        can get through to Moskow, and when I do I want to be sure to
        connect.


        8. TECH SUPPORT

        Here are the tech support options:

        1-408-262-1277  Digicom

        1-408-262-1390  Digicom fax

        1-408-262-1412  Digicom BBS

        comp.dcom.modems

        [e-mail]

        [e-mail]

        The warranty is for 5 years and is valid worldwide. If you would
        like to send your modem back to the manufacturer for warranty
        repair you need to obtain a Return Materials Authorization
        number from Digicom before you send it back.


        9. OTHER DIGICOM PRODUCTS

        9624LE+ series of V.32bis modems. They are offered in
        internal, external and in rack mounts with 16 modems per
        standard 19" rack.

        The 9624LE+ has been reviewed well in magazine tests:

        PC Week, April 29, 1991        Digicom was Analyst choice (the only)

        PC Week, November 19, 1990     Digicom is the only modem which gets
                                       five "good" rankings

        PC Digest Ratings Report Vol 5, 21
                                       Digicom is the only modem to get
                                       five stars, before USR and
                                       Forval

        9624E+ series of V.32bis modems. External with LCD display,
        4-wire leased line, V.25bis auto dial, also available in
        rack mounted version and with Network Management Support.

        Digicom pioneered modem DSP technology which allowed them the
        flexibility to be the first manufacturer to include
        send-receive fax in a V.32bis modem. They were also the first
        manufacturer to get a V.32bis modem to market. Since they
        develop the modem chipset in house, the speed and flexibility
        is higher than vendors who buy chipsets elsewhere like e.g.
        Hayes Microcomputers, which uses the Phylon chipsets, based on
        the TI DSP.

        Expect other 'firsts' from Digicom in the near future.

        The FT1 from Digicom is a fractional T1 DSU/CSU which is used
        on digital telephone circuits for line speeds between 64,000
        bps up to 1,536,000 bps in increments of 64,000 bps.


        NEW PRODUCTS

        In development is the softmodem, a device in which the modem
        software can be loaded in DSP RAM.

        A voice-mail upgrade together with switching between data,
        fax and voice is also anticipated.

        An upgrade for the Scout modem to the new Class 2.0 (not the
        old pseudostandard Class 2) fax interface will also be made
        available.

        Finally, a V.fast prototype has been in operation in Digicom's
        labs for some time now.



        10. ORDER INFO

        This is the complete package:

        Scout Plus modem
        Printed manual
        Quick Reference card
        Qmodem prepaid data communications software
        Delrina WinFax Lite 2.0 fax software
        Delrina DosFax Lite fax software
        Smith Micro Quicklink II data and fax (MacIntosh version only)
        hardware handshake/ARA cable (MacIntosh version only)
        RJ-11 extension cable
        Compuserve coupon, one month free trial membership
        Powersupply for external version (110 Volt or 185 to 240 Volts)

        Scout Plus PC  V.32bis/fax internal half card        $219
        Scout Plus     V.32bis/fax external                  $259
        Scout Plus MAC V.32bis/fax external                  $289

        Please add shipping and handling: $11.75 for UPS 2nd day.
        I accept cheques, CODs and VISA/Mastercards.

        Wolfgang Henke
        774 Wildwood Lane
        Palo Alto, CA 94303
        (415)-856-9037
        (415)-328-7518 (fax)
        [e-mail]
        [e-mail]
        support files ftp.rahul.net /pub/wolfgang

        International orders are welcome. They will be shipped with
        a 185 to 240 Volt power supply with either an US style three
        pronged grounded plug or a German style two pronged plug for
        the external modem. Please add airmail postage of about $35
        for Europe and $45 for Africa, Asia or Australia.

                                *    *    *

        Last but not least I would like to express my appreciation to
        the many experts I have met in comp.dcom.modems and computer
        bulletin boards and from whom I have learnt much and I hope
        will continue to do so in the future.


        Wolfgang Henke
        [e-mail]
        May 20, 1992
        revised June 27, 1992
        revised August 18, 1992
        revised October 31, 1992
        revised November 26, 1992
        revised December 20, 1992