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Text file describing various 9600 Baud modems, V.32 and V.42 compression.
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Text file describing various 9600 Baud modems, V.32 and V.42 compression.
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Contents of the 9600DATA.TXT file

Filename: 9600DATA.TXT
Version : 1.2b
Updated : 1/11/1991

A Comparason of High Speed Modems

Including: HST, V.32, V.32bis, V.42, V.42bis

USR HST/V.32bis (805) 494-9386
USR HST 14.4k (805) 497-3456
CC Speedmodem (805) 496-7320
FidoNet 1:206/2801

A High Speed Modem
Half-Duplex Vs. Full Duplex
What is MNP, HST, V.32, V.42 ect.
What to look for: Throughput, Configurability, UARTS, Ect.
Some Questions to ask: If Considering a generic V.32/V.42.
Some Questions to ask: If Considering a FAX/Modem.
Modem Manufacturer Phone Numbers.
Modem Compatibility Listing.
Modem Price Comparisons.
Document Updates.

A High Speed Modem

Are you thinking of going to a High speed modem?

2400 baud can be very slow for transfering large files.
Modems advertised as 4800 are really only 2400 with data compression such
as MNP-5 or even just software data compression. Don't be fooled.
A 9600 or faster modem will make a tremendous difference on your transfer time.
Most 9600 Baud users never want to go back to 2400. There is a lot of confusion
and mis-information about 9600 Baud and faster Modems. I wrote this to help
clarify and point out the differences between the different modems available
for MS-DOS machines.

If price is no object, the Best modem to get for BBS use is the USRobotics
Dual Standard. It is a combination of the HST 14400 Baud modem and a
V.32/V.42 modem all rolled into one modem.

If price is an Issue, (like it is to most people) then you may want to consider
a Standard HST 14.4k, or a different Brand if that is also too expensive.
But if you do not buy a USRobotics Modem, you will not be able to hook up to
a Standard USR HST 14.4k, which is the most Common BBS Modem.

Other then USR, you could get a V.32 or V.32/V.42 compatable modem for about
25% less then a Standard HST, or you could get a 9600 FAX/Modem for less then
half the cost of a V.32 See the price comparisons at the end.



This information was obtained from several reputable sources, but none
of it is guaranteed to be 100% accurate. I am not responsible for any
incorrect information in this document, nor am I responsible for any
loss of profits to anyone resulting from reading the information in this
documentation. Proceed at your own risk.


Corrections and updates

Since new modem brands, models, and new prices are appearing constantly,
this documentation is going to need a lot of updating. Also some of the Current
Information may need corrections as well. You are welcome to make changes to
this information, but please send me a copy of your update so that I can add
your changes to the current latest version I have. That way all the corrections
that are made will be added to the latest version, which will also be avail.
for download on my bbs.



At one Time Hayes was the standard in modems. All other modems tryed to be
"Hayes Compatible". This is still true with 1200 and 2400 bps modems,
but NOT when it comes to 9600 or faster modems. Hayes established a Standard
called the AT command set. Other modem manufacturers quickly adopted this
standard and the AT commands are still used today (with a few commands added).

Well Along Came USRobotics, and designed the HST, a proprietary 9600 modem
that quickly became popular, and no one else was allowed to duplicate.
Hayes then also came out with a proprietary 9600 modem, but since it could not
talk to the HST at 9600 it never became popular in the IBM world.
Next USR improved their HST modem, making it transfer at 14400 bps without
even using data compression.
USR's HST became the standard for MS-DOS compatable High Speed modems.

Realizing that the industry needed a "non-proprietary" 9600 standard that
any manufacturer could use, the CCITT came up with the V.32 specification.
It took a several years before modem manufactures started finding ways to
implement this standard at a price competitive to HST, but a few manufactures
started producing them, including Hayes. Next the CCITT relized that better
error correction and data compression methods existed, and thus came up with
the V.42 and .V42 bis standard. They are currently finalizing the V.32bis
specification, which will also run at 14,000 Baud in full duplex.

Now Modem Manufactures all seem to be jumping on the V.32 Bandwagon,
Even USR offers V.32/V.42 modems and allows the HST's to be upgraded to
a "Dual-Standard" so it can be both HST and V.32/V.42 in one.
The New HSTs also have V.42bis and can be upgraded to the new V.32bis DS.
The price Difference between the HST and the HST-DS is considerable though,
which is why Most BBS Sysops still buy the HST without the "DS" option.
The V.32/V.42 have become the standard in the Macintosh world, and some
MS-DOS BBS's are now running V.32/V.42 instead of supporting the HST,
and some are supporting both types, using multiple lines.

Fax Machines have had their own standards, CCITT V.27, V.27ter, and V.29
define the modulation scheme used for Fax, and T.30 defines a Fax Protocol.
Fax Machines nowdays can transfer Faxs at 4800 or 9600 Baud. Most Fax/Modems
can only transfer files at 2400 Baud. There is now one Fax/Modem which can
also transfer files at 9600 bps, and is far less expensive then the V.32/V.42s,
plus offer the benefits of a Fax machine.



The International Consultive Committee for Telegraph and Telephone (CCITT)
set the V.32, V.42, and V.42bis Standards in 9600 bps communications.
They have also set the standards of 1200 and 2400 bps in Europe.
Unfortuntly the V.32 standard is very expensive to implement for the
modem manufactures, and the HST has already become the industry standard
in the IBM BBS world. But since any company may manufacture V.32/42 Modems
without a licence or royalty, there is more price-competition going on
with these then with the HST, which currently has no true competition.


Half Duplex Vs. Full Duplex

Half-Duplex is When Data is Transmited in one Direction at a time.
Full-Duplex is both directions at once. 2400 buad modems are Full-Duplex.
The HST Modem uses an improved form of Half-Duplex, in which one direction is
transfering at high speed while the other direction is sending ACK/NAK signals
at a slower speed. A simular method is used on the Speedmodem.

V.32 modems use Full duplex, which in most cases does not improve performance
when used on a BBS. There is one way to take full advantage of a Full-Duplex
Modem: By using a protocol called Bimodem to upload and Download as the same
time at 9600 bps in each direction! Unfortunately Bimodem has not become very
popular. Most BBS's and users still use one direction transfer protocols such
as Zmodem or YModem-G.


What is MNP, HST, V.32, V.42?


MNP (Microcomm Network Protocol) levels 1-4 are methods of error correction
in which the two modems connected verify the integrity of the data transmitted.
Error correction is required for several streaming protocols such as Ymodem-G
in which the protocol sends a constant stream of data and lets the modems do
the error correction. This requires a clean, noise free line as streaming
protocols will abort if line noise interferes too much.
These MNP Levels are used in almost all High Speed Modems Made today, But
Just because two modems both have MNP it does not ensure that they will both
talk to each other (at over 2400 baud).

MNP Level 5 is for data compression. Since All BBS's have their files archived
in ZIP, LZH, GIF or some such compressed format (try to ZIP a LZH file), MNP5
can actually increase the overhead by attempting to compress the file further.
Therefore BBS's leave MNP5 turned off, and so should the BBS callers.



HST stands for "High Speed Technology" - a method of communicating at high
speeds whech was developed by US Robotics in 1984. HST is a proprietary
method so currently only US Robotics is allowed to Make HST Compatible Modems.
The original HST modems were 9600 bps by using a 9200 bps channel in one
direction and a 450 bps "back channel" in the other to send ACK/NAK
signals for confirmation of data - a half duplex mode - often referred to
as "ping-ponging". In 1989 USR improved the HST to run at 14400 bps by further
optimizing their proprietary method. All HST's sold now include the 144k
speed as well as the original 9600 mode. Because the HST 14.4k is a raw speed,
It allows the HST to transfer pre compressed files such as ZIPs at faster
speeds then any other 9600 modem: over 1700 Characters per second.

The HST has become the "BBS-Standard" in high-Speed Modems. More BBS's use
the HST then any othe type of modem, including the V.32.

As of January 1st 1991 all HST modems also include the V.42/V.42bis error
correction and data compression (not to be confused with V.32).

The HST's can also be upgraded to the HST "Dual Standard" allowing it to also
be V.32bis compatable. The price is significant for this upgrade however,
and in very few cases is any speed gained.



V.32 is a 9600 Baud standard that was established by the CCITT back in 1984.
V.32 is full duplex (9600 bps in both directions at once). Normally this would
be impossible, but using a technique called "echo cancellation", one modem
can filter its own tones from the phone line, enabling it to pick out the
signals from the other modem. However, echo cancellation requires that high
speed modems include built-in digital signal processor (DSP) chips, which is
the main reason V.32 and V.42 costs so much.
V.32 also includes a fallback to 4800, if line noise becomes a problem at 9600.
The V.32 standard also provides an optional error-reduction sceme, called
"trellis-coded modulation (TCM). TCM allows 9600 modems to check for
transmision errors with a redundancy bit, which results in fewer errors on
noisy lines. Most V.32's include this option, but some do not.



It was first realized in 1989 that it is feasible to push V.32 up to 14,400
baud, the same speed as the HST now runs. This requires even better echo
cancellers and an overall improvment in reciver quality, so it will be
more costly to produthen the V.32 to produce. V.32bis has not yet officially been
finalized CCITT, but as of January 1st US Robotics has started shipping
a new version of their Dual Standard Modem which includes V.32bis in an early
but functional form. USR plans to update their DS ROMS when the CCITT actually
release the completed V.32bis specification, scheduled for mid 1991.
It's expected that other Modem manufacturers will not be able to offer the
V.32bis technology untill the 4th quarter of 1991.



V.42 is nothing to do with actual modem speed, but how how the error correction
and data compression schemes interface. When the CCITT approved V.42 in 1988,
they desided to include two differnt error correction and data compression
schemes. The first one is MNP,(short for Microcom Networking Protocol).
MNP classes 2, 3, & 4 which handle error correction. Note that MNP-5 was not
included in the V.42 standard because it is only used for data compression.
MNP was made an offical standard due to the large number of modems that
currently use it. The Second method is the prefered method, known as LAP-M
(Link Access Protocol-Modem). A modem with only MNP is called "V.42 Compatible"
and one with LAP-M its known as "V.42 Compliant". If a V.42 Compliant connected
to a V.42 compatible, it would first try to Handshake with LAP-M, and after it
relized that the othe modem is not Compliant, it would try the MNP Method, and
they connect.

Most V.42 modems are fully V.32 compatable, but they do NOT have to be,
according to CCITT guidelines. So when purchasing a V.42, make sure that
it is really a V.32 Modem that is also V.42 complient or compatable.
There are now some 2400 baud modems which are also V.42bis compliant,
so since the LAP-M gives 4:1 data compression they are advertised as
"9600 throughput", which really can be misleading and confusing.



V.42bis is a new CCITT standard for data compression techniques, which was
appoved in late 1989. To Support V.42bis, a modem MUST support both LAP-M and
MNP-5, unlike the Standard V.42 in which LAP-M is only an option. V.42 provides
a maximum data compression of 4:1, giving a 9600 bps modem a throughput up to
38400 bps. MNP only offers 2:1 Compression. Like MNP-5, LAP-M and V.42bis will
not be effective when transfering compressed files from BBS's, such as ZIP
files. Since V.42 is implemented in firmware, many V.42 complient modems can
be upgraded to V.42bis with a new ROM.



A less expensive method of 9600 bps communication can be achieved without
using the CCITTs method of "echo cancellation", so that the a digital signal
processor is not needed, making the cost much less expensive.
This method is used on the Compucom Speedmodem. The Speedmodem also uses
Dynamic Impedance Stabilization (DIS) to increase the relability of the
telephone interfaces signal-to-noise ratio of the telephone line by increasing
the clarity and power of the signal, and automatically compensating for
impedence variations on the phone line. This reduces the probibility of
line noise, allowing the Protocols to transfer files with less overhead
It also has a faster fallback rate of 7200 bps if too much line noise exists
for 9600 communications. This makes the Speedmodem stand up to worse line
noise conditions at a faster rate then V.32 can handle.
The Speedmodem is also a 9600 bps Group III Facsimile, so with this modem,
you can send document and scanned images as a Fax, as well as recive Faxs.
It supports BitFAX by Bitcom and any other 3rd party FAX software which
uses the standard CCITT AT-FAX command set.
A Data Compression called CSP (CompuCom Speed Protocol) is used to yeld a
compression of up to 4:1, giving a throughput of up to 38400 bps.
This however, like MNP5 will not be effective when transfering compressed
files from BBS's, such as ZIP files.

DIS and CPS are proprietary methods owned by CompuCom, Sunnyvale, CA.
Because this modem is inexpensive more people can afford to buy it, and since
its both a FAX and a Modem in one, it should gain popularity quickly.
It is still a new product, but hundreds of BBS's are showing support for it.

What Next?

By mid 1991 the V.32bis standard will be finialized, and by that years end
the several 14,400 Bps full duplex modems will be on the market.
There is already talk of the CCITT releasing another standard in 1992,
which will be for 192,000 bps. Since these modems are expected to cost
consideribly more then the V.32s currently on the market, they will be
out of the price range of most BBS users.




You'll see ads claiming that you can attain 19,200 bps or 38,400 bps
with a 9600 Baud modem - this is true only if you are using MNP5 or other
form of data compression on an uncompressed data or text file. Any 9600 Baud
modem using compression will transfer at that effective rate.
But for BBS use, where files are already compressed (such as ZIPs, LZHs, GIFs)
MNP5 will actually slow down throughput by attempting to compress a file that
is already compressed. Generally when using a modem for BBS transfers, its
the RAW speed of the Modem and not the throughput which is important.

Figures of around 1700 cps by the HST modems are attained through proprietary
methods not available on other modems.

In High Speed Modems, there is a lot more to configure than on a 2400 Baud
modem. Be sure your modem comes with NRAM (Non-volatile Random Access Memory)
that can store your modem configuration, making long init strings unnessesary.
Also many modems have dip switches to set the default configuration, which
also simplys things. If you buy an Internal Modem, be sure its fully
Configurable as far as selecting the com port and IRQ (interupt request)
setting. Some modems can be addressed from Com1: up to COM8:

Internal Modems have a serial port built in, and External Modems use an
existing Serial Port in the computer. A serial port has a UART chip to buffer
and control the Input/Output (I/O). The XT usually has an 8450 UART which will
handle up to 9600 Baud. The AT usually has the 16450. If you have an external
modem you should replace your UART with the 16550 (NS16550AN).

MS-DOS Users can choose internal modems, that plug in a computers slot,
or external, which plugs into an existing serial port with a serial cable.
Internals are usually less expensive, take up less space, have the correct UART
already installed (see below) and don't need a cable. But the Externals usually
have a lot of little lights on it that you can stare at, and its easier to move
to another machine. So which ever you prefer (or is available in some cases).

If Considering a USRobotics Modem
You only need to worry about weather you want the HST
(which can be upgraded later), or the Dual Standard
which is the same modem with the V.32bis option included.

If Considering a V.32/V.42 Modem
Some questions to ask:

Can you afford the USR "DS" instead?
Is it both V.32 and V.42 compatible?
Is it V.42 compatible, V.42 compliant, or V.42bis?
If its not V.42bis or compliant, can it be upgraded?
Do Local/National BBS's support it?
Would you rather wait a year for a V.32bis?
What is the warranty? 5 years?

If Considering a FAX/Modem
some questions to ask:

Is it Send and Recive Fax?
Does it support 3rd party FAX software?
Is it 4800 or 9600 bps?
Does it support MNP?
Does it support other compression?
Do Local/National BBS's support it?
What is the Warranty? 5 Years?


Modem Compatibility Listing:

These modems will usually be downwardly compatible with 2400 Baud and slower
modems, Which means they are also CITTY V.22bis and Bell 103/212A compatible.
Most have an auto-fallback mode that will detect the highest negotiable Baud
rate, which can either through hardware or software configuration.
If the modem is V.42 capable, it will fall back to MNP if the other modem is
not LAP-M capable, but is MNP capable. Modems supporting MNP will connect
with data compression/error correction with other MNP modems at the highest
Baud rate negotiable between the two. The speeds listed here are the actual
Raw speed, not possible throughput that can be achieved using data compression.

Listed in alphabetical order by brand name -

Generic V.32 only
Made by a number of companies using the CCITT method of communicating at
9600 bps.
These are expected to become outdated as V.42 is added to most V.32 modems
- Talks to other brand V.32 modems at 9600 Baud.

Generic V.42 Only
If a Modem is V.42 or V.42bis only, and not V.32, then it can only talk to
other V.42 modems at 2400, (with 9600 throughput using data compression)
This is not considered a 9600 Modem and should be avoided.
- Talks to other brand V.42 modems at 2400 Baud with LAP-M.

Generic V.32/V.42 (and V.42bis)
These modems follow BOTH the CCITT V.32 and V.42 standards for
communicating at 9600 bps.
- Talks to other brand V.32 modems at 9600 Baud.
- Talks to other brand V.42 modems at Top Supported Baud.

(Some Generic Brands include: Anderson Jacobson, Codex, Computer Periphels,
Digicom, E-Tech, Farallon, Fastcomm, General Datacom, Intel, Magic, Mastercom,
Microcom, Multi-tech, NEC, Practical Peripheals, Prometheus, Radcal Vadic,
Shiva, Telebit, Telenetics, USD, and many others just appering
Some of these offer LAP-M and V.42bis, and some do not.)

Hayes V-Series:
The early Hayes V-Series uses a proprietary method of communicating at
9600 bps.
- Talks other Hayes V-Series modems at 9600 Baud.

Hayes V-Series V.42:
The Hayes V-Series V.42 uses the proprietary method of communicating at
9600 Baud but will incorporate the V.42 data compression and error checking
- Talks to other V.42 modems at 2400 with error correction/compression.
Talks to other MNP modems at 2400 using error correction/compression.
Talks to other Hayes V-Series at 9600.

Hayes ULTRA:
Uses CCITT V.32 and V.42bis method for communicating at 9600 Baud.
Has MNP5 abilities.
Has LAP-M abilities
- Talks to Other V.32 modems at 9600 Baud
Talks to other V.42 modems at up to 9600 Baud
Talks to other Hayes V-Series at 9600

Telebit Trailblazer:
Uses proprietary PEP method of communicating at 9600 Baud.
Has MNP5 abilities.
- Talks to other Telebit Trailblazers at 9600.
Talks to other MNP modems at 2400 baud with error correction/compression

USR Courier V.32:
Uses CCITT V.32 and V.42 method of communicating at 9600 Baud.
offers MNP5 abilities.
- Talks to Other V.32 modems at 9600 Baud.
Talks to Other V.42 modems at up to 9600 baud
USR Courier HST: (old version)
Uses the USR proprietary HST method of communicating at 9600 Baud.
Has MNP5 abilities.
- Talks to HST type modems at up to 9600 Baud.

USR Courier HST 14.4:
Uses the USR proprietary HST method of communicating at 9600 Baud.
Has MNP5 abilities.
- Talks to HST DS's at 14,400 Baud
Talks to HST 14.4's at 14,400 Baud
Talks to HST's at 9600 Baud

USR Courier HST DS:
The Dual Standard incorporates both the proprietary HST method of
communicating at 14400 baud and the and the CCITT V.32 & v.42 methods of
communicating at 9600 Baud. (and V.32bis after 1/1/1991)
Has MNP5 abilities.
- Talks to Other V.32 modems at 9600 Baud.
Talks to Other V.32bis modems 14,400 Baud.
Talks to Other DS's at 14,400 Baud
Talks to 14.4 HST's at 14,400 Baud
Talks to old 9600 HST's at 9600 Baud.

COMPUcom Speedmodem/Fax:
Uses the Proprietary DIS at 9600 Baud.
Has 7200 and 4800 Baud Fallback
Has CCITT FAX V.27ter & V.29
Has MNP5 abilities.
Has CSP abilities.
Talks to Group III Faxs at 9600.
-Talks to Speedmodems at 9600.
Talks to other MNP modems at 2400 with error correction/compression

Manufacturer Toll Free Charge Call Support BBS
============ ============== ============== ==============
Anchor (800) 541-2318
Anderson Jacobson (800) 438-8520 (408) 435-8520
Codex (508) 261-4000
Compucom (800) 228-6648 (408) 732-4500 (408) 738-4990
Computer Peripherals (800) 854-7600 (805) 499-5751 (805) 499-9646
Digicom (800) 574-2730
E-Tech (408) 982-0270
Farallon (415) 596-9100
Fastcomm (800) 521-2496 (703) 620 3900
General Datacom (203) 574-1118
Hayes (800) 241-9625 (404) 441-1617 (800) 874-2937
Intel (800) 538-3373 (503) 645-6275
Magic Modems (800) 622-3475
Mastercom (213) 834-6666
Microcomm (800) 822-8224 (617) 551-1000
Multi-Tech (800) 328-9717
NEC (800) 222-4632 (408) 433-1250
Practical Peripherals (800) 442-4774 (818) 706-0333
Promethues (800) 477-3473 (503) 624-0571
Radcal Vadic (800) 482-3427 (408) 432-8008
Radcal Milgo (800) 327-7909 (305) 846-1601
Shiva (800) 458-3550 (617) 864-8500
Telebit (800) 835-3248 (408) 734-4333
Telenetics (800) 822-4267 (714) 779-2766
USD (800) 631-4869 (205) 430-8000
USRobotics (800) DIAL-USR (708) 982-5001 (708) 982-5092


Price Comparasons

No Prices have been stated above this Section, because prices often change,
and I want to keep all the prices together so they could be quickly updated
as needed. There are 3 types of prices I will cover. First is The Retail price,
second is the Sysop price, which is only available if you run a BBS.

Many Modem Manufactures offer BBS Sysop special prices directly, at about
50% off the retail price. First the BBS has to be verified, so the modem
manufacture knows that is is a real BBS that has been running for at least
6 Months, and has a minimum number of users, ect. Usually the Manufacturer
will call the BBS once, or twice a few week apart to be sure. Verification
usually take 3-4 weeks. Then the Sysop has to agree to use the Modem on the
BBS for some set amount of time.

Generic Brands Retail Sysop

V.32 Only EXT $650-$1,000 ????
V.32/V.42 EXT $700-$1,000 ????
V.32/V.42bis EXT $700-$1,200 $339+

Software Included: Varies
Warranty: Varies 1-5 years
Hayes Retail Sysop

Ultra V.32/V.42 $1,199 $599
V-Series V.42 (not V.32) $999 $499
V-Series 9600 $799 $399

Software Included: None
Warranty: 2 years
Compucom Retail Sysop

SpeedModem/Fax INT $279 $169

Software included: BitFax
Warranty: 5 years
Intel Retail Sysop

9600EX $799 $399

Software included: None
Warranty: 5 years
Practical Peripherals Retail Sysop

V.32/V.42 EXT $699 $339
V.32/V.42 INT N/A N/A

Software Included: None
Warranty: 5 Years

Note: Due to many reports of Incompatibilities/Problems from Owners
of these new P.P. Modems, I would not currently recomend them, although
they are currently the lowest priced V.32 I have seen.

Telebit Retail Sysop

T1000 ??? ???
T1500 V.32 ??? ???
TrailBlazer INT ??? ???
Trailblazer EXT ??? ???
T2500 V.32/V.42 ??? ???

Software Included:None
Warranty: 5 years
USRobotics Retail SysOp

Courier Dual Standard E $1,595 $699
Courier Dual Standard I $1,395 $649
Courier V.32/V.42 EXT $1,099 $599
Courier V.32/V.42 INT $949 $577
Courier HST 14.4 EXT $995 $449
Courier HST 14.4 INT $895 $405
DS Upgrade Kit for HST EXT $600 $300
DS Upgrade Kit for HST INT $500 $250

Software included: None
Warranty: 2 Years
Document updates:

Date Release Comments
---- ------- --------
10/30/90 1.0 Inital Release. Should have run a spell checker!
11/08/90 1.1 Spelling fixes, V.32bis update, Compucom update
01/10/91 1.2 USR V.32bis Update, other minor corrections
01/11/91 1.2b Speedmodem Corrections submited to Remco Treffkorn
for feedback (not for public relese)
** End-of-file **

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