Microcom

For the "Concentrate. Because it's cheaper" telecommunications hardware company, seeMicom.

Microcom, Inc.,was a majormodemvendor during the 1980s, although never as popular as the "big three",Hayes,U.S. Robotics(USR) andTelebit.Nevertheless, Microcom holds an important place in modem history for introducing theMNPerror-correctionandcompressionprotocols,which were widely used under license by most modem manufacturers in the 1990s. The company went public in 1987.Compaqpurchased publicly outstanding shares of the company in 1997.

Microcom, Inc.

Company type	Telecommunications
Founded	1980(1980)inNorwood, Massachusetts
Founder	James M. Dow
Defunct	1997(1997)
Fate	Acquired byCompaq
Products	Modems

History and products

Microcom was founded in 1980 by James M. Dow fromData General.

In the mid-1980s several companies introduced new modems with various "high-speed" features in order to differentiate themselves from the growing legion of Hayes 1200 bit/s clones that were flooding into the market. Developing such a protocol was not all that easy, and generally required a fairly powerful and expensivemicrocontrollerto handle the modulation. For companies with limited resources, entering this market was difficult.

Microcom took another approach, addressing the feature gap not through higher speeds, but through additional software capabilities. They developed a series of protocols, known collectively asMicrocom Networking Protocol(MNP),that implemented simple packet-basedfile transfer protocolssuitable for implementation on very simple microcontrollers. The differences were primarily in how difficult the protocol was to implement, with MNP 1 being extremely simple allowing it to be implemented on many existing modems with no hardware changes, while MNP 4 offered much better throughput at the cost of increased memory needs, which modems typically had little of (40 bytes was common).

Microcom introduced their own modems starting with theAX/1200andAX/2400modems, which featured MNP 4 error correction in an otherwise standard 1200 bit/sBell 212A/V.22or 2400 bit/sV.22bismodem. When a Microcom modem was used by both ends of a connection, the connection was entirely error-free.

Microcom continued developing the MNP standards, and later introduced MNP 5, which compressed the data in the modem before sending it, thereby actually increasing the data rate while still being error-free. MNP 5 was introduced on theAX/1200candAX/2400c,the "c" for "compression". MNP 1 through 5 were later handed to theISOfor standardization, and became widely available.

Microcom then developed theAX/9624cmodem to answer the call to 9600 bit/s, introducing MNP 6. Competing companies also offered 9600 bit/s products, but these were all based on proprietary modulation schemes. Microcom employed a variation ofV.29modulation which is half-duplex 9600 bit/s. MNP 6 utilized the compression of MNP 5, and with the fast training capability of the Rockwell V.29 devices. the AX/9624c achieved full-duplex 9600 bit/s at a price lower than its competitors. Like other 9600 bit/s modems, it was required to have the same hardware on both ends of the link, however, the modem also supported V.22bis at 2400 bit/s.

Microcom introduced a new series of ever-faster modems, typically based on newly introduced standards. The first of these was the 9600 bit/sV.32-basedQX/V32c,but the introduction ofV.42biscompression system that easily outperformed MNP 5 led them to introduce theQX/4232,followed by the 14,400 bit/sQX/4232biswhen theV.32bisstandard was ratified. Microcom and Rockwell became partners on a number of ventures, including the creation of the MNP 10 and MNP 10EC protocols, and Microcom increasingly used Rockwell chipsets across their line.

The company also broadened its line into different price points, offering theDeskPorteseries as their primary desktop modem, theOfficePortewhich was similar but addedfaxcapabilities, and theTravelPorteorTravelCardseries ofPC Card-based products for portable users. These all had the added benefit of allowing the user the option using the parallel port as a communications port, which offered a faster throughput - this was achieved by using a re-director software developed by Microcom.

Microcom also had a range of other products including the award-winningCarbon Copyremote control and file transfer software,LANlorddesktop/PC management software,Microcom Bridge Router(MBR), a centralised dial pool systemHigh Density Modem System(HDMS) which was used by service providers for the first deployments of dial-in ports for the early adopter internet and bulletin board users, andLANexpress,a corporate remote access solution.

Command sets

In order to control these new features, Microcom introduced a series of new command switches prefixed with the backslash,\,while retaining the extended commands used in the Hayes Smartmodem 2400, prefixed by the ampersand,&for things like carrier detection and speed selection. As other companies increasingly used the MNP protocols, many chose to keep the original commands specified by Microcom, notablyAT&T Paragon's chipsets which were fairly popular in the early 1990s. Hayes instead chose to introduced their own set with additional&-prefixed commands, USR an incompatible set of&-prefixed commands, and Telebit added to their already bewildering array of setup registers. It would be many years before the complete dominance of theRockwellchipsets would re-standardize the market on the Hayes-based commands.

Patent settlement

In 1993 Microcom settled a lawsuit against them bySpectrum Information Technologiesvia a consent decree that resulted in "a cross-licensing agreement for patents."