Microcom
Encyclopedia
Microcom, Inc. was a major modem
vendor during the 1980s, although they were never as popular as the "big three", Hayes
, U.S. Robotics
(USR) and Telebit
. Nevertheless they hold an important place in modem history due to their introduction of the MNP
error-correction and compression protocols, which were widely used under license by most modem manufacturers in the 1990s. Compaq
purchased the company in 1997.
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 expensive microcontroller
to 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 capabilities. They developed a series of protocols that implemented simple packet-based file transfer protocol
s suitable 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 placed on existing modems with no 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 the AX/1200 and AX/2400 modems, which featured MNP 4 error correction in an otherwise standard 1200 bit/s Bell 212/v.22 or 2400 bit/s v.22bis modem. When a Microcom modem was used by both ends of a connection, the connection was entirely error-free.
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, notably AT&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 the Rockwell
chipsets would re-standardize the market on the Hayes-based commands.
Microcom continued developing the MNP standards, and later introduced the MNP 5 standard, 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 the AX/1200c and AX/2400c, the "c" for "compression". MNP 1 through 5 were later handed to the ISO
for standardization, and became widely available.
Microcom then developed the AX/9624c modem to answer the call to 9600 bit/s, introducing MNP 6. Competing companies offered 9600 bit/s products which typcically used proprietary modulation schemes. Microcom employed a variation of v.29 modulation 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 was also compatible with v.22bis.
Microcom introduced a new series of ever-faster modems, typically based on newly introduced standards. The first of these was the 9600 bit/s v.32-based QX/V32c, but the introduction of v.42bis compression system that easily outperformed MNP 5 led them to introduce the QX/4232, followed by the 14,400 bit/s QX/4232bis when the v.32bis standard 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 the DeskPorte series as their primary desktop modem, the OfficePorte which was similar but added fax
capabilities, and the TravelPorte or TravelCard series of PC 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 winning Carbon Copy
remote control and file transfer software, LANlord
desktop/PC management software, Microcom Bridge Router [MBR] and a centralised dial pool system LANexpress which was used by service providers for the first deployments of dial in ports for the early adopter internet and bulletin board users.
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
vendor during the 1980s, although they were never as popular as the "big three", Hayes
Hayes Microcomputer Products
Hayes Microcomputer Products was a U.S.-based manufacturer of modems. They are particularly well known for their Smartmodem, which is introduced the ability to control the modem through commands sent in the data stream itself. The "smart modem" approach dramatically simplified operation, making...
, U.S. Robotics
U.S. Robotics
USRobotics Corporation is a company that makes computer modems and related products. It sold high-speed modems in the 1980s, and had a reputation for high quality and compatibility. With the reduced usage of voiceband modems in North America in the early 21st century, USR is now one of the few...
(USR) and Telebit
Telebit
Telebit was a US-based modem manufacturer, most notable for their TrailBlazer series of high-speed modems. One of the first modems to routinely exceed 9600 bit/s speeds, the TrailBlazer used a proprietary modulation scheme that proved highly resilient to interference, earning the product an almost...
. Nevertheless they hold an important place in modem history due to their introduction of the MNP
Microcom Networking Protocol
The MNP family of error-correcting protocols were commonly used on early high-speed modems. Originally developed for use on Microcom's own family of modems, the protocol was later openly licensed and used by most of the modem industry, notably the "big three", Telebit, USRobotics and Hayes...
error-correction and compression protocols, which were widely used under license by most modem manufacturers in the 1990s. Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
purchased the company in 1997.
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 expensive microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
to 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 capabilities. They developed a series of protocols that implemented simple packet-based file transfer protocol
File Transfer Protocol
File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...
s suitable 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 placed on existing modems with no 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 the AX/1200 and AX/2400 modems, which featured MNP 4 error correction in an otherwise standard 1200 bit/s Bell 212/v.22 or 2400 bit/s v.22bis modem. When a Microcom modem was used by both ends of a connection, the connection was entirely error-free.
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, notably AT&T Paragon
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
'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 the Rockwell
Conexant
Conexant Systems, Inc. is an American semiconductor company, formerly the semiconductor division of Rockwell International. Currently it's privately owned by Golden Gate Capital, an equity firm headquartered in San Francisco.-History:...
chipsets would re-standardize the market on the Hayes-based commands.
Microcom continued developing the MNP standards, and later introduced the MNP 5 standard, 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 the AX/1200c and AX/2400c, the "c" for "compression". MNP 1 through 5 were later handed to the ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
for standardization, and became widely available.
Microcom then developed the AX/9624c modem to answer the call to 9600 bit/s, introducing MNP 6. Competing companies offered 9600 bit/s products which typcically used proprietary modulation schemes. Microcom employed a variation of v.29 modulation 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 was also compatible with v.22bis.
Microcom introduced a new series of ever-faster modems, typically based on newly introduced standards. The first of these was the 9600 bit/s v.32-based QX/V32c, but the introduction of v.42bis compression system that easily outperformed MNP 5 led them to introduce the QX/4232, followed by the 14,400 bit/s QX/4232bis when the v.32bis standard 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 the DeskPorte series as their primary desktop modem, the OfficePorte which was similar but added fax
Fax
Fax , sometimes called telecopying, is the telephonic transmission of scanned printed material , normally to a telephone number connected to a printer or other output device...
capabilities, and the TravelPorte or TravelCard series of PC Card
PC Card
In computing, PC Card is the form factor of a peripheral interface designed for laptop computers. The PC Card standard was defined and developed by the Personal Computer Memory Card International Association which itself was created by a number of computer industry companies in the United States...
-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 winning Carbon Copy
Carbon Copy (software)
Carbon Copy was an early remote control and file transfer software for DOS and Windows published by Microcom. It allowed remote access to a computer via dial-up modem connection...
remote control and file transfer software, LANlord
LANlord
LANlord was a DOS, Windows, and OS2 workstation management system originally developed by Client Server Technologies Group, which got seed funding from Microcom who ultimately later sold the LANlord group in February 1994 to Central Point Software .LANlord offered a client–server architecture...
desktop/PC management software, Microcom Bridge Router [MBR] and a centralised dial pool system LANexpress which was used by service providers for the first deployments of dial in ports for the early adopter internet and bulletin board users.