BitCom was the software I wrote for the Winmodem/softmodem.  It was archived on a disk. Before it could be written, a whole lot of network protocols and standards had to be agreed, such as the basic 8-bit byte itself, and parity checking.

The next major advance in modems was the Smartmodem, introduced in 1981 by Hayes Communications. The Smartmodem was an otherwise standard 103A 300-bit/s modem, but was attached to a small controller that let the computer send commands to it and enable it to operate the phone line. The command set included instructions for picking up and hanging up the phone, dialing numbers, and answering calls. The basic Hayes command set remains the basis for computer control of most modern modems.

Prior to the Hayes Smartmodem, dial-up modems almost universally required a two-step process to activate a connection: first, the user had to manually dial the remote number on a standard phone handset, and then secondly, plug the handset into an acoustic coupler. Hardware add-ons, known simply as dialers, were used in special circumstances, and generally operated by emulating someone dialing a handset.

With the Smartmodem, the computer could dial the phone directly by sending the modem a command, thus eliminating the need for an associated phone instrument for dialing and the need for an acoustic coupler. The Smartmodem instead plugged directly into the phone line. This greatly simplified setup and operation. Terminal programs that maintained lists of phone numbers and sent the dialing commands became common.

The Smartmodem and its clones also aided the spread of bulletin board systems (BBSs). Modems had previously been typically either the call-only, acoustically coupled models used on the client side, or the much more expensive, answer-only models used on the server side. The Smartmodem could operate in either mode depending on the commands sent from the computer. There was now a low-cost server-side modem on the market, and the BBSs flourished.




News wire services in 1920s used multiplex equipment that met the definition, but the modem function was incidental to the multiplexing function, so they are not commonly included in the history of modems.

TeleGuide terminal

Modems grew out of the need to connect teletype machines over ordinary phone lines instead of more expensive leased lines which had previously been used for current loop-based teleprinters and automated telegraphs. In 1943, IBM adapted this technology to their unit record equipment and were able to transmit punched cards at 25 bits/second.[citation needed]


A PCI Winmodem/softmodem (on the left) next to a traditional ISA modem (on the right).

A Winmodem or softmodem is a stripped-down modem that replaces tasks traditionally handled in hardware with software. In this case the modem is a simple interface designed to create voltage variations on the telephone line and to sample the line voltage levels (digital to analog and analog to digital converters). Softmodems are cheaper than traditional modems, since they have fewer hardware components. One downside is that the software generating and interpreting the modem tones is not simple (as most of the protocols are complex), and the performance of the computer as a whole often suffers when it is being used. For online gaming this can be a real concern. Another problem is lack of portability such that non-Windows operating systems (such as Linux) often do not have an equivalent driver to operate the modem.

Apart from the acoustic or phone modem I used a Evergreen State College, the first digital modem I used in 1990 came with BitCom software.
n 1985, Thom Henderson of System Enhancement Associates wrote a program called ARC,[1] based on earlier programs such as ar, that not only grouped files into a single archive file but also compressed them to save disk space, a feature of great importance on early personal computers, where space was very limited and modem transmission speeds were very slow. The archive files produced by ARC had file names ending in ".ARC" and were sometimes called "arc files" as a result.

The source code for ARC was released by SEA in 1986 and subsequently ported to Unix and the Atari ST in 1987 by Howard Chu. This more portable code base was subsequently ported to other platforms including VAX/VMS and IBM System/370 mainframes. Howard's work was also the first to disprove the prevalent belief that Lempel-Ziv encoded files could not be further compressed. Additional compression could be achieved by performing a Huffman Squeeze on the LZW data, and Howard's version of ARC was the first program to demonstrate this property. This hybrid technique was later used in several other compression schemes by Phil Katz and others.

Later, Phil Katz developed his own shareware utilities, PKARC and PKXARC, to create archive files and extract their contents. These files worked with the archive file format used by ARC, and were significantly faster than ARC on the IBM-PC platform due to selective assembly-language coding. Unlike SEA, which combined archive creation and archive file extraction in a single program, Katz divided these functions among two separate utilities, reducing the amount of memory needed to run them. PKARC also allowed the creation of self-extracting archives, which could unpack themselves without requiring an external file extraction utility.

Following the System Enhancement Associates, Inc. vs PKWARE Inc. and Phillip W. Katz lawsuit, SEA withdrew from the shareware market and developed ARC+Plus.[2] This version included a full-screen user interface, with the last known version being 7.12.[3] SEA was eventually sold to a Japanese company[who?] in 1992.[citation needed]

The ARC format is no longer common on PC desktops but most antivirus scanners can still uncompress any ARC archives found in order to detect viruses within the compressed files.
Katz left Allen-Bradley in 1986 to work for Graysoft, a Milwaukee-based software company. At the time, he had worked on an alternative to Thom Henderson's ARC, named PKARC. ARC was written in C, with the source code available on System Enhancement Associates' BBS. PKARC, written partially in assembly language, was much faster. Katz had a special flair for optimizing code. Besides writing critical code in assembly language, he would write C code to perform the same task in several different ways and then examine the compiler output to see which produced the most efficient assembly code. He initially publicly released only PKXARC, an extraction program, as freeware. Its much greater speed caused it to spread very quickly throughout the BBS community. Strong positive feedback and encouragement from the community prompted Katz to first add his compression program, PKARC, and eventually to make his software shareware. In 1986 he founded PKWARE, Inc., while the company's operations were done in his home in Glendale, Wisconsin,[2] but Katz did not leave Graysoft until 1987. Steve Burg, a former Graysoft programmer, joined PKWARE in 1988.

Early years

Rad Group was founded by brothers Yehuda (born 1942) and Zohar (born 1949), in Tel Aviv, Israel. Both brothers studied electronics engineering at the Technion – Israel Institute of Technology. Yehuda started his career in the 1960s working for Motorola Israel but in 1973 decided to start his own business importing and distributing computer networking equipment, a company called Bitcom. Later Yehuda parted company with his initial business partner and started a new company Bynet. The company’s main business was distributing Codex Corporation’s products, the company soon became a market leader in Israel. In 1977 Codex Corporation was acquired by Motorola, but due to its success Bynet maintain the distribution rights for its products; however in 1981 Motorola decided not to renew the distribution agreement with Bynet and sell the former Codex Corporation’s in Israel directly.[1]


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