Hayes Microcomputer Products
Hayes Microcomputer Products was a US-based manufacturer of modems. The company is known for the Smartmodem, which introduced a control language for operating the functions of the modem via the serial interface, in contrast to manual operation with front-panel switches. This smart modem approach dramatically simplified and automated operation. Today almost all modems use a variant of the Hayes AT command set.
Hayes was a major brand in the modem market from the introduction of the original 300 bit/s Smartmodem in 1981. They remained a major vendor throughout the 1980s, periodically introducing models with higher throughput. Their competition through this period was primarily from two other high-end vendors, USRobotics and Telebit, while other companies mostly sold into niches or were strictly low-end offerings.
In the early 1990s a number of greatly cost-reduced high-performance modems were released by competitors, notably the SupraFAXModem 14400 in 1992, which eroded price points in the market. Hayes was never able to respond effectively. The widespread introduction of ADSL and cable modems in the mid-1990s repeatedly drove the company in Chapter 11 protection before being liquidated in 1999.
Before Hayes
left the Georgia Institute of Technology in the mid-1970s to work at an early data communications company, National Data Corporation, a company that, among its many businesses, handled electronic money transfers and credit card authorizations. Hayes' job was to set up modem connections for NDC's customers.Hayes also worked for a time at Financial Data Sciences, which sold automated teller machines to the savings and loan market, modifying machines sold by larger companies to large banks with the branding of the smaller S&L. From this company, he learned the value of selling into niche markets the larger players ignored.
Hayes was a computer hobbyist, and felt that modems would be highly compelling to users of the new 8-bit computers that would soon be known as home computers. However, existing modems were simply too expensive and difficult to use or be practical for most users. He felt that this market was likely to be ignored by the larger modem vendors like IBM.
Early Hayes products
At the time, modems generally came in two versions, external modems using an acoustic coupler for connection, and direct-connection modems used with minicomputers or mainframes. Acoustic couplers were entirely manual; the user picked up the phone's handset, dialed manually, and then pressed the handset into the coupler if a carrier frequency was heard. Disconnecting at the end of the session was also manual, with the user lifting the handset out of the coupler and hanging it up on the phone body in order to depress the hook switch and return the phone to the on-hook state and end the call. This was a straightforward and thus a popular solution; the Novation CAT was a popular modem of this type.Internal modems had the advantage that they could use the computer bus not only to exchange data between the computer and the modem, but command and status information as well. This allowed them to control the entire connection cycle, dialing the phone to start, and hanging up at the end. Such systems were available for large machines, especially the mainframes used by banks which had to automatically dial their branches for end-of-day updates. None of these systems were available for microcomputers, and Hayes' initial concept was to offer similar products into this market.
Hayes started producing such a system in his kitchen in April 1977 with his friend and co-worker, Dale Heatherington. Their first product was the 80-103A, a 300 bit/s Bell 103-compatible design for S-100 bus machines. At this time, it was illegal to connect any non-Bell hardware to the telephone network, so the 80-103A was designed to connect to a Bell-supplied Data Access Arrangement which the user rented for a monthly fee. To fill in dead-times in the modem sales, they also took on part work doing electronics assembly for other companies.
Business picked up quickly, and by January 1978 they had quit their jobs at National Data to form their own company, D.C. Hayes Associates. In its first year, the new company sold $125,000 worth of product.
Sales further improved in early 1979 with the introduction of the 300 bit/s Micromodem 100 for S-100 bus computers and the Micromodem II for the Apple II.
As a result of Bell having lost several key lawsuits related to the connection of unlicensed equipment to its telephone network, by 1978 it finally became legal to connect any FCC-approved system to the Bell network. To comply, Micromodems were supplied their own DAA-like connector in the form of the FCC-approved "microcoupler": a small external box that connected to the internal modem card using a ribbon cable.
In 1980, the company changed its name to Hayes Microcomputer Products.
The Smartmodem
Although powerful, the internal modem was commercially impractical. Not only did it require special driver software that often meant it could only be used with a single terminal emulator, but a different hardware design was needed for every computer bus, including Apple II, S-100, TRS-80, and others. As modems became popular, users on these platforms began asking for designs as well.A solution to the cross-platform connection was to use the RS-232 serial port instead of the internal data bus; modems were serial devices in the end, and most computers included an RS-232 port or some variant. The trick would be how to send commands over the same connection as the data. A few external modems already offered the ability to dial the phone by entering a phone number when the modem was first started, based on the idea that it could not be connected to a remote system when first powered up, so anything sent from the computer could be interpreted as a command. The problem was sending a command to hang up, while the modem was already connected. There needed to be some way to indicate that the characters flowing out from the computer to the modem were not simply additional data to be sent to the far end, but commands to be acted on.
Hayes and the company's marketing manager Glenn Sirkis approached Heatherington with an outline for a new command-driven external modem. Several solutions to the command problem were studied, and in the end, Heatherington decided the only practical one was to have the modem operate in two modes. In one, data mode, all data forwarded from the computer was modulated and sent over the connected telephone line as it was with any other modem. In the other, command mode, data forwarded from the computer would be interpreted as commands. In this way, the modem could be instructed by the computer to perform various operations, such as hang up the phone or dial a number. The modem would normally start up in command mode.
The problem was how to move from mode to mode. One option would be to signal this using one of the many pins in the RS-232 cable. However, while the 25-pin connector on the modem side had more than enough pins for this purpose, the computer side often had far fewer pins connected and controllable, if it even used a full 25-pin connector at all. In fact, there were very few pins that were guaranteed to work on all computers, mostly the data in and out, "ready" indications that said whether the modem or computer was operational, and sometimes flow-control pins. While it would have been possible to use some of these pins for the sort of command-switching they needed, this may not have been universally supported across all machines.
Heatherington instead came up with the idea of using a rarely seen sequence of characters for this duty. Since these characters could be sent to the modem using the same two data pins that the port would need anyway, they could be sure that such a system would work on every computer. The sequence he decided on was . When this was received from the computer, the modem would switch from data to command mode. Of course, it was possible that the computer would send this sequence for other reasons, for example, the sequence is contained within the text on this page, and likely would be in any document referring to modems. In order to filter out these "accidental" sequences, Heatherington's design only switched to command mode if the sequence was led and followed by a one-second pause, the guard time, in which no other data was sent. In this case it could be safely assumed that the sequence was being sent deliberately by a user, as opposed to being buried in the middle of a data stream.
With the basic idea outlined, Hayes and Sirkis gave Heatherington the go-ahead to build a prototype by adding a microcontroller to an otherwise lightly modified version of their existing 300 bit/s hardware. Sirkis was particularly interested in using the 1 MHz PIC microcontrollers, which were available for only US$1 a piece. After six months of trying to get the modem working with the PIC, Heatherington gave up and demanded they use the 8 MHz Zilog Z8 instead, a US$10 part. Sirkis acquiesced, and a working prototype was soon complete.
Hayes added a requirement of his own, that the modem be able to automatically detect what speed the computer's serial port was set to when first powered on. This was not simple unless the modem "knew" what data were initially being sent, allowing it to time the bits and thereby guess the speed. Heatherington eventually suggested the use of a well-known character sequence for this purpose, recommending for "attention", which is prefixed on all commands.
The new design, housed in an extruded aluminum case sized to allow a standard desktop telephone to rest on top, was announced in April 1981. It was known simply as the Smartmodem. The Smartmodem was the first modem integrating complete control over the phone line, and that allowed it to be used in exactly the same fashion with any computer.
Hayes originally had big plans for the form factor, referring to it as the Hayes Stack and intending to release a range of products that could be stacked beside the computer. In the end, only two non-modem devices were added to the line. The Hayes Stack Chronograph, an external real-time clock and the Transet 1000, a printer buffer and primitive email box. Both of these items' sales were apparently dismal. Early advertising referred to the Smartmodem as the "Hayes Stack Smartmodem", but this naming convention was dropped a short time later.
At the time of its introduction, the modem market was fairly small, and competitors generally ignored the Smartmodem. But it was not long before hobbyists were able to combine the Smartmodem with new software to create the first real bulletin board systems, which created significant market demand. The market grew rapidly in the mid-1980s, and as the Smartmodem was the only truly "universal" modem on the market, Hayes grew to take over much of the market. By 1982, the company was selling 140,000 modems a year, with sales of $12 million annually.
Heatherington retired from what was then a large company in 1984.