Editing Hayes Microcomputer Products (section)

==Hayes '302==
In June 1983, Hayes and a number of other manufacturers were sent licensing demands by a smaller modem manufacturer, BizComp,<ref>{{cite magazine |magazine=InfoWorld |date=10 October 1983 |title=BizComp's patent could raise retail price of modems |first=John |last=Markoff |page=1 |url=https://books.google.com/books?id=1i8EAAAAMBAJ&pg=PA1}}</ref> who had filed a patent in 1980 but only received it in 1983.<ref>{{cite patent
| country	= US
| number	= 4387440
| status	= Expired
| title		= Modem control device code multiplexing
| pubdate	= 
| gdate		= 7 June 1983
| fdate		= 3 March 1980 
| pridate	= 
| inventor	= Michael Eaton
| invent1	= 
| invent2	= 
| assign1	= Business Computer Corp
| assign2	= 
| class		= 
| url		= https://patents.google.com/patent/US4387440A
}}</ref> The patent covered the use of an escape sequence to switch between command and data mode, just like the Smartmodem. BizComp had already implemented the system in its modems in 1980, a year before the Smartmodem came to market. They offered a sliding scale of terms; an outright license was $2 million, but they would accept as little as $500,000 with additional per-unit fees. Hayes responded by licensing the patent outright for $2 million ({{inflation|US-GDP|2000000|1983|fmt=eq|r=-3}}).

Hayes themselves also had a patent filing working its way through the system since 1981, although it mentioned the escape system and modes only in passing. Having obtained a license, they re-wrote their patent to include a lengthy section on the idea of a guard time, which the original Bizcomp patent lacked. They received the patent, 4,549,302 ''Modem With Improved Escape Sequence With Guard Time Mechanism'', in October 1985.<ref>{{cite patent
| country	= US
| number	= 4549302
| status	= Expired
| title		= Modem with improved escape sequence mechanism to prevent escape in response to random occurrence of escape character in transmitted data
| pubdate	= 
| gdate		= 22 October 1985
| fdate		= 11 October 1983
| pridate	= 
| inventor	= Dale Heatherington
| invent1	= 
| invent2	= 
| assign1	= Hayes Microcomputer Products
| assign2	= Telogy Networks
| class		= 
| url		= https://patents.google.com/patent/US4549302A
}}</ref>

Hayes began sending bills to other manufacturers, charging 2% of the retail price per modem<ref name=king/> that followed the Hayes system, including those modems that had already been built and sold. This resulted in a number of companies launching a patent review, claiming the concept had long been used in the industry. A flurry of suits and countersuits followed. The bid to overturn the patent failed in 1986.<ref name=king>{{cite magazine |magazine=Computerworld |url=https://books.google.com/books?id=U6-CLZCsUSoC&pg=PA94 |page=94 |title=Can firms fight 'jungle king'? |first=James |last=Martin |date=15 December 1986}}</ref> Some time later, Hayes received permission to bring suits in federal court against infringers, and filed an initial suit against several major manufacturers, Everex, Ven-Tel, Omnitel and [[Prometheus Products]].<ref>{{cite magazine |title=Brief Notes |magazine=Computerworld |url=https://books.google.com/books?id=hq4deM8-L3wC&pg=PA113 |page=113 |date=20 November 1989}}</ref>

Competitors derisively termed it the "modem tax", and a number of manufacturers banded together and introduced the [[Time Independent Escape Sequence]], or TIES, but it was not as robust as Heatherington's system and never became very successful.