Initially announced in July, the audio/modem riser (AMR) card and the mobile daughtercard (MDC) will combine audio and modem functions, and will remove from the motherboard the analog circuitry for both. Intel will announce completion of the specifications and begin its promotional push for AMR and MDC next week.

A number of early AMR-compliant products will be announced next week, including the RipTide chip set from Rockwell Semiconductor Systems (Newport Beach, Calif.). Volume shipments of AMR systems are not likely until the second half of 1999, said Russ Hampsten, Intel's audio marketing manager.

The AMR and MDC cards are extensions of Intel's AC '97 specification for audio codecs, as well as a cornerstone of Intel's plan to ultimately eliminate the ISA bus.

The new standards include mechanical and pinout specifications for separating the digital and analog circuitry for audio and modems, making the analog portion into a standard codec available on a riser card or, for mobile computers, a daughtercard. Cost savings in AMR systems can run $5 to $10, which is enough to attract the interest of PC OEMs, Hampsten said.

The concept opens up interesting possibilities for modems, where the certification process for different countries can take longer than the lifetime of a motherboard, Hampsten said. Under Intel's scheme, any audio I/O circuitry requiring certification would move to the AMR card, thus leaving an OEM free to build a motherboard with generic modem functions.

"We can effectively get the integration of having a modem on a motherboard," Hampsten said. Eventually, the digital controller could be merged into core logic, resulting in a software modem integrated onto the motherboard, he said.

Modem manufacturers see the integration trend coming, and some, such as Diamond Multimedia Systems Inc., not only embrace the AMR specification, but helped develop it. "The analog modem that we have today is being integrated. The trend is to move to software," said Tom Eichenberg, audio product line manager for Rockwell.

Among the first AMR-compliant parts, Rockwell's RipTide chip set combines audio and modem digital controllers into a single chip and does the same for the audio and modem codecs.

Other AMR-compliant products might be available in time for the Intel Developer Forum, scheduled for Sept. 15-17 in Palm Springs, Calif. "We already have a number of motherboard companies with designs that will be ready at IDF," Hampsten said.

For now, the AMR specification applies only to analog modems. Revisions will incorporate technologies such as digital subscriber lines. "We tried to give the spec as much legs as possible — we reserved six pins for DSL expansion," Hampsten said.

Version 1.0 of the AMR specification has been available on Intel's Web pages since July.

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