AMR Modem Riser » History » Version 1
laforge, 11/06/2021 08:12 AM
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| 3 | h1. AMR Modem Riser |
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| 5 | AMR (Audio/Modem Riser) cards were used towards the end of the "modem days" where the actual analog modem was completley implemented in software, interconnected via a kind of sound card to a telephone jack. |
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| 7 | In certain generations of PCs, the mainboard contained an AC-Link interface to which external codec ICs (ADC/DAC) are attached. To avoid mainboards having to include the [expensive, space-consuming] line interface circuitry on-board, the AMR connector was defined by Intel. This way the AC97 modem codec IC and analog line interface was pushed to an extension card. |
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| 9 | See the AMR specification attached in attachment:amr.pdf for details on the AMR form-factor, as well as attachment:ac97_r23.pdf for the AC97 specification covering the AC-Link interface. |
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| 11 | h3. AMR mechanical connector |
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| 13 | The mechanical connector is a TE connectivity 5650090-7 PCB edge connector: |
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| 15 | !5650090-7_sml.jpg! |
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| 18 | h2. AZTECH MR2800-W |
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| 20 | This is an example of an AC97 codec based modem implemented in the AMR form-factor. In 2021, it is available for purchase form Pollin at https://www.pollin.de/p/amr-modem-aztech-mr2800-w-platine-mit-2a-relais-2-wechsler-700509 |
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| 22 | !I700509.3-AMR-Modem-AZTECH-MR2800-W-Platine-mit-2A-Relais-2-Wechsler.jpg! |
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| 24 | h3. Si3014 + HAMR5603 DAA chipset |
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| 26 | As can be seen on the picture, it consists of a combination of Si3014 and HAMR5603. The data sheet for the Si3014 is available, but for the HAMR5603 we couldn't find it so far. |
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| 28 | It seems like originally the Si3014 was supposed to be paired with a Si3024 (the combination being called Si3038), see attachment:si3038_si3014_si3024_softmodem_ac97.pdf |
