Audio/Capture/Playback Adapters

Item	FRU P/N
Adapter / MicroChannel Computers	34F2787
Adapter / AT-Bus Computers	34F2783

Input and Output Devices.

•  Microphone for input:
   3.5mm mini jack connector / max. 600 Ohms impedance (CARDIOID pickup pattern)  cable length <= 1.8 meters (6 feet) / Open circuit voltage sensitivity level between  -60 (more sensitive) and -80 db (less sensitive).   NOTE: Microphone sensitivity is based on 0db = 1 volt per micro bar.
    More sensitive microphones allow table top use. Less sensitive microphones
    generally require hand-held operation.  Frequency response (frequency curve) depends on desired quality and application.

  Guidelines: 

    Music applications: 20 Hz to 20 KHz 3.5 db
    Speech applications: 50 Hz to 12 KHz 5 db

•  Speakers:
   4-8 ohms Shielded cables with 3.5mm stereo mini jack connectors to plug into the Audio Adapter  and connectors on the other end to match the speakers.
•  Headphones:
   8 ohm minimum / 3.5mm stereo mini jack.
•  Line Input/Output cables:
   Shielded cables with 3.5mm stereo mini jack connectors to plug into the  Audio Adapter with connectors on the other end to match to the other audio equipment
   (typically this will be male RCA jacks or Chinch connectors)

Some IMPORTANT

    The best audio quality (Signal to Noise ratio) from the ACPA may be
    obtained by adhering to the following guidelines:
     a. For optimum performance, place the ACPA as far as possible
        from other adapters.
     b. The computer should have its cover on and secured. All
        unoccupied board slots should have a metal bracket installed.
     c. The cables used with ACPA should be shielded, as short as
        possible (less than 1.8meters (6 ft.)), and not tangled. Attempt
        to place the audio and video cables at maximum distance from
        each other.
     d. Avoid unnecessary plugging and un-plugging connections to the
        ACPA as this tends to degrade the quality of the cable to
        board connection.

Available Diagnostics

From the ACPA-Adapter Diskette, (shipped with the adapter) copy one file (using the command)
>COPY A:\DIAG\ACPADIAG.EXE C:\ACPA to the harddisk

Remove the Diskette from drive A: and change to the C: drive
and the ACPA directory and enter ...
ACPADIAG for basic test or ACPADIAG /A ... for advanced testing.
(The tests should start, guidance is available by screenoutput)

Jumper setting

1.  Microchannel Adapter/A
    No jumper setup is required (the jumper on JPR4 must be as shown).
2.  AT-Bus Adapter  The jumper on JPR6 must be as shown.

Input/Output Address Switch (SW1-ADDR.)

ADDR	10	9	8	7	6	5	4	3
310h *)	On	Off	Off	On	On	On	Off	On
318h	On	Off	Off	On	On	On	Off	Off
330h	On	Off	Off	On	On	Off	Off	On
338h	On	Off	Off	On	On	Off	Off	Off
368h	On	Off	Off	On	Off	Off	On	Off
710h	Off	Off	Off	On	On	On	Off	On
718h	Off	Off	Off	On	On	On	Off	Off
730h	Off	Off	Off	On	On	Off	Off	On
738h	Off	Off	Off	On	On	Off	Off	Off
768h	Off	Off	Off	On	Off	Off	On	Off

Interrupt Jumper (JPR4-INT.)

Int.#	J1	J2	J4
2		X
3 *)	X	X
4			X
5	X		X
6		X	X
7	X	X	X

Features:

•  Uses the Texas Instruments TMS320C25 digital signal processor.
•  (8 KB x 16 static RAM on-board memory.
•  Audio Capture and Playback Adapter/A is compatible with IBM Micro  channel PS/2 computers, while the AT-Bus versions is compatible with  non Micro Channel PS/2 computers.
•  Two independent input channels.
•  Stereo input sampling (line left and right) at 44.1 KHz at 16-bit.
•  Monaural sampling (line right or microphone) at 88.2 KHz at 16-bit.
•  Microphone or line input is software selectable.
•  Microphone gain is software selectable.
•  Two independent output channels can each drive a line in conjunction  with speakers or headphone.
•  Software selectable options allows you to use the internal speaker on  IBM PS/2 Micro Channel computers (Audio Adapter/A only).
•  Audio frequency response is 12 Hz to 24 KHz nominal on the output and  12 Hz to 20 KHz nominal on the input.
•  Power-on calibration assures audio quality.
•  Menu-driven diagnostics let you test the functionality of the board.
•  Four Audio Capture and Playback Adapter boards can be installed in one system.
•  ADF - ID @6E6C assigned by IBM (/A Audio Adapter only).
•  Non Micro Channel Adapter fit in short slot of the Model 25.

Please see the LEGAL  -  Trademark notice.
Feel free - send a   for any BUG on this page found - Thank you.