General Information
Model 743 and Model 744 VME Board Computers
The sections that follow explain the functions of the interfaces.
Audio
input and output, in stereo, with a 16-bit coder-decoder (CODEC) over a frequency range of
25-20,000 Hz. A stereo headphone mini-plug (8 ohms impedance) provides output. The ste-
reo line-in and mono microphone mini-plugs provide input with the HP A4302A Audio
Cable.
The CODEC combines CD quality stereo A/D converters for microphone and line input lev-
els. D/A converters for driving headset and line outputs are used. The input sampling rate and
format are programmable, as are the input gain control (used for software control of record-
ing levels) and output attenuation.
1
A
/
9-pin micro D-sub connector. The output is capable of driving a minimum of 8 ohms. It can
also be used for higher impedance devices with little or no additional distortion.
A voice-quality audio output may be used.
For information on programming for audio, refer to Using the Audio Developer's Kit (B2355-
90069) and the man page audio.
Table 1-14 lists the Model 743 and Model 744 audio specifications.
Table 1-14
Model 743 and Model 744 Audio Specifications
Headphone maximum
output level
Input sensitivity
Programmable input gain
Programmable output
attenuation
Programmable rates
Signal to noise ratio
NOTE:
Audio CD ROMs cannot output to the audio out connector.
1-20
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Model 743 and Model 744 Board Computers provide compact disc-quality audio
-inch mini-jack is used for the speaker out connection. The other audio signals are on a
8
Function
2.75 V pp at 50 ohms
Line in, 2.0 V pp at 47 K ohms microphone, 22 mV
at 1 K ohm
0 to 22.5 dB in 1.5 dB steps
0 to 96 dB in 1.5 dB steps
8, 11.025, 16, 22.05, 32, 44.1, 48 KHz
Headphone, 61 dB
Line in, 61 dB
Microphone, 57 dB
Range