ComStar SVD Owner’s Manual
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parity setting, as this is the most common difference among
systems. You should normally use 8 data bits, NO parity, and 1
stop bit (8, NONE, 1). The second most common setting is 7 data
bits, EVEN parity, and 1 stop bit (7, EVEN, 1).
Your modem doesn’t seem to be compressing the data.
The compression features are on by default, but check the
following:
Your software needs to use a streaming protocol, such as
Ymodem-G or Zmodem. Xmodem and Ymodem are not
adequate for compression.
Your software must be set up so that your modem is using
hardware flow control (RTS/CTS ON).
To get maximum data throughput, you can use a
computer-to-modem speed of 115,200 bps (if your COM port can
support this speed); set this for each entry in the dialing directory.
Be aware that many files downloaded from bulletin boards have
already been compressed. In general, your modem will not be
able to further compress such files.
Voice/Speakerphone Troubleshooting
You can’t talk with the person at the other end while
transferring files.
The other party doesn’t have an AudioSpan-compatible SVD
modem. Not all SVD and DSVD (Digital Simultaneous Voice and
Data) modems are compatible with each other.
The quality of the voice messages needs to be improved.
Voice quality is related to the number of bits per sample that are
saved on your hard disk. Many voice applications use two bits per
sample as the default setting. Some applications allow you to
increase the number of bits per sample to three or four to
improve the quality.
Keep in mind that increasing the bits per sample increases the
amount of disk space each voice message consumes. A ten-
second message taken at 7200 samples per second and two bits
