There has been a disgusting trend among PC makers to make everything "multimedia." Unfortunately, the industry's concept of music includes only playback of commercially produced "media content," with the result that the OEM sound cards in many new machines do not include an audio input jack. The input jack has been omitted to make room for output jacks for up to 7 or more channels of speakers.

Even adding a new "super sound card" is often not, by itself, a real solution to the problem, since the audio input is essentially an old fashioned serial port, and may conflict internally with other devices.

Old-timers may recognize the problem of finding DMA and IRQ assignments that don't conflict with other installed devices. There has been no progress in expanding the number of DMA channels and/or IRQ interrupt assignments available since the original DOS days. Although PnP in recent Windows versions usually is pretty good at resolving conflicts, in this case (adding another serial port device) it appears to fail pretty generally.

An additional caution for those contemplating new machines is that some, especially laptops, do not have any external parallel ports, and the only serial port may be the mouse connector. Sellers often are quite lax about telling you exactly what ports one might expect are or are not there.

IF THE MACHINE IN QUESTION has an audio jack, it would usually be the appropriate place to connect from the earphone jack of an external player. The output from the earphone jack is audio, and the simple serial cable isn't going to add any significant noise.

For machines that don't have an audio jack, a common workaround is to use the mouse port (which is a serial port with a different connector, but converison cables should be readily available) and, if necessary, use a USB mouse (which should also be readily available) to free up the serial (mouse) channel. Sometimes this works.

John