Sure.
The simplest way, is to develop your 8-track-to-stereo mix on the 688, per normal procedures, assuming you know the basic operation of the 688. Then, cable the mix/output busses (usually Pgm Buss 1 & 2) to the standard computer soundcard's Line-Input, using an RCA-to-1/8"-stereo Y-cable adapter.
You'll need a recording program that records from the soundcard's Line-In to 16-bit/44.1kHz/stereo WAV format files, (PC). You'll also need CD burning software, that will allow you to lay the WAV files out into songlists, and burn audio CD's.
This is the simplest method that yields CDs of your stereo mixes from a Portastudio.
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A more sophisticated method would involve porting the individual tracks from the 688 into an 8-input audio interface to the 'puter multitracking software in discrete 8-track format, for further mixing "in the box".
That's a whole other post.
