Those discmans were great. Ramstorage memory to buffer the audio datastream for a few hundred milliseconds or even a few seconds.
One would suspect that the data temporarily stored would be the 2x 16 bit data (2 channel for stereo) since 16 bit memory is readily available and cheap in price.
However, if it is an Application Specific Integrated Circuit (ASIC), it could also have been a 1 bit fifo that is just clocked in and out at the right samplerate*2 channel* 16 bit data + encoding stuff. The raw datastream from the laser and photodiode pickup. To be passed on to the decoding logic circuitry.
Either 16 bit parallel DAC or a 1 bit PCM DAC running at several megaHertz with a cheap simple Low Pass Filter be damned...
All that for the joy of never experiencing a skipping discman and disastrous moments of silence when it is subject to mechanical vibration. Marketed as : Anti-shock, Shock proof. It was wonderful and bliss all over.