I heard different between the broken joint venture between Nintendo and Sony.
Well, apparently, it was nearly a done deal, when Nintendo had a change of heart after closely charting the process of the flopped CD add-ons for the Mega drive, aka Mega cd/32x. Hence, Nintendo thought it wouldn't be such a good idea as it would most likely flop, as 'most' add-ons do

. So Nintendo pulled the plug, and Sony went on with their plans.