Yes, I was talking about Z8000. Amazing processors (Z8001 and Z8002), but Zilog took too long to clean the bugs. That, and the lack of retrocompatibilty sealed its fate and Motorola 68k took over.
Zilog tried again and again (Z80000, Z180 with Hitachi, Z280, Z380...) but never recovered.
I have two Z380 waiting for the completion of its motherboards... :-)
And, then, they thought: "hum... let's do our 16 bits microprocessor... and forgot the retro compatibility with our own 8bit chip!".
What could go wrong?