We went through all this a couple of years back under the same heading. If the Z235980 at 234 THz is code compatible then, if I understand you correctly, it IS a Z80, right? Even though the Z180 won't fit in a Z80 socket, you'd sell it as a Z80 anyway, right? Even though it didn't even exist back when it mattered, you still insist it's a Z80, right? My Pentium executes the Z80 code just fine at about 75x the speed of of a Z80. Does that mean it's a Z-80? We're comparing CHIPS, not philosophical constructs. If it IS a Z80, or Mostek 3480, or something else EXACTLY a Z80, i.e. built under the license, pin-compatible, code-compatible, etc. then MAYBE it's germane to this discussion. No chip that isn't a pin-compatible substitute commonly referred to as a Z80 back in the days when the Z80 mattered is germane to this topic. If it won't plug into the socket of a Z80, FORGET IT, because it's not a Z80. If that's too difficult for you, then please ask an adult why a 47-ohm resistor isn't the same thing as a 75-ohm resistor. I'm sure glad you're not trying to sell parts any more, Allison. I'd hate to have to argue with you that the choke you're trying to pitch isn't a diode. Dick ----- Original Message ----- From: "ajp166" <ajp166(a)bellatlantic.net> To: <classiccmp(a)classiccmp.org> Sent: Friday, December 21, 2001 4:24 PM Subject: Re: 6502/Z80 speed comparison (was MITS 2SIO serial chip?)