Z80 CS

[wepwawet]

I've got a Z80 marked CS

Does this mean Customer Sample?
rare?

[gshv]

I don't think it's a customer sample. The naming convention for old Z80 processors included only processor speed, while the order number also included package type ("C" or "P") and temperature ("S", "E" or "M"). I guess at some point of time Zilog decided to put those letters on their Z80 processors before they switched to different naming convention Z8400 + speed + package + temperature. So, in my opinion "CS" means "Ceramic DIP" and "Standard temperature range". Plastic chips had "PS" stamped on them, which means "Plastic DIP" and "Standard temperature range":

http://www.cpu-world.com/CPUs/Z80/Zilog-Z80A%208400W.html

Gennadiy

[xsecret]

gshv> correct. I noticed the same thing.