Zilog Z280
An enhanced version of the {Zilog Z80} with a 16 bit
architecture, introduced in July, 1987. It added an {MMU} to
expand addressing to 16Mb, features for {multitasking}, a 256
byte {cache}, and a huge number of new {op code}s (giving a
total of over 2000!). Its internal clock runs at 2 or 4 times
the external clock (e.g. a 16MHz CPU with a 4MHz bus).
(1994-10-31)