A signed 4-bit number allows for 8 values with a positive/negative sign. CivII had a maximum of seven civs because the barbarians were included in the total. Conversely, CivIII probably doesn't pretend that barbarians are a civ and allows for 8 civs. The "7" in the preview probably referred to the number of AI components.
P.S. No, I have no idea why Firaxis uses bloody 4-bit variables. It's not as if using an unsigned byte would somehow slow down a 166 MHz system.
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Leons Petrazickis (St. Leo)
http://aventine.cf-developer.net/minizigg/
petrazi@sprint.ca