Please start reading here:
http://en.wikipedia.org/wiki/State_machinehttp://en.wikipedia.org/wiki/Programmable_logic_arrayHow the MT15 CPU did use a state machine plus PLAs
for decoding an instruction and for generating the control signals
for ALU, registers, etc:
http://6502.org/users/dieter/mt15b/mt15b_1.htmNow back to the 6502:
http://visual6502.org/wiki/index.php?title=Hanson%27s_Block_Diagramhttp://forum.6502.org/viewtopic.php?f=8&t=2208I hope, all this helps you to understand how the 6502 does it without microcode.
There are some people in this forum who probably can describe you better
and in more a detailed form what happens inside the 6502 than I can, sorry.