To put it into perspective, 64KB of DRAM contains 524288 transistors, as 1 bit of DRAM needs 1 transistor. The 6502 is mid-1970s technology while the 64KB DRAM is early-1980s technology.
Despite having so few transistors, the 6502 is generally viewed as twice as fast or more as the Z80 for the same clock speed[https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/the-cpc-revision-zero-article/msg243843/ Source]. Two reasons can explain it:* The 6502 has an 8-bit ALU while the Z80 has a 4-bit ALU.* The 6502 has a built-in clock doubler circuit built inside , allowing it to perform 1 internal operation and 1 memory access per full-cycle. In contrast, the chipZ80 can only do at most one memory access per M-cycle, which takes 3 to 6 T-states.
The 6502 comes in a 40-pin DIP package. It has been produced by various manufacturers and used in a wide range of applications, from gaming consoles like the [[Atari 2600|Atari VCS]], [[Atari Lynx]], [[Nintendo Entertainment System]] and [[PC-Engine]] to personal computers like the [[Apple II]], [[BBC Micro]], [[Oric]], [[VIC20]] and [[Commodore 64]].