Digging into ancient microchips (with hot sulfuric acid)
Wednesday, September 22, 2010
6502 vs. 6507
Many sites mention something to the effect of, "The 6507 is just a 6502 in a smaller package." Well, not quite. The two are almost identical, but the 6507D from our Atari 2600 system has a slightly different metal layer. Metal is used to make the last digit of the on-die part number, so it's an easy change from "6502" to "6507" Also, the 6507 has its NMI and IRQ pads permanently hooked up to the +5V supply. This disables both flavors of interrupt in the 6507.
MOS 6502 rev D and 6507 rev D die labels
Difference in metal layer between MOS 6502 and 6507