>Seems unlikely, as the 6503 through 6507 are 28-pin chips, while >the 6502 is a 40-pin chip. More likely the legend is smudged so >that the 2 looks like a 3, or it's a typo. I clarified this on my post on April 2nd under this topic. The 6503 is part of a longer custom part number. It is infact a 65c02. - Paul