Re: [stella] Difference between 6507 and 6502

["Mark Graybill" <saundby@xxxxxxxxxxxx>]

Or, rather, the same as the 6502 in an AppleII, Atari 800, or Vic-20. The chip in the C-64 is the 6510, which has some additional I/O on-chip. As I recall, the 6508, 6509, and 6510 are a later core that is basically the 6502 core with additional I/O or address lines, depending on which version you get (the 6509 could address 1MB, the others both had additional I/O as I recall, and all three of these could go tri-state using the AEC input. The 8501, 8502, and 8502 cores are practically identical to the 6508-10.

 

The versions of the original 6502 core were, as I recall, the 6502-7, and the 6512-15. The 6502 and the 6512 were the 40-pin versions, the others were all 28-pin. The 28-pin versions all had different combinations of pins brought out, and the only difference I recall between the 6502 and the 6512 was that the 6502 had an on-chip oscillator and the 6512 didn't (as was true of all the 651X versions except the later 6510, which was either/or.)

 

I'm going by memory here, I'm sure there's more info at 6502.org.

 

-Mark G.

----- Original Message -----

From: Roger Williams

To: stella@xxxxxxxxxxx

Sent: Tuesday, December 17, 2002 4:49 PM

Subject: Re: [stella] Difference between 6507 and 6502

 

Can anyone tell the difference between a 6507 and a 6502 apart from the missing pins? Are both cores 100% identical including any non documented opcodes?

Yes, they are identical.  The 6507 package was created strictly

to save space on the PCB, in those days it did not make sense

to create a new die and mask for such an "improvement" since this

was much more expensive than the package design.  The 6507 in

a 2600 should react the same way to undocumented opcodes as the

6502 in a C64.

 

--Roger Williams