6520 PIA?

[+Larry]

In doing some testing, I have found two different versions of the 6520 PIA. These are CO14795 and CO14795-12. I have not looked extensively, but I've only found the versions without the "-12" in 600XLs. Maybe also in 1200XLs? Does anyone know the difference(s)? Were there any other versions that anyone has seen?

 

-Larry

[+Stephen]

This is just a guess, but the second number is usually the speed of the chip. I have a bad PIA which I pulled from an 800 (stuck bit), and it is has three rows of numbers.

R6520AP

R6520-13

8209 (then a Fuji symbol)

[Marius]

In a few of my 65XE PAL and 800XE PAL there is not a 6520 but a 68B21 ...

 

That is another type PIA with same functionality and one or two options more, which are not used/connected on atari I guess.

[thorfdbg]

In a few of my 65XE PAL and 800XE PAL there is not a 6520 but a 68B21 ...

 

That is another type PIA with same functionality and one or two options more, which are not used/connected on atari I guess.

No, from the datasheet it's really a functional equivalent of the PIA, just originally designed for the 6800 and not the 6502, and from another vendor. There are no additional functions, registers or anything.

[drac030]

In a few of my 65XE PAL and 800XE PAL there is not a 6520 but a 68B21 ...

 

What part number does it have?

[Marius]

Unfortunately my atari's are all closed with screws at the moment. I don't know which of the stock has the 68b21 ... I know a few of my xe computers have that pia. When I found one I will post part number ... But isn't that info yet available somewhere?

[Marsupilami]

Some of my PAL 800XL are CO14795-12 (here), a few are CO14795 (here), same thing for SECAM and NTCS. IMHO it's just the rev. or part number.

More pictures here : http://atarinside.dyndns.org/

Edited August 13, 2013 by Marsupilami

[sup8pdct]

i have been told a long time ago thar the 6x21 has an extra buffer on the 2 8bit ports so it can drive more loads. otherwise they are the same.

[thorfdbg]

i have been told a long time ago thar the 6x21 has an extra buffer on the 2 8bit ports so it can drive more loads. otherwise they are the same.

 

Not as far as I'm reading the spec. It's the same old PIA, one port is buffered, the other is open collector. I unfortunately forgot which one is which, though.