Replacement PIA

[xrbrevin]

Hi,

In case anyone needs to know, I found a cheap drop-in replacement for the PIA:

 

https://www.ebay.co.uk/itm/2pcs-MC6821P-MC6821-Peripheral-Interface-Adapters-DIP-40/281278693561

 

I needed one and it arrived today - plugged it in and the Atari is now working fine!

[+tf_hh]

Hi,

In case anyone needs to know, I found a cheap drop-in replacement for the PIA:

 

https://www.ebay.co.uk/itm/2pcs-MC6821P-MC6821-Peripheral-Interface-Adapters-DIP-40/281278693561

 

I needed one and it arrived today - plugged it in and the Atari is now working fine!

 

You should do some extensive tests... the 6821 is only specified for 1 MHz clock. The 2 MHz version as needed for the Atari 8-Bit series is 68B21. Of course a lot of chips would work flawless with "overclocking", but... it might be show any sideeffects at any time.

[xrbrevin]

hmmm, interesting point but it seems ok thus far.

the 68B21 is also very cheap so i think i'll get a couple just in case

cheers!

[Level42]

Meh....it’s like engines today, change a few bits and you have 20 horse powers more....

[Mathy]

Hello Andre

 

You're forgetting something: Those engines are often built with the higher performance in mind, but tuned down for economic and marketing reasons. And they've been doing that for decades already.

 

ICs are more like floppies. They try to make as many as they can in as good a condition as possible. After production they are tested. The good ones are sold as "fast" or "higher capacity", those that are tested as "not that good" are sold as "slower" or "lower capacity".

 

Meaning most engines can be tuned for better performance, because they can handle it, most ICs can not be run faster, because they are just not that good.

 

Sincerely

 

Mathy