AY-3-891x Sound Chips: Pin Assignment Differences?

[jaybird3rd]

In a post in another thread, I mentioned the Intellivision Computer Adaptor that I repaired earlier this year, and it reminded me of a question that I've had about it:

 

We all know that the Computer Adaptor adds an extra 2K of RAM to the Intellivision console, along with an extra sound chip (the same one used in the console) for extra voices and controller inputs. But, it turns out that this sound chip isn't exactly the same as the one used in the console: the chip in all of my consoles is the AY-3-8914, while the one in the Computer Adaptor is the AY-3-8917.

 

I'm having a problem with the controller ports in my Computer Adaptor which makes me think that this chip needs to be replaced (I don't think the problem is related to the repairs I did; it appeared some time later). I socketed the 8917 chip and have tried replacing it with a few known-good 8914 chips, but the sound/controllers don't work at all with an 8914 installed. I've also tried the 8917 in my consoles instead of the 8914, with the same results. This leads me to believe that the two chips are not entirely pin-compatible. I've collected information and data sheets on the AY-3-891x series in an attempt to confirm this, but I haven't been able to find much information that is specific to the 8917. Does anyone here happen to know what is different between these two chips? Is replacing an 8917 with an 8914 simply a matter of rearranging some of the pins, or are there other differences that make this impossible?

 

Thanks in advance!

[JamesD]

Every AY chip with a different number has a different pinout.

Search for AY-3-8917 Datasheet and AY-3-8914 Datasheet.

The datasheets should have the pinouts.

Edited May 18, 2010 by JamesD

[jaybird3rd]

Thanks, that's good to know. The various wikis and blogs that I consulted gave me the impression that the pinouts were the same.

 

I still haven't found any datasheets specific to the 8917, although I've found plenty for the other variations (perhaps I'm not searching in the right places). I'll keep looking.

[JamesD]

Well, some of the models have different memory maps for the registers as well but I'm not sure about those.