Jump to content
thomas3120

Quick question on chip A5 pin 11 on a 5200

Recommended Posts

Posted (edited)

Hello,

Just received an Atari 5200 which is in excellent shape including mainboard.

I'm planning on doing the UAV mod to it.

RF shields were in place and appears that no modifications have been done.

I noticed chip A5 (GTIA)? had pin 11 lifted.  Was wondering if this is something Atari did at factory.

It's a 2 port model C021376 REV. 1

Here is the picture:

1288422962_Atari5200Pin11ofA5.thumb.jpg.bede1c39ad50d3ca4f18517fa511d031.jpg

Edited by thomas3120

Share this post


Link to post
Share on other sites

Yep, that's a normal factory modification on a 2-port.

  • Like 1

Share this post


Link to post
Share on other sites
On 1/9/2022 at 3:08 PM, x=usr(1536) said:

Yep, that's a normal factory modification on a 2-port.

Thanks for the reply!

Just wanted to make sure.

Share this post


Link to post
Share on other sites

I've seen that several times on 2 port units, but I've also seen it inserted with the rest of the pins on some 2 port units also and not seen any differences in behavior either way.

 

Share this post


Link to post
Share on other sites

I believe that pin is "Trigger 3".  On the 8-bit computers, the GTIA uses 3 of the 4 trigger lines as inputs, for the Start, Select, and Option keys.  The 4th trigger is an output, and makes the (annoying as hell IMHO) keyclick noise.  It can also be used to create a 4th digital channel for volume only music.  If you've ever played the game Night Mission Pinball, all the sounds are created with the GTIA.  I'm not sure why it would not be used on the 5200.

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...