Jump to content
Sign in to follow this  
Ramses

Atari 800XL Memory Problem

Recommended Posts

10 minutes ago, hueyjones70 said:

I am working on a 800XL that doesn't go to self test when I boot while pressing OPTION. Any ideas of the possible cause.

Does it go to self-test when you type BYE from BASIC? If not, then look at a bad PIA or PIA socket.

Share this post


Link to post
Share on other sites

It went to self-test when I typed BYE. I ran the memory test and everything was green. I rebooted with OPTION pressed and it went to self test like it should.  I decided to let it run the self test continuously for a while.

Share this post


Link to post
Share on other sites
27 minutes ago, hueyjones70 said:

I rebooted with OPTION pressed and it went to self test like it should. 

You probably have dirty contacts in the OPTION key switch if it works intermittently.

  • Like 4

Share this post


Link to post
Share on other sites

I don't think the problem is with the keyboard, I used two different keyboards with similar results. Also, sometimes when I press the OPTION key I get random letters and characters displayed on the screen.

Share this post


Link to post
Share on other sites
1 hour ago, hueyjones70 said:

I don't think the problem is with the keyboard, I used two different keyboards with similar results. Also, sometimes when I press the OPTION key I get random letters and characters displayed on the screen.

Could be an issue with your GTIA and/or its socket.

Share this post


Link to post
Share on other sites

Couldn't the problem also possibly be with the socket for the keyboard's ribbon cable?  Maybe loose pins?  Just a thought.

  • Like 1

Share this post


Link to post
Share on other sites
On 11/30/2019 at 12:06 PM, hueyjones70 said:

I am working on a 800XL that doesn't go to self test when I boot while pressing OPTION. Any ideas of the possible cause.

Mine does the same. The OPTION key works fine. Typing BYE works fine, and the computer seems to have no issues. Just won't boot into test mode when pushing OPTION.

Weird. Looking forward to the replies.

Share this post


Link to post
Share on other sites

Do these machines have an original OS ROM?

 

When you do get into self test via "BYE" from BASIC, do the start/select/option keys seem a little less responsive in they keyboard test that you would expect? Does pressing one of them generate a solid or intermittent tone?

Share this post


Link to post
Share on other sites

I tried with an original ROM and one of the dual OS EPROMS. Same results. When I got in with BYE the keys all worked OK for a few tries. I am going to switch out the GTIA and maybe the PIA if nothing shows up there I will run the SALT diagnostic.

Share this post


Link to post
Share on other sites
27 minutes ago, Nezgar said:

Do these machines have an original OS ROM?

 

When you do get into self test via "BYE" from BASIC, do the start/select/option keys seem a little less responsive in they keyboard test that you would expect? Does pressing one of them generate a solid or intermittent tone?

I spent a few hours on the weekend restoring this machine, one thing I did was to completely strip back the keyboard and give it a very good clean. All keys are very responsive.

 

I don't think it's been taken apart before, so I'm assuming the ROM is original.

 

Edited by nama

Share this post


Link to post
Share on other sites

As hueyjones70 mentioned. If I first test the memory with 'BYE' then reset out, and then press 'OPTION' it seems to work...go figure????

Edited by nama

Share this post


Link to post
Share on other sites

I have switched out the large chips and the MMU and the problem persists.  Sometimes when I boot I don't get any noise and sometimes I don't get a ready prompt and on those occasions the computer doesn't respond to any commands.

  • Confused 1

Share this post


Link to post
Share on other sites

I finally figured out what was wrong, I had installed xx256 memory chips so I could do a Wiztronics memory upgrade and one of the chips was bad.

  • 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.

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...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...