Jump to content
OldAtAtari

Zarlor Mercenary doesn't work on my Lynx II

Recommended Posts

Hi, everyone. I think my Lynx II has a Zarlor allergy.

 

Zarlor Mercenary will not play through the official cartridge, and it also won't play on my El Cheapo, even though I've tried ROMs that are verified to work.

 

As for my official cartridge games, I have the following, with Zarlor being the only non-functional one:

California Games

Electrocop

Klax

Todd's Adventures in Slime World

Warbirds

Batman Returns

Bill and Ted

Paperboy

Roadblasters

Zarlor Mercenary


Has anyone ever experienced such a thing, where a game will not work, either with the original cartridge or with a ROM? My guess is that I have a bad address in my RAM, and maybe Zarlor is trying to reference that address, whereas maybe other games do not.

Any other ideas?

Thanks.

Share this post


Link to post
Share on other sites

Good news... I've found that if I'm playing the ROM through the El Cheapo flash cart, the game crashes just as the second title screen/demo is starting. If I quickly press the A button just as that screen is starting, it sometimes bypasses that sequence and takes me into the game, making it playable. When I play Zarlor from the official Zarlor cartridge, it doesn't get that far, so I don't have the option of pressing A.

 

So what I'm thinking about now is how to edit the ROM to remove that second title screen/demo, to bypass it automatically.

 

I'm at a loss there... I thought it would be possible by taking the ROM into a hex editor and poking around in there with various tweaks until I find a spot that's creating the sequence I want to bypass. But no matter what I do in that file, it just breaks the ROM. I was expecting that a simple tweak, like turning an A1 into an A2, might change the color of something, or the number of lives, or whatever, but apparently it doesn't work like that. I suppose I have to see if I can find a disassembler to break this down into assembly code. It's still a long shot, but then maybe I could find the right hack to do the job.

Any thoughts are appreciated.

Share this post


Link to post
Share on other sites

That's an interesting idea.

 

I have a similar problem with California Games... I can't get by the spinning license plate without the game freezing.  I didn't think of trying a rom hack.  It seems you and I are both having an issue on the same screen (the animated screen after the initial graphic)- in my case Zarlor Mercenary works fine.

 

I need to look at some of the programming resources and see what the SDK imposes as these two loading screens seem to be common on all commercial Lynx games.  It might not be possible to jump straight to the interactive screen as the problematic screen might be responsible for loading data.  If nothing special is happing there, we might be able to bypass.  Handy emulator would speed up the process.

 

So strange we are experiencing this... I could see it being a romcart issue, but I'm also seeing the problem with my original cart.  It has to be a hardware glitch that has manifested over time (my unit used to play California Games just fine).

Edited by Bstar

Share this post


Link to post
Share on other sites
28 minutes ago, Bstar said:

That's an interesting idea.

 

I have a similar problem with California Games... I can't get by the spinning license plate without the game freezing.  I didn't think of trying a rom hack.  It seems you and I are both having an issue on the same screen (the animated screen after the initial graphic)- in my case Zarlor Mercenary works fine.

 

I need to look at some of the programming resources and see what the SDK imposes as these two loading screens seem to be common on all commercial Lynx games.  It might not be possible to jump straight to the interactive screen as the problematic screen might be responsible for loading data.  If nothing special is happing there, we might be able to bypass.  Handy emulator would speed up the process.

 

So strange we are experiencing this... I could see it being a romcart issue, but I'm also seeing the problem with my original cart.  It has to be a hardware glitch that has manifested over time (my unit used to play California Games just fine).

Wow! Someone else has this same problem! That's comforting.

Hacking the game certainly isn't turning out to be as simple as I had hoped, but I'm not giving up yet. I've accidentally hijacked a topic in the Lynx Programming forum. Really, I didn't mean to take it over, but there are some folks over in that topic talking about this now.

New 6502 (and successors) disassembler - Atari Lynx Programming - AtariAge Forums

Edited by OldAtAtari

Share this post


Link to post
Share on other sites

I'm going to see if I can get the debug env going this weekend and see if I can figure anything out.  Definitely a bit out of my comfort zone programming-wise, but I might be able to make a little progress.

  • Like 1

Share this post


Link to post
Share on other sites
5 minutes ago, Bstar said:

I'm going to see if I can get the debug env going this weekend and see if I can figure anything out.  Definitely a bit out of my comfort zone programming-wise, but I might be able to make a little progress.

Good luck to you! Please let me know if you figure anything out, and I'll let you know if I figure anything out!

Share this post


Link to post
Share on other sites
On 1/29/2021 at 6:50 PM, OldAtAtari said:

Bstar, you had a good idea to make a YouTube video of your California Games problem. So now I've done the same thing!

YouTube Video of the Problem

I think it's a ram issue.  I had my first random crash playing Toki (near the end of the second level in the water).  The Diagnostics rom does not seem to test memory addresses so I'd really like to find a utility that does that.  That still doesn't explain the incredible coincidence you and I are having, but I can't think of anything other than memory that could cause this.

 

I have a dead Lynx 1... if that has the same memory as my Lynx 2 and is something I can transfer, I might try that. 

Edited by Bstar
  • Like 1

Share this post


Link to post
Share on other sites
13 minutes ago, Bstar said:

I think it's a ram issue.  I had my first random crash playing Toki (near the end of the second level in the water).  The Diagnostics rom does not seem to test memory addresses so I'd really like to find a utility that does that.  That still doesn't explain the incredible coincidence you and I are having, but I can't think of anything other than memory that could cause this.

 

I have a dead Lynx 1... if that has the same memory as my Lynx 2 and is something I can transfer, I might try that. 

I agree. A RAM problem is the only thing I can think of. Maybe there's a bad sector of RAM, and certain games (Zarlor and California Games, and maybe Toki) try to access it while others do not.

The diagnostics cart was disappointing. When you test the system, it just says "Passed!" I would really like to know what it's checking.

Share this post


Link to post
Share on other sites

I'm going to transfer my memory chips from my lynx 1, hopefully this weekend.  I'll report on how that turns out.  The memory is different, but exact same specs it seems.

Share this post


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

I'm going to transfer my memory chips from my lynx 1, hopefully this weekend.  I'll report on how that turns out.  The memory is different, but exact same specs it seems.

You are a braver man than I. Please let me know how it goes!

Share this post


Link to post
Share on other sites
On 2/3/2021 at 11:53 PM, Bstar said:

I'm going to transfer my memory chips from my lynx 1, hopefully this weekend.  I'll report on how that turns out.  The memory is different, but exact same specs it seems.

Why? These RAM chips are not rare. I bought a bag of these chips from ebay for less that $5. Much easier than transplanting chips.

Share this post


Link to post
Share on other sites
20 minutes ago, karri said:

Why? These RAM chips are not rare. I bought a bag of these chips from ebay for less that $5. Much easier than transplanting chips.

 

Karri, it's the HY53C464LS-10? It's good to see that it isn't a surface mount.

 

image.thumb.png.8cc252c4225044927722190401222fed.png

Share this post


Link to post
Share on other sites
41 minutes ago, karri said:

Is it a pretty easy soldering job? I did the power regulation mod on mine, plus the cap replacement. Is replacing a ram chip any more difficult than those jobs?

Share this post


Link to post
Share on other sites

I'll still let Bstar try it first if he still wants to. 🙂 But I wouldn't mind having a few of those chips on-hand.

Edited by OldAtAtari

Share this post


Link to post
Share on other sites

And Karri, what do you think of this theory of bad RAM being the cause of our problems with California Games and Zarlor Mercenary? Is there something more likely that we're not considering?

Share this post


Link to post
Share on other sites
On 2/5/2021 at 11:31 PM, OldAtAtari said:

And Karri, what do you think of this theory of bad RAM being the cause of our problems with California Games and Zarlor Mercenary? Is there something more likely that we're not considering?

Extremely unlikely. If there is anything at all wrong with the RAM the decryption of the cart will fail and you get INSERT CART.

 

My guess is that either one of the system chips has a flaw. As the flaw occurs at a certain point in graphics my guess is Suzy.

Share this post


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

Extremely unlikely. If there is anything at all wrong with the RAM the decryption of the cart will fail and you get INSERT CART.

 

My guess is that either one of the system chips has a flaw. As the flaw occurs at a certain point in graphics my guess is Suzy.

Thank you, Karri. That's a bummer for Suzy. Hopefully it won't affect any more games.

Share this post


Link to post
Share on other sites

Ahh, wish I saw the rest of this thread on Friday, lol.  Anyway, I have a dead Lynx 1, so desoldering the 2 ram chips was trivial.  Problem I'm having now is getting the shielding off my Lynx II and I'm pretty close to giving up on it.  Definitely feel like I might damage things at this point.

 

Karri, you are much more knowledgeable on this than I am, but I thought replacing the ram would be a good start.  Do you think transplanting the Suzy chip is a better bet (can a Lynx 1 Suzy be transported to a Lynx II)?  I'm not finding a good photo diagram that shows which chip that is, but I'm assuming it's one of the ones that will be ridiculously hard to solder.  I can reflow the chips with the small contacts, but I don't have the right equipment to do a transplant.

Share this post


Link to post
Share on other sites

On a side note, I think I might order a cap replacement kit since I have everything apart.  At least I'll get something useful done.

Share this post


Link to post
Share on other sites

Just replacing chips at random is not a good idea. Perhaps we need Lynx repairing instructions for diagnosing the troubles. All the info is in the forum already, you just need to find the correct pages. We could set up a Wiki about this at the AtariGamer site. It might be the best way to share information.

  • Like 1

Share this post


Link to post
Share on other sites
8 hours ago, karri said:

Just replacing chips at random is not a good idea. Perhaps we need Lynx repairing instructions for diagnosing the troubles. All the info is in the forum already, you just need to find the correct pages. We could set up a Wiki about this at the AtariGamer site. It might be the best way to share information.

Brilliant idea, karri. These machines are pretty old now, and repairing them might become an essential skill for all of us soon.

Share this post


Link to post
Share on other sites
12 hours ago, Bstar said:

On a side note, I think I might order a cap replacement kit since I have everything apart.  At least I'll get something useful done.

Bstar, I was able to replace the caps on mine without too much issue. I did the power regulation circuit too, which was more difficult, but doable. While I was in there, I also did the USB power cord mod at cap 41, which was really easy, and has been amazing since I can run my Lynx with a 5V power bank, or with an extension USB cord, I can use a 5V wall charger. https://atarigamer.com/articles/adding-a-micro-usb-power-socket-to-an-atari-lynx
I didn't do the thing in those instructions with the little USB port. I just ran the other end of the USB cord out through the battery compartment, and it just hangs there waiting to be plugged into a power source.

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...