Jump to content
IGNORED

Haunted House glitch on 7800


Lord Innit
 Share

Recommended Posts

I've searched the forums and web but cannot find any mention of this problem. I have two Haunted House (PAL) carts and a PAL 7800. Both carts glitch when booted up. The pair of eyes appear on the left side of the screen while the rest of the graphics display normally. As you know, they should start on the right side. When you start a game you can move around but your eyes are still out of position with the rest of the screen so basically is out of sync when colliding into walls. Is this a known problem with the game on the 7800? Both carts work fine on my light sixer.

Link to comment
Share on other sites

Interesting...First time I've ever read about someone having issues with a Haunted House cartridge. I suspect that the issue may be related to (a missing) timing (circuit). Curious, do you have a 2600 Dark Chambers cartridge, and does it the play okay or not?

 

Additionally, the same exact issue plagues the Atari 2600 driver, for both NTSC and PAL, under the MAME emulator:

 

post-18-0-94867600-1442347087_thumb.pngpost-18-0-02416800-1442347089_thumb.png

 

Haunted House for either region behaves the same way you describe. The opened bug report provides the following further details:

 

"All issued traced to either initial change of the new 6502 core or the IRQ fixes shortly after"

 

The above bug report info, coupled with knowledge we have of the missing timing circuit impacting the 2600 version of Dark Chambers for some revisions of the motherboard, means that if indeed, the issue is associated with timing, there may not be an easy fix (I.E. without some hardware modification(s)) for allowing your PAL 7800 to play the actual cartridge as intended.

 

It would be great though for someone with a little more tech knowledge form a hardware and/or emulation perspective to chime in with their thoughts.

 

In the meantime, do you have a 2600 Harmony cartridge? If so, does it play Haunted House without problems?

Link to comment
Share on other sites

My presumption was wrong. Thankfully, a certain genius 7800basic developer was able to get to the root cause:

 

"Reading a write-only register on most 2600s returns the last value on the bus, and the last value on the bus is the last byte in the opcode.

The HH programmer made a typo. At $F44F the game is sutracting using the value in $0f, instead of subtracting using the literal value $0f. Since the last byte of the opcode is $0f, most 2600s will pull this value and wind up working as intended. But on 1 out of 100 2600s, the "last value on the bus" result doesn't happen. Same is true for emulators that don't similarly handle reads from write-only registers.
I've attached a hacked version of the HH bin which corrects the instruction at $F44F, and it runs as expected in MESS[/MAME].
The 7800 has the same bus effects in places too, BTW."
In other words, your console is fine, Lord Innit. It just responds differently to this particular programming bug.
Here's the fixed Haunted House binary, thanks to the same source :)
EDIT: See this post below.
  • Like 2
Link to comment
Share on other sites

Cheers for the info I really appreciate it. I'll play that fixed ROM once I get myself a Harmony cart. :)

 

Realizing you're across the pond...you are probably going to want the PAL fixed ROM instead of the previous provided NTSC one.

 

It has been graciously provided from the same previous source :-D :

 

Haunted House (Atari) (PAL) badread fix.zip

 

For posterity's and clarity sake here is the NTSC fixed ROM again, utilizing the same naming convention above:

 

Haunted House (Atari) (NTSC) badread fix.zip

Link to comment
Share on other sites

Realizing you're across the pond...you are probably going to want the PAL fixed ROM instead of the previous provided NTSC one.

 

It has been graciously provided from the same previous source :-D :

 

attachicon.gifHaunted House (Atari) (PAL) badread fix.zip

 

For posterity's and clarity sake here is the NTSC fixed ROM again, utilizing the same naming convention above:

 

attachicon.gifHaunted House (Atari) (NTSC) badread fix.zip

Downloaded both thanks :) I'm looking at getting an AV modded NTSC 7800 in the near future.
Link to comment
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...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...