Zookeeper working but not working

mjenison

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Hi all,

My pain-in-the-ass Zookeeper is acting up again.

This time, the game appears to run fine. However, the animals tend to teleport around. For example, on the first screen, when the elephant climbs the right side, when it reaches the top, it rapidly teleports to the left side of the screen (you can see a blur of it as it moves).

All self tests pass, though I don't know how thorough the self tests are.

Any thoughts on where to look?
 
Hi all,

My pain-in-the-ass Zookeeper is acting up again.

This time, the game appears to run fine. However, the animals tend to teleport around. For example, on the first screen, when the elephant climbs the right side, when it reaches the top, it rapidly teleports to the left side of the screen (you can see a blur of it as it moves).

All self tests pass, though I don't know how thorough the self tests are.

Any thoughts on where to look?
I actually saw that game. I've been wondering in the intervening last 10.5 years if you ever finished it. you were changing it to 4164 ram if I recall.

I'm not familiar with what I consider Taito's rendition of Williams hardware, but there's a whole board for video processing that's supposed to run its own 6809 and the manual talks about all the different clocks generated there. https://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Zoo Keeper.pdf (page 22)

https://web.archive.org/web/20170616062012/https://quarterarcade.com/taitos-qix-hardware-and-games (Video Processor)

I'm guessing the CPU board can reach this for tests cause I see the 32 4116 rams but maybe the 2114 and 2148s aren't part of the test procedure. or what I'm thinking is it's probably a timing issue. I haven't looked at Qix or anything close to this schematics in years but I would venture the 20 MHz crystal passes through a bunch of 74LS74s and from what I know on Williams games those can go bad. I've never seen teleporting stuff in those though.

it's too bad I don't live there anymore I would like to help out if I could.
 
I'm not familiar with what I consider Taito's rendition of Williams hardware,
Clearly, since anyone who is actually familiar with that hardware knows that that the sound circuit is the only thing that looks like "Williams".

I'm guessing the CPU board can reach this for tests cause I see the 32 4116 rams but maybe the 2114 and 2148s aren't part of the test procedure.
Or you could actually read the manual and see what's tested:

1747343068589.png


Any thoughts on where to look?

I'd start with the the crap around the U3/U4 RAMs that are shared between the 2 CPUs.

The self test routines (probably) test each CPU's ability to access that ram and minimally tests passing data across it, but probably doesn't really beat on it.
The 2 6809s run 180 out of phase so there shouldn't be any contention between accesses, but if the clock generation at U25 is glitchy, all bets are off.
 
Update: Fixed!

I had already replaced the socket at U3, so I decided to replace the socket at U4 as well. I swapped in another set of known working 2114 RAMS as well.

The animals no longer teleport to the left side when they reach the top of the right side.

Seems like @HudsonArcade was right about the 2114 RAM tests not being exhaustive tests.
 
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