Williams questions? Ic's, Harnesses & Test Bench Setup.

Thomas

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Williams questions? Ic's, Harnesses & Test Bench Setup.

1) I want to pull the trigger on the most used Williams chips for Stargate, Defender, Robotron ect... ect...

What are those chips??? So I may have a decent stock of them here at home.

Whats the difference between say SN7474N and 74LS74? Will both these work?

When getting the regulators for the linear power supplies would LM723CN work?

2) If I build a test bench just for the older classics can I use 1 harness?

Defender is certainly different.

3) I have a new stargate main harness with both power supplies harnesses. Aka switcher and linear.

Can I use the switcher harness from a stargate with a defender main harness?

No matter what I do I cannot get access to test the ram on my defender with it in the cab. I am seriously considering pulling everything out of the defender and nailing up on the wall. I already have my stargate boards hanging on the wall so this is not a big jump.

I just haven't tried to hookup a test bench for the williams games yet. Figured I would ask some questions in the hopes of heading off some issues.

At this time I only have stargate and defender boards sets to work on here at the house.

Thanks for your time in advance
 
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He was also asking to substitute an 'LS' for the standard, but otherwise yes I think we're in heated agreement.
grin.gif


Part substitution must take into account the circuit where it's used. I've seen designs that have used a standard or 'S' part where an 'LS' would have done fine. I think in general you can substitute like so, from left to right:

74S74 => 7474 => 74LS74

But not right to left! In any case it's important to understand the circuit well enough to make sure the substitution will be fast and strong enough.
grin.gif

This quote seems to answer one question...

http://forums.arcade-museum.com/showthread.php?t=69724&highlight=7474+74LS74
 
You should be able to use your Stargate test rig for a Defender board set, the 4 main headers are the same (MPU board power, Video out, Sound power and ROM power). I use the same harness for all my bench testing.

It just doesn't use the same I/O connection for each game, but I test that by going into the switch diagnostic screen and then grounding each pin one at a time to see if the message lights up.

ken
 
No matter what I do I cannot get access to test the ram on my defender with it in the cab. I am seriously considering pulling everything out of the defender and nailing up on the wall.
What tests are you trying to do with the RAM? I didn't have any trouble accessing mine for probing and swapping with the back door off .. just curious what's giving you trouble. I would suggest a small footstool (or similar) if you need to set down test equipment inside.

LeChuck
 
Billy,

Defender
Stargate
Robotron
Joust
Bubbles
Splat

All use the same power section of the harness as well as video, sound. The coin door and control panel sections is where they are different.

The answer to your question is Yes, you can use one harness to test the above listed Williams games.
 
I built a Williams to JAMMA adapter that you are welcome to borrow if it will help.

Man that would be perfect! If you could take some close up pictures and post them up that would be off the hook! I might not even to need to borrow it. It could be just what I need to get this project off the ground.

We have been working today to clear out a wall for free space to hang the boards on.
 
Billy,

Defender
Stargate
Robotron
Joust
Bubbles
Splat

All use the same power section of the harness as well as video, sound. The coin door and control panel sections is where they are different.

The answer to your question is Yes, you can use one harness to test the above listed Williams games.

That's awesome Dave I just hate to use your pretty stargate harness for a test rig. You should sell a test rig harnesses for those williams games. I wonder how many would sell? Hint hint... I would certainly buy one!

Your atari harness has saved / diagnosed my pole position twice and its still up and running great because of it.
 
I am in Leonardtown, might be easier if I just give it to you! :)

I know man your right down the street from riptor & my girls work. I could have her stop by any evening next week and pick it up. She works in Valley Lee weekdays 8 to 5.
 
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That's awesome Dave I just hate to use your pretty stargate harness for a test rig. You should sell a test rig harnesses for those williams games. I wonder how many would sell? Hint hint... I would certainly buy one!

Your atari harness has saved / diagnosed my pole position twice and its still up and running great because of it.

Yeah sure, add another project to my ever expanding list of things to get done.:eek:

I keep running out of hours in a day to get anything productive done. The Wife has said that she is going to put up my "white board" again. Apparently it helped keep me focused on the proper order of projects.
 
A white board certainly would help me. Sorry bout the dreaming...
 
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