My Star Castle machine is a Rockola version of the game. The Schematics and the two boards are exactly the same as the Cine version with the exception that the CCPU actually says "Rockola" in copper on the top side. It uses ribbons, like I said, it's exactly the same. I have never seen a Rockola CCPU with an edge connector. Are you sure about that? Why would Rockola use an edge-connector design like Sega in a Space Wars type game and then go back to the original albiet more mature version of Cine monitor, CCPU, and audio board used in Star Castle?
Regarding Sega Space Ship being a variant of Cine Space Wars, are you saying that there was a Rockola Space Wars? I'd love to see that.
William Boucher
----- Original Message -----
From: Mark Shostak
To: vectorlist@vectorlist.org
Sent: Sunday, January 10, 2010 7:27 PM
Subject: VECTOR: Troubleshooting Sega Space Ship (Space Wars Clone)
> Hi everyone.
> My name is Fabrice. I'm 36 years old, living in France.
> I just subscribed to this list.
> I'm currently trying to repair a SEGA vector PCB.
> Game is called "Space Ship" and is an exact clone
> of Cinematronics's Space Wars.
Fabrice,
For reference, this board is an implementation of what we refer to as the "CCPU" (Cinematronics CPU).
Interesting. The board looks very similar to Rockola's CCPU implementation. Rockola also used a large edge connector in place of individual connectors. Cinematronics licensed this design to Rockola and apparently Sega as well. When I get time, I'll find out if it's coincidence they both use the edge connector or if the Sega design is descended from Rockola.
> There is no output sent to the X-Y screen.
That's normal (for a faulty CCPU).
> My oscilloscope says that the /RESET signal is periodically fired.
That's also normal (in a faulty CCPU). In the Cinematronics implementation, they use that signal to light a fault LED.
> I understand all the meaning of the word "difficult" when it applies to the CCPU troubleshooting ! ;-)
It can be difficult, but it's a matter of understanding the system and applying the right methodology. I've been repairing those boards for 15 years, and you get the hang of it.
> I can seen important glitches on some of the E14 PROM data bits.
This is what we call a red herring. This is _not_ your problem.
At 2uS/div, your DSO may not be sampling fast enough to catch the complete transition to the opposite logic state, before the next transition begins. Remember, you're looking at the inside of a 5MHz CPU. Try 50ns/div or better and see how it looks.
You mentioned there were glitches, but didn't mention if the device contents were correct. If the contents are wrong, then I'd agree the part has a problem.
That said, there are some weird artifacts (transitions) on the output of E14, and you'll find they are coincident with similar transitions on the inputs of the device. Most of those output signals are driving combinatorial logic, which isn't bothered by this behavior; when the signal stabilizes, so does the entire chain. However, if you're seeing glitches, for example, on the output of F14, which drives _registered_ logic, that would be a problem. Regardless, this is normal behavior for E14.
> Does anyone know if its a normal behavior for this chip ?
Yes, see above.
> Maybe address bus is changed on clock's raising edge and data bits
> are used on clock's falling edge... In this case, it would be OK.
Again, not your problem.
If you really want to test the prom devices, the best way for you to do so, is:
1) Substitution
2) Data contents validation (if subs aren't available)
Signature Analysis would be the first choice, but it doesn't appear your board will easily lend itself to that methodology.
FWIW, I've never seen a prom in a CCPU that didn't work, but did have valid contents. Therefore, if you validate contents, the probability is very high that the device is good. Further, PROM failures on the CCPU do happen, but are statistically very rare. I base this on having repaired hundreds of these boards.
I'd offer to fix your board (see cinelabs.com), but you indicated you'd like to fix it yourself. My advice would be to not do what many other people have done, which is to take a shot-gun approach, which makes the board look like a mine field, and frequently introduces more problems than it fixes.
Hope that answers some of your questions.
au revoir,
-Mark
P.S. I renamed your thread, so people searching for information about Space Ship can tell what this thread is about.
P.P.S. Is your control panel missing buttons? Space Wars has 10 buttons, used to start the game. I see them on the game flyer, but not in the picture of your actual game.
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Received on Sun Jan 10 19:51:19 2010
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