Re: Troubleshooting Sega Space Ship (Space Wars Clone)

Bill,

Sorry to be a prick, but, let's stay on topic. This thread is about
troubleshooting. Feel free to post academic items in the original thread, or
start a new one. Better still, if you want to question me, do it in private
mail. Please don't raise the noise floor to where people can't follow the
thread.

> I have never seen a Rockola CCPU with an edge connector.

Are you implying you've seen every board they've made? Remind me again, how
long have you been doing this?

> Are you sure about that?

Yes. See above.

> Regarding Sega Space Ship being a variant of Cine Space Wars, are you
saying that there was a Rockola Space Wars?

No. All I said was that Rockola had a CCPU that used a single edge connector
in a similar or possibly even identical configuration, and wondered if it
was coincidence. There were no implied messages.

Thanks,
-Mark

On Sun, Jan 10, 2010 at 6:51 PM, William Boucher <boucher@mnsi.net> wrote:

> 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 <shostakmark@gmail.com>
> *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 20:29:45 2010