Re: New to the list

Hi all, hi William.

Thanks a lot for your detailled answer.
Yesterday, just before registering to the list, I did a lot of searches
in the list archive.
I did found the http://www.biltronix.com/ link and some interresting
informations on the CCPU (Exorciser...).

> Be aware that a factory original copy is not necessarily a great copy.

That's what you just made me understand...
I thought quality was lost during scanning process, but in fact
pdf document is close to the original document.
Your VB scan will help me on some drawings. Some chips references/pins
are less unreadable on your document than on the Cine doc.

> I would offer to repair your CCPU but if it is a copy made by Sega or
> whomever, then I wouldn't know if the circuitry is actually all the same
> or not.

Up to now, I found only 1 single difference between SEGA's design
and Cine's design.
SEGA is using 8 x 4-bits PROMs (MB7054, HM7643) where Cine is using
2 or 4 chips.
SEGA is refering its chips from "IC001" to "IC151" and Cine is using
line/column location. But same chips are sitting on same place on PCB.
For example, Cine's chip B12 (74LS10) is called "IC113" by SEGA and
sits on the same place (close to a corner).

I want to try to repair this PCB by myself and I think I have enough
skills at leat not to damage it more.
Maybe once I'll have taken 1 kg aspirine I'll go back to you. :-)
But SEGA did not put sockets at D8 & U14 for an Exorciser use !

> Is the monitor in the game using the digital ribbon cable
> input? Is there a digital to analog converter board in between the CCPU
> and a monitor that has an analog input? Just wondering. If the CCPU
> circuitry is identical, then I should be able to repair it if it should
> ever come to that.

There is no ribbon cable between the game PCB and the monitor.
There are about 30 small individual wires tied together which is
allmost the same.
SEGA's monitor has exacly the same inputs & schematics as Cine's.
There are two DAC80-CBI-V ceramic DAC chips, one LF13331
analog switches, etc...
CCPU is also driving beam brightness & intensity.
Differences are on transistors references.
SEGA uses japaneese semiconductors such as "2SD424" & "2SB554"
for example for last stage of deflexion amp.

Some picts can be seen here (PCB & monitor) :
http://www.gamoover.net/Forums/index.php?topic=20677.0

> The MMI 6331 is a standard bipolar prom and works the same as other
> similar parts such as 74S288 or 82S123 made by other manufacturers. The
> data outputs are valid any time the /G pin is active (low). There's no
> clock input, just the enable input.

Yep. SEGA's MMI6331 PROMs are always selected : pin 15 (/CS) is always
grounded.
I'm just surprised to see switching glitches on some data bits.
When *1* single address bit changes (all other remain the same),
I can see transient glitches on some data bits which should remain
unaffected by this single address change due to PROM content.

Regards,

Fab

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Received on Sun Jan 10 07:22:23 2010