Pins 19 (X) and 16 (Y) control video inversion. There is no
way to control them via software unless you want to mod the
board. Asteroids only uses pin 19 to invert *BOTH* X and Y.
Very early asteroids boards did not have any video inversion support.
Cocktail is implemented by looping back the P2out signal which is
tied to the Bank RAMSEL circuit when Player 2 is active.
DLX upright mirror cabinet will ground pin 19 (X), which has the
affect of inverting both X and Y when an asteroids board is plugged
in to a DLX upright mirror cabinet (which leaves it with
the Y backwards in reference to the mirror). Hope that helps.
FWIW, I ran some proto adapters a few weeks ago that are
pure plug and play for ast/dlx including video inversion
circuit, audio amp impedance matching (AR vs. ARI/II), and
input signals swapped. I have not had anytime to test
out the audio stuff yet, but the X flip and input swaps
works fine. I myself have only a DLX cabinet and having
a plug and play way to change boards will be a great helper.
Now that I'm back from vacation hopefully I'll have some
time to catch up on arcade things again. My kids are wearing
me out, glad they will be returning to school!
-Scott
Mark Shostak wrote:
> Good deduction; I have a cabaret.
>
> Two comments:
>
> 1 - With regard to your problem, it doesn't sound like a side effect of the
> s/w changes, nor your wiring changes. I would start by putting the original
> roms back in, and see if you still have the problem.
>
> 2 - Some of the games used jumpers on the edge connector to configure the
> inverters. I don't recall if A/AD does, but a quick look at the schematics
> would answer that. If so, it's a h/w problem.
>
> If the inverters are controlled by s/w, it wouldn't take a rocket scientist
> to add a line or two to properly initialize the inverters for the appropriate
> cabinet type. Check out the schematics and let us know, then we'll be
> more motivated to give you a patch to try. :-)
>
> -Mark
>
> P.S. Scott B. is probably the premier Asteroids/AD expert these days,
> he may be able to tell you off the top of his head, followed by Neil...
>
>
>
> On Sun, Apr 02, 2006 at 01:52:07PM -0500, joemagiera wrote:
>
>>This is a screwy problem, and it's screwy to describle, but it's driving me
>>crazy, so please bear with me, I'll describe it as best I can.
>>
>>I'm running Asteroids in a standard Asteroids Deluxe upright. I'm using the
>>ROMs hacked by Mark Shostak as mentioned here:
>>http://www.ionpool.net/arcade/asteroids/asteroids_mod.txt. These hacked
>>ROMs fix everything except the inverted image as Asteroids Deluxe uses the
>>mirror. (FYI, Mark's ROMs will work without further modification in an
>>Asteroids Deluxe cabaret as that doesn't use a mirror). To fix the mirror
>>inverted image problem, I swaped the red & blue wires running from the
>>monitor deflection board to the yoke.
>>
>>My problem is that the game will randomly switch the image to upside down.
>>That is upside down when you're looking at the corrected inverted image on
>>an AD cabinet. It doesn't happen often, it happened 3 times yesterday
>>during a 5 hour game party, once in the middle of a game. It's hard to trap
>>on a pic, but here's an attempt:
>>
>>---------------------------------------------------------------------------
>>** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
>>** Please direct other questions, comments, or problems to chris@westnet.com
>
> ---------------------------------------------------------------------------
> ** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
> ** Please direct other questions, comments, or problems to chris@westnet.com
---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Sun Apr 2 19:13:06 2006
This archive was generated by hypermail 2.1.8 : Tue Apr 04 2006 - 08:50:01 EDT