Im all ears.....LOL.  You got a tool to break it down?

Good Opcode breakdown here....

http://www.thealmightyguru.com/Games/Hacking/Wiki/index.php?title=6502_Opcodes

Found my answers....

http://www.paladingrp.com/brianb/rom_hacks/ikari.html

Understood.

I was actually doing some reading and saw where several authors have revised code withing the ROM data to allow certain games to save high scores.  Being Im an old techie from way back, and have dabbled in plenty of coding for chipsets, I wanted to have a look at the code on the eeprom.  Using a generic eeprom editor I was able to open and look at the data on chip 1D (the chip that holds the info for save game stuff) and make a simple compare of an altered chip vs a stock chip.  I can see where the date was changed to allow the "save game" info, unfortunately without the opcode list or instruction set, I can not decypher the code.

A snipit of code that looks like this

Code:

$000060,06 20 AD 07 20 A0 74 AD 07 20 99 00 66 C8 D0 F7
$000070,A9 02 8D 16 40 A0 05 B9 BA 66 99 D7 07 88 10 F7
$000080,20 74 92 AD 78 07 09 80 20 A5 91 4C 8B 80 01 A5

could easily be interpreted with the correct opcode set.

06 20 AD could mean branch to address 20AD or it could mean a hundred different things. 

LOL...long story short, I was just trying to find an instruction set for that particular Eeprom so I could poke a round a little.

Thanks,

ANSWERS BELOW!

1. What power supply should I use?  It needs to be a switching power supply that provides a -5v correct?

Here is the pinout:

http://www.arcade-museum.com/pinouts-game/8895.html

You need +5 and +12. The +24 shown is for the coin counter. Not needed. You do not need -5. I would personally find a working original power supply. But, since you are making the harness, you can use any old arcade type switching power supply.

This is a good middle of the road power supply:
http://na.suzohapp.com/all_catalogs/power_supplies/80-0064-00

2. Where is a good resource to purchase eeproms and PPUs in case I want to change games in the future?

I buy both of these on ebay. 2764 eeproms are easy to find on ebay for cheap. You will need to hunt for the PPUs and buy the kits on ebay with the PPU you want.

3. I have an eeprom burner and eraser.  Are MAME roms the exact copy of the original arcade games assuming I choose to download and burn the eeproms myself?

Yes, I use MAME roms. They are dumps from the arcade eeproms. Same thing.

4. Is there a way to burn the PPUs?

NEGATIVE.

You say 2764 eeproms?  Is that an intel chip?  Would you know where I can get a data sheet or at minimum the opcodes associated with the chip?

Thanks,

Hello,
I am in the process of gathering all my pieces for my nintendo build.  I have built a few multi game jammas but I want this one to be a VS dual system cabinet which is new to me.  I know there are some differences with the VS system games and i think I am up to speed on a lot of it.  I have read and watched all of Johns tech articles and videos which have helped immensely.  This is my current setup..

1 VS system mother board populated with SMB and Excitebike eeproms and PPUs
2 nintendo color inverter/amp boards
2 19" vision pro CGA LCD monitors
2 edge connectors and wire for the harness
1 mame joystick / button kit

I am going to build the VS harness from scratch and wire everything in as usual.

A few questions that I need assistance with...

1. What power supply should I use?  It needs to be a switching power supply that provides a -5v correct?
2. Where is a good resource to purchase eeproms and PPUs in case I want to change games in the future?
3. I have an eeprom burner and eraser.  Are MAME roms the exact copy of the original arcade games assuming I choose to download and burn the eeproms myself?
4. Is there a way to burn the PPUs?

If you have any other info I may not be considering as I build this first VS game please let me know.

Thanks,
Jimmie

on that website.

Sorry iankellogg, I meant where can I download entire games images (all 6 eeproms).

http://www.scoresaves.com/

Sweet, thanks.  Where can I download the ROMs?

New here so dont bash me, but...............where can I get the high score eeproms?  Better yet, where can I get the files to burn them myself?  I have an eeprome writer so it may make more sense to do it that way.

Great score!.....my best is only 1.35m.

I have never seen that PCB before so I am not sure where you could find that information.

I have been looking up more information on the sync fix stuff but i still have to do some more research.

So I ended up going with the original nintendo vid converter/amp board (seen above) and a 19" Vision Pro LCD monitor that accepts a CGA input.  This way I do not need to purchase a cga -> VGA converter.

Next stop......assembly.

Edge connectors, wire, vid/amp board, and monitor should be here next week.  This will give me some time to get the cabinet assembly going.

if you use a proper monitor then it should in theory sync. but i have been burned in the past and not every monitor can sync to the weird vsync pulse.


The multi game boards don't have a converter at all, they generate the signals directly so they are doing it with proper vblanking

Here is a schematic that has video inversion as well as a simple 2W audio amp

Thanks again.

I have found a couple of these inverter/amp boards for sale.  They are original nintendo AV-01 boards and I am hopeful they may work better than the aftermarket boards.  They were like $15 each.



You wouldn't happen to know or where I could find the pin outs for this would you?

Thanks,

I can probably upload a schematic for both the inverter, audio amp and sync when i get home.

So a lot of games including nintendo games had a sync signal where the hsync pulses continue through the vblank. This allowed the monitors to maintain sync during vblank without needing a PLL circuit. The cheapy LCD converters do not like that and look for a solid long vblank pulse. So what you need to do is somehow break up the composite sync into its Hsync and Vsync components. and then recombine them in such a way that the Vblank doesn't have hsync pulses.

Awesome, thank you iankellogg....a schematic would be great.

I do know that whatever on-board converter they use on the jamma multi game boards seems to work very well.  I have no issues with any of my multi game cabinets and they all use LCD flat panels.  I assume you have read unfavorible reviews regarding these converters when used with unisystem boards?

Also, what if I were to use the Vision Pro monitors that accept a CGA 9 pin hookup to eliminate the need for the CGA->VGA converter?

I have not had the best of luck getting those cheapy LCD adapters to sync on nintendo boards. I haven't tried the vs. but i assume its the same .

You will have to invert the video as you said. but not the sync. as the sync is proper negative sync.


https://www.mikesarcade.com/cgi-bin/store.pl?sku=VS2JAMMA This will invert the video and provide audio amplification but I don't believe it fixes the sync issue also it only allows you to play half the gameboard at a time, as you have noted.

If you were motivated enough you could build your own adapter, or beg someone to do it.
Technical of how that needs to be done:
 Need to break out both game outputs/inputs.
 Need to seperate the sync out to vsync/hsync and recombine to vsync with proper vblanking to allow sync of cheapy LCD adapter
 Dual audio amps.

Thanks iankellogg.

I am fairly tech savvy and pretty good with the iron, so i am confident in my building skills.  I have already purchased the edge connectors to make the harness off the unisystem board myself so I have that part covered.  If you could elaborate a bit on the comment:

"seperate the sync out to vsync/hsync and recombine to vsync with proper vblanking to allow sync of cheapy LCD adapter"

I am not an expert in video signals but I am pretty sure if you point me to a build example or to someone/someplace who can explain it in detail, I think I could do it myself.

I was eyeing up two of these boards to fix the inverted color issue, then feeding the output of those into a cga to vga adapters to feed the flat screens.  If you think this will not work, I will need to explore different options.

Thanks,
Jimmie

[BOTH]

Hey guys, new to the group. 

I am building my first custom unisystem arcade.  I have built several successful jamma cabinets but I am a long time lover of SMB, excitebike, goonies, etc.  I have a VS unisystem board with SMB and Excitebike on it and I want to build a dual monitor cabinet with LCD panels to display and play the 2 games.

So I understand these these boards (obviously) can display 2 games at the same time, but they output inverted colors and unamplified audio.  So I need to do the following:

- Invert the colors for BOTH game video outputs AND convert that output from CGA to VGA so I can use LCD/LED flat panels.
- Amplify the audio

Is there an all in one adapter to do this?  I have found some adapters that will do one side of the board to allow one game to be converted, but not both.

Am I thinking this through correctly?  Any suggestions?