Smash TV and other Midway games on Neo Cab

I've heard that Midway uses some oddball way of video display for their video games (sync differences I believe).
Is this correct? What changs would I need to do to my current Candy Cab?

Lastly, how does this effect the JROK?


Edit: Okay, I read about the JROK on their web page. I guess I only need to know about how it effects my cab.

For Midway stuff all you really need to change is the hsync/vsync pots on your monitor control board.

No problem plugging a Smash TV board into a mvs cab. As Reznor mentioned the monitor vert hold pot may require tweaking.
Also these Midway/Williams early 90s boardsets (NBA Jam, MK2, Smash TV) use -5 volts for the sound op-amps, dedicated mvs cabs do not use -5 volts so you may need to do a mod.
http://www.hardmvs.com/html/neg5volt.htm
Its a different story with encoders
"The only known problems are with later Midway games such as Smash TV, NBA JAM, Mortal Komat ( 1, 2 & 3 ) . These games use a vertical sync. frequency of around 56Hz ( the majority of games having a vertical sync of around 60Hz ). This vertical sync. frequency appears to be incompatible with some Sony TV sets, most notably the Sony WEGA series. These sets cannot sync to this frequency and the picture will roll vertically."
I use an Analog Devices AD724/725 encoders, MK2 colour is way out of phase using both pal and ntsc, I believe jrok users have the same problem. Its not just a vertical sync issue- for some reason the rgb signals do not convert correctly.

ttooddddyy said:

No problem plugging a Smash TV board into a mvs cab. As Reznor mentioned the monitor vert hold pot may require tweaking.
Also these Midway/Williams early 90s boardsets (NBA Jam, MK2, Smash TV) use -5 volts for the sound op-amps, dedicated mvs cabs do not use -5 volts so you may need to do a mod.
http://www.hardmvs.com/html/neg5volt.htm

Click to expand...

So it sounds like all I need to do is take a plastic screwdriver and turn the v pot under the monitor, correct? And I need to attach another wire to -5V on the power supply to the harness.

As for the JROK, it just depends on my TV. Hopefully it works with most so I can bring Smash TV to a friend's house.


Sounds easy. Thanks guys!

ttooddddyy said:

No problem plugging a Smash TV board into a mvs cab. As Reznor mentioned the monitor vert hold pot may require tweaking.
Also these Midway/Williams early 90s boardsets (NBA Jam, MK2, Smash TV) use -5 volts for the sound op-amps, dedicated mvs cabs do not use -5 volts so you may need to do a mod.
http://www.hardmvs.com/html/neg5volt.htm
Its a different story with encoders
"The only known problems are with later Midway games such as Smash TV, NBA JAM, Mortal Komat ( 1, 2 & 3 ) . These games use a vertical sync. frequency of around 56Hz ( the majority of games having a vertical sync of around 60Hz ). This vertical sync. frequency appears to be incompatible with some Sony TV sets, most notably the Sony WEGA series. These sets cannot sync to this frequency and the picture will roll vertically."
I use an Analog Devices AD724/725 encoders, MK2 colour is way out of phase using both pal and ntsc, I believe jrok users have the same problem. Its not just a vertical sync issue- for some reason the rgb signals do not convert correctly.

Click to expand...

No, the JROK works great with all of my Midway boards(MK1,2,3,KI2,NBA Hangtime, NFL Blitz). The color looks great, and my particular TV syncs up perfectly. The only problem is that the lower 1/8th or so of the image is a bit off the bottom of the screen.

EDIT-While testing some boards using my computers video input card I did notice the screwed up color. I was able to fix it by adjusting the macrovision timing in DScaler(video program I use). It seems that some boards that use different syncs seem to set off the macrovision protection in some products because the AGC signal isn't quite standard.

Reznor007 said:

No, the JROK works great with all of my Midway boards(MK1,2,3,KI2,NBA Hangtime, NFL Blitz). The color looks great, and my particular TV syncs up perfectly. The only problem is that the lower 1/8th or so of the image is a bit off the bottom of the screen.

EDIT-While testing some boards using my computers video input card I did notice the screwed up color. I was able to fix it by adjusting the macrovision timing in DScaler(video program I use). It seems that some boards that use different syncs seem to set off the macrovision protection in some products because the AGC signal isn't quite standard.

Click to expand...

Thats interesting, I reckon that with certain board sets the problem is more to do with the video/sync/encoded chroma burst waveforms than the actual frequencies. I would bet my left nut that the issue is to do with the colour burst being screwed up in the encoding process. It would be awesome to get to the bottom of this.

It looks like my -5V is wired up properly. I actually got the Candy that way. The sound from Smash TV is only the higher freq. sounds (no voices or explosions, just high pitched noise). Are there any recommendation on a fix or user error? I'm hoping its fixable so I don't have to buy a new sound board.

Also, I plugged both cables from the sound board into the main board. The power was obviously one direction only, but the other one (with the 20? pins) I may have had backwards, but I tried both ways and only one way I get sound, but its the high freqs only.

Thanks for all the help so far guys!

CarlDMC said:

Also, I plugged both cables from the sound board into the main board. The power was obviously one direction only, but the other one (with the 20? pins) I may have had backwards, but I tried both ways and only one way I get sound, but its the high freqs only.

Thanks for all the help so far guys!

Click to expand...

With the grey ribbon cable going between the boards, on the left or right edge it will be red instead of grey. That side of the cable must be plugged in so it's on the same side as pin 1 where you plug it into the main pcb and sound pcb. The spot on both the PCBs where the cable goes have two of the connecting pins labeled (i think pins 2 and 20). So, the part of the cable that has the red is plugged in so it's right next to the side near pins 1 and 2.

CarlDMC said:

It looks like my -5V is wired up properly. I actually got the Candy that way. The sound from Smash TV is only the higher freq. sounds (no voices or explosions, just high pitched noise). Are there any recommendation on a fix or user error? I'm hoping its fixable so I don't have to buy a new sound board.

Click to expand...

Did you wire a 5K pot to connector J2 on the sound board. These boards don't have a built-in volume knob, you have to add it yourself (unless it comes already wired from the previous owner).

The POT is already hooked up.
Also, I have that gray ribbon cable hooked up properly after it didn't have any sound when plugged in the other way.
Is it possible I damaged someting when the cable was switched?
I didn't smell anything cooking when I powered it on the first time.

CarlDMC said:

The POT is already hooked up.
Also, I have that gray ribbon cable hooked up properly after it didn't have any sound when plugged in the other way.
Is it possible I damaged someting when the cable was switched?
I didn't smell anything cooking when I powered it on the first time.

Click to expand...

Do you have that connector on J1 with a wire going from pin 1 to pin 4?

MKL said:

Do you have that connector on J1 with a wire going from pin 1 to pin 4?

Click to expand...

Yes, there is a wire on J1 connecting 1 to 4.

The pot seems to work, since the volume fades.
Also, all of the DIPs are at 0, does that matter?

Here's a thought....

Is Smash TV stereo? Because when I plug a 4-slot into my mono cab, similar sound problems occur.

Smash TV is not stereo. Have you checked to make sure that the positive and negative connections on the speaker are connected properly to the JAMMA speaker positve and negative connections?

The speakers are hooked up properly in mono. My one slot and other JAMMA boars play fine.

I'm guessing I have something faulty. I might have to drop test it.

You might check that the volume pot is connected correctly. You can find a Smash TV manual at www.crazykong.com

It has full schematics and wiring diagrams.

Wow, this is frustrating. Everything seems to be hooked up properly. I guess I should invest in a new sound board.