Inferno #2 - To Hell and Back

Looking at photos of the PCB:
W2 on the Video PCB connects to IC36 Pin 10. This signal is 5V connected to SR2 (Pull up)
W1 on the Video PCB connects to IC27 Pin 21. This signal is GND.
Their common point connects to IC27 Pin 36. This signal is RE (according to the turkey shoot schematics)

Looking at the 6802NS/6808 datasheet, I see:
* Pin 35 must be tied to 5V on the MC6802NS
** PIN 36 must be tied to ground for the MC6808.

My board has a 6802 installed, so I'm not sure what putting 5V on pin 36 would have done, other than enable the onboard RAM.

Edit:

I swapped for a 6808, leaving the jumper on W1. It did not make any difference. The crud is still present.
 
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Hey, glad to see it's looking a little bit better!

Unfortunately the scan of the Inferno schematics are pretty much illegible, and there is no scan of the Joust 2 schematics that I'm aware of, so the details of those jumpers may have to be traced out which I'm not super enthused about. But, progress I guess.

Maybe the Mystic Marathon drawing set can help? https://arcarc.xmission.com/PDF_Arc...hon_Drawing_Set_(16-3008-103)_May_15_1984.pdf

My board has a 6802 installed, so I'm not sure what putting 5V on pin 36 would have done, other than enable the onboard RAM.

Edit:

I swapped for a 6808, leaving the jumper on W1. It did not make any difference. The crud is still present.

The 6802/6808 is used for the sound, the 6809 CPU is the main logic.
 
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What parts did you use for the SRAM? There is a bunch of 6116 marked stuff from China that is either slow or glitchy. Have the original 4116 DRAM? (I've seen issues with some of the 4164 DRAM 'upgrades').

~Brad
 
What parts did you use for the SRAM? There is a bunch of 6116 marked stuff from China that is either slow or glitchy. Have the original 4116 DRAM? (I've seen issues with some of the 4164 DRAM 'upgrades').

~Brad
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I used these 6116 equivalents I bought from TwistyWrist Arcade. The Datasheet for these puts the access time at 120ns (max). It could be it's too slow... I've ordered some faster CY6116A-55PC from APAR, with max access times of 55ns... We will see if that makes anything better.

In the meantime, I fixed the dead amplifier, and now we have sound... Although I have no controls. Lol.


Harnessing is nearly done. I just realized that I didn't have three colors of wire.... So I've put an express order in to Wirebot to get that resolved.

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Not in public as I know, but many in collectors hands :cool:
No joke, I thought about pinging some Austrian collectors to see if I could say hello :)
 
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Coin Doors have received an enamel coating and have been reinstalled and wired up. I realize I need to get some locks for them though. D'oh! At least the test/advance switches are working as intended. It's funny, none of my other Williams cabs aside Sinistar actually had the coin vault advance switch installed, as they were total deconversions, so I was at first unsure of what that switch was, or how to wire it up, but I figured it out, lol. Very cool feature from Williams, that.

At the moment: Here are the remaining todos and blockers:

Cabinet
  • Install Marquee Light Fixture (Waiting on a new Ballast to Arrive)
  • Install Marquee (Need to get it)
  • Need to buy some coin door tubes. Both are missing. Are these just standard pipe available at Home Depot or something?
  • Finish Wiring Harness (As per usual, waiting on good ole USPS)
  • Install Cabinet Locking Feature for upper coin door.
Control Panel
  • Final Assembly of plate/CPO/Wooden panel is pending another USPS package (for foam). Sensing a theme here?
  • For the moment, I will just use 4x Wicos to run the game, until I am able to secure Blaster style optical sticks.
  • I need to get a couple more of the countersunk screws that secure the plate to the panel. I was missing a few. I assume I can just take some of the existing ones to TrueValue and find new ones... Hopefully.
PCB

Even before the game is finished, I'm still fighting demons here (ha). I suspect that the problem causing the noise is on the video board somewhere, rather than the CPU board, as if I touch the three graphics ROMs, it actually seems to affect the noise in noticeable ways. This is really weird.


Ordinarily, I would suspect
  • Bad Roms - But these were NOS Roms and fresh burned, and I cleaned them for good measure.
  • Bad Voltage - But the board is doing the same thing when on my switcher-powered bench setup
  • Bad GND - I have tested continuity from the PCB to the wall ok.
  • Cold Solder - But I reflowed the solder and it's still doing the same thing.
  • Bad Sockets - I have some new sockets on order... (USPS Please) but I am not 100% this is the issue either because...
As a test, I did try removing the ROMs entirely, hoping I would get a black background, or vertical lines, but I still got some noise (though the center noise I was experiencing was gone) so I'm really not sure what to think here. I do think that whatever this is, is confined on the video board. At least I'm hoping...

I reinserted the ROMs one at a time, and the nicest it ever looked was when I had put IC41 back in only. There was no noise in the center of the screen, and it looked very close to what I had in mame when I left IC41 in and replaced IC57 and 58 with empty files.


Here's what it looked like in mame:

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Noticeably, while there wasn't any fuckery in the center of the map... On either side of the Grand Lizard's visible stripes, there was still noise/garbage. So I'm really not 100% sure.
 
Good News, Bad News, and So-So News.

The Good News:

Cabinet Harnessing is complete!

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So that means too that the coin door lights are working, and everything looks very pretty! Unfortunately, I don't have the Inferno marquee (yet) so I used the only spare Williams marquee I have to diffuse the light - Joust 2. Lol.

The only exception to this completeness is I ran out of pins for the 24 pin connector used on the control panel, so I have to order a couple more.

The Bad News:

Unfortunately the CPO I got from Galloping Ghost had some incorrect dimensions, so I have to delay putting the control panel together until I can get the refinements done. I don't blame them for this one at all... I figured it might take an iteration or two. The CPO I received was very high quality, even if the dimensions were off.

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The So-So News:
The garbage on the screen is still present. Unfortunately, it's not a RAM issue either. As it turns out, Inferno can't even handle faster 6116 RAM (55ns access from APAR (CY6116A-55PC) - it starts freaking out and resetting after some hilarious visual glitches. So I'm back to standard 120ns access 6116 RAM. This is what Inferno shipped with originally. My money is now squarely on bad video ROM sockets. hopefully I'll find out tomorrow.

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As an added bonus, I received an upper door lock kit from braedel, so I was able to test the machine with the doors closed. The harness seems to fit, and everything looks okay.

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Well, this took me all damn day, but I Inferno'd the Joust II PCB. One step closer to having this cabinet back again!

Also went ahead and cadded up the Inferno plate. Hopefully it's accurate.

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So how hard was it to convert? I was told swapping joust 2 to inferno isn't very easy. I'd like to build an inferno to go with my Williams harder to find games line up. And what's the width of the cabinet, is it joust width? I'm thinking if it is I can go off a joust cabinet and make the angle changes for the tube.
 
So how hard was it to convert? I was told swapping joust 2 to inferno isn't very easy.
It's not that hard to do. It's roughly $100 in parts (just in the amount of ROMs needed), but not difficult. Just swap a few jumpers around.
Mikes Arcade has a guide on how to do this. I was thinking about making an illustrated guide as well, because I did mess up following these instructions.

I'd like to build an inferno to go with my Williams harder to find games line up. And what's the width of the cabinet, is it joust width? I'm thinking if it is I can go off a joust cabinet and make the angle changes for the tube.
Inferno *is* the same width as Joust, but the cabinet profile is subtly different, and the control panel is very different. An Inferno control panel would not fit into a Joust cabinet as it rises too much as it extends back, and if you tilted the monitor back in a Joust cab, you may run into control panel issues.
 
It's not that hard to do. It's roughly $100 in parts (just in the amount of ROMs needed), but not difficult. Just swap a few jumpers around.
Mikes Arcade has a guide on how to do this. I was thinking about making an illustrated guide as well, because I did mess up following these instructions.


Inferno *is* the same width as Joust, but the cabinet profile is subtly different, and the control panel is very different. An Inferno control panel would not fit into a Joust cabinet as it rises too much as it extends back, and if you tilted the monitor back in a Joust cab, you may run into control panel issues.
Oh sweet! Well if you do i definitely would love to get another rare game together although some people will hate on it i doubt id find an original cabinet so id build a new cabinet for sure. I hope to get my blaster joystick back soon and get it 3D scanned to make some new handles and possibly make 2 more joysticks if I can get someone to machine the metal parts.
 
Okidoke!

The garbage on the screen is GONE! This PCB set is now 100%! Woohoo! I don't think there is anything really left to do in the back of the machine now.

The problem turned out to be BOTH bad sockets and bad ROMs on the video board. IC57 and IC58 specifically.


Also - @braedel is awesome and sent me some proper labels I could use instead of my label-maker labels, so it definitely looks a little more authentic.
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Oh sweet! Well if you do i definitely would love to get another rare game together although some people will hate on it i doubt id find an original cabinet so id build a new cabinet for sure. I hope to get my blaster joystick back soon and get it 3D scanned to make some new handles and possibly make 2 more joysticks if I can get someone to machine the metal parts.

See attached.
 

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Okidoke!

The garbage on the screen is GONE! This PCB set is now 100%! Woohoo! I don't think there is anything really left to do in the back of the machine now.

The problem turned out to be BOTH bad sockets and bad ROMs on the video board. IC57 and IC58 specifically.


Also - @braedel is awesome and sent me some proper labels I could use instead of my label-maker labels, so it definitely looks a little more authentic.
View attachment 793188




See attached.
Awesome I appreciate posting the conversion. I can possibly get my hands on a mystic board set so maybe I could trade the rom board if the main board is the same. Also for wiring did you make all new or utilized joust 2 wiring? I'm also excited to see how yours will looked when you're finished. Awesome work!
 
Awesome I appreciate posting the conversion. I can possibly get my hands on a mystic board set so maybe I could trade the rom board if the main board is the same.
At a glance, Mystic Marathon is not convertible to Inferno - either board.


The video board is laid out differently than Inferno/Joust 2 and is missing the ROM setting jumpers.


The CPU board doesn't have enough inputs for Inferno either.
Also for wiring did you make all new or utilized joust 2 wiring? I'm also excited to see how yours will looked when you're finished.
I did the entire LC harness from scratch. The AC Harness is original to my machine.
 
Annnnd we're at playability!!

Today I recapped the monitor and put together a rough version of the control panel, just to make it playable.



The control panel harness was a major pain in the ass and took HOURS to build, but it's done. (Mostly. Still waiting on extra molex pins, hence the alligator clip)

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I used some random joysticks I had laying around, but they seem to do the trick. It's very playable. My wife and I did a two player game earlier - it's very fun.

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Remaining to-dos:
  • Pick up Marquee
  • Get new CPO revision done
  • Install coin tubes
  • New Joysticks (eventually)
Pretty much everything now can be done from the front of the game, so soon it will move into the arcade proper.
 
At a glance, Mystic Marathon is not convertible to Inferno - either board.


The video board is laid out differently than Inferno/Joust 2 and is missing the ROM setting jumpers.


The CPU board doesn't have enough inputs for Inferno either.

I did the entire LC harness from scratch. The AC Harness is original to my machine.

At a glance, Mystic Marathon is not convertible to Inferno - either board.


The video board is laid out differently than Inferno/Joust 2 and is missing the ROM setting jumpers.


The CPU board doesn't have enough inputs for Inferno either.

I did the entire LC harness from scratch. The AC Harness is original to my machine.
Ahh dang that sucks, well good to know before I pulled the trigger on the mystic i guess I'll be on the look for a joust 2 board set then. Did you just go off of the schematics and was it somewhat easy to read? I sometimes have issues reading them 😂. I also Just bought an cpo, bezel, annd side anrt I probably won't be using on my game from a buddy for a great price and when I get to build mine I'm making a stencil. I've made out several different looks and so far I like the cyclops one best.
 

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Another actual original inferno part arrived today.

20250119_144045.jpg

I am very lucky to have such good friends. I am very thankful to the friend who has this in his stock and is letting me use it for my machine. Very, very, grateful. You know who you are!

It had some goop on it from stickers on the past:
20250119_111842.jpg

Two hours of isopropyl alcohol, warm water, dish soap, and gentle scrubbing got rid of the problem though! I wanted to take it nice and slow because I would be beside myself if I damaged this thing.

It looks absolutely INCREDIBLE installed on the cabinet. The big problem I have with the repro Marquees is that the light shines through the black, bleeding it out and making it look grey. Not so with this one! Just glorious.

To my generous friend: Thank you again 🙏

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Nice progress!!

Stumbled onto Scott's new listing and adding here in case a back up PCB is needed.


^^^ Private Demonic FB group. Can't see 5h!t. :rolleyes:
 
Another actual original inferno part arrived today.

View attachment 794278

I am very lucky to have such good friends. I am very thankful to the friend who has this in his stock and is letting me use it for my machine. Very, very, grateful. You know who you are!

It had some goop on it from stickers on the past:
View attachment 794280

Two hours of isopropyl alcohol, warm water, dish soap, and gentle scrubbing got rid of the problem though! I wanted to take it nice and slow because I would be beside myself if I damaged this thing.

It looks absolutely INCREDIBLE installed on the cabinet. The big problem I have with the repro Marquees is that the light shines through the black, bleeding it out and making it look grey. Not so with this one! Just glorious.

To my generous friend: Thank you again 🙏

View attachment 794281
Wow
 
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