Arcade Machine Hardware Discussion

We started talking a lot about this in the SNES sound hardware discussion, so I thought hell, why not. I was talking about how I thought the Neo Geo's sound hardware was bad, but holly hell, this has got to be the worst sounding arcade board in existence: https://www.youtube.com/watch?v=Iuhx1PyLppQ http://system16.com/hardware.php?id=952 Having sound solely comprised of two OKI6295s is a bad idea. That arcade board is really an anomaly over all; it's from 1994, You'd dismiss this for being a low-budget POS, but it has a 28MHz ARM processor.

Edit: Video hardware information was false, so I removed it.

At first I thought this was just a bad programming job, theb I found documentation for the chips, and they have a sampling rate of either 8khz or 6.5khz, no other pitches are available. Then there's a lowpass filter, but 8khz sounds bad with or without a lowpass filter anyway.

Probably it was designed by deaf engineers thinking "Who cares about sound anyway ?".

That and in a noisy arcade, crystal clear audio might not necessarily be heard over the two adjacent games also in use. When your game's cabinet is as physically imposing as a Dance Dance Revolution or other 2-player Bemani game, sparing no expense for audio is justified. But not all games are that big.

Who knows what Mitchell were thinking?

Considering that it has limited sample streaming, it sounds pretty good. It could have been much worse in the wrong hands: https://www.youtube.com/watch?v=vZ_Qas_Yl8E

Is this for real?


Same here; it sounds too bad to be in hardware. It actually reminds me a lot of a lower quality GBA game. I've know of several arcade machines with the OKI6295, but none of them rely on it solely, usually pairing it with the YM2151 (CPS1). I can't believe how long it lasted though considering how low spec it is (look at the dates of some of these games): http://vgmrips.net/packs/chip/okim6295?

I actually downloaded the rom for the game and looked at it in MAME, and it turns out that this doesn't actually have 3BG layers; it only has two. One of the layers appears to use 8x8 tiles, while the other appears to use 16x16. The status bar is actually just sprites; 8x8 numbers used to represent the score are actually 16x16 sprites, which seems like a huge waste of bandwidth. The game didn't ever actually have sprite dropout of any kind, despite how heavily it relies on sprites. (Several large background elements in the game are even made of sprites) You know Sega would have relegated this hardware to puzzle games only.


It appears to be Data East's arcade machine that Mitchell just used. I'd ask what Data East was doing first. It actually appears they had an otherwise identical arcade machine aside from the sound hardware that was released earlier: http://system16.com/hardware.php?id=954 It's still 8 channels, but it sounds clearly better: https://www.youtube.com/watch?v=2QCD8u-3YTw Of course, both companies weren't exactly rich, so they had to work with "substandard" hardware.

I bet licensing Yamaha sound chips wasn't free either.

I'm afraid it is. Here's my write-up: http://www.chrismcovell.com/gbbooster.html

"Well, I plugged the GB Hunter in... the GB hunter logo scaled onto the screen, and (with a GB cartridge properly inserted), the 'Loading...' screen came on for a second. Then, the horror began.

The GB game started running, of course, but what came out of my TV's speakers was not GameBoy sound, but a horrible screechy 'song' played as a looped sample at about 4khz... So, the reports were true; this thing didn't emulate the GB sound at all. In fact, total silence is preferrable to this song... What were they thinking???"

Trivia time: the horrible sound from the GB Hunter seems to be a rendition of "That's the Way It Is", a C-64 tune. It's just a bit hard to recognize.

Well, this is relevant to arcade machine hardware, although not the discussion of that Data East arcade machine: Do most of the arcade game boards from the late 80's and early 90's generally use some sort of (physically) standard sized rom chips? (Seems like piracy would be really easy though if this is the case, so probably not.) I've always wanted to own an arcade board, but while I regularly see deals for system boards with shitty games for less than $250, the games you'd actually want to buy the system for go for well over $500, with few exceptions. In addition, it's almost impossible to get game boards by themselves for some reason, unless the ratio of system pcbs to game pcbs is roughly 1:1. I'm hoping I can get a $50 eeprom programmer and a bunch of eeprom chips and make a few games; I don't know if I'm being delusional about this, because I've never had any experience with this exact sort of thing.

What would be really neat is a device that uses a USB port (or several) that splits the signal to be massively parallel to where you could put a wire in every slot for every rom chip on the game board. You could then hook it up to a Raspberry Pi and make a "SD to CPS1" or something like that. Probably wouldn't work for about 1000 different reasons though.

...Old systems with palette rom, I imagine, would actually be able to play 60fps, full color FMV then...

Yup, it was a problem. Hence why so many later arcade boards have "unclonable" and/or "suiciding" parts.

I don't think the CPS1 (which is mainly why the CPS2 exists) or Irem M72 and M92 do, or at least I really hope not, as these are the only boards I really have a strong interest in. R-Type and R-Type II (if you can even find it) are as expensive as hell, but I found a deal for "Pound for Pound" that uses the same board for only $100 (with free shipping ): https://www.ebay.com/itm/POUND-FOR-POUN ... 0005.m1851

I found that common 27C020 AMD eprom chips work with M92 game boards: http://www.jammarcade.net/irem-m92-double-repair-log-1/

According to this (http://arcadehacker.blogspot.com/2015/0 ... art-1.html) The video processor for each CPS1 game is on the game board itself? This (http://www.jammarcade.net/strider-conversion/) seems to cement that by saying:


It's not impossible to make it work, like how this person is going through the rom and manually changing the pointers, but it's still more work than I would have hoped.

I haven't found anything about the M72, but I'm not getting all of these at once anyway.

Triple post! Because I'm not about to buy a $200 supergun, it occurs to me that the Jamma standard has a pins for three buttons, along with a start button. Luckily, so does this:



Because the controller port is identical to a serial port (?) you could just get a male to female serial port cable and stick the wires from the Jamma harness accordingly. (I have no idea how the six button controller works)



Your power supply is going to have to supply 5V anyway, so that's fine. The real problem seems to be a video converter; I'd have thought it'd be all be analog, but all the devices I've seen appear digital, which more than likely means there's going to be lag. Does anyone have any suggestions?

Edit: Wait, I'm an idiot, looking at the schematic, even with the standard controller, some buttons share the same pins somehow. Darn.

Edit 2: Actually, I'm not sure... I've found some stuff that seems to imply each button has one pin assigned to it, and I have no idea what "select" means on the above picture.

On the 3-button controller, "Select" is an output from the console, roughly analogous to $4016 D0 out on an NES or Super NES. It switches the A, B, C, and Start lines between two of the pairs of buttons. On the 6-button controller, it switches more lines if toggled multiple times within a millisecond. (Source)

Your JAMMA harness will need a circuit that toggles Select, latches the output in both states, and relays it to the system board.

...In other words, I need to find another solution for a controller. I could make a somewhat-ghetto arcade controller out of wood and screws from Lowes and it would be largely cheaper than any one I could buy, but I kind of want an actual handheld controller with a d-pad. An arcade joystick without a cabinet just feels off to me.

I can't believe how expensive some of this stuff is for people who don't know what they're doing. Individual parts, like a power supply or signal converter, are pretty cheap, but once you throw them altogether in a box, it eclipses the cost of the actual arcade pcb. Also, what's the fun in that?

If you're really looking for a cheap option, sacrifice one Genesis controller by removing the IC and wiring the eight outputs directly. It won't be a compatible pinout with the existing DE9-joystick game consoles (none support 8 digital outputs).

The Neo Geo DA15 port could be worth mimicking instead.

It appears I found a solution:





So I don't have to mess up the port on the controller itself, (soldering, unless the wires will actually stay in the sockets) I've found some extension cords for the Neo Geo on ebay. (Apparently, it's just a standard computer cable like the Genesis.) All of this put together is pretty expensive, but it's still cheaper than a Jamma control stick and probably more comfortable. Plus, if I do want to switch to a control stick, there is also the one available for the Neo Geo, although it's more expensive than the already expensive gamepad.

Edit: A new post was made while I was writing this:


It appears I wasn't quite as clever as I thought.

Yeah, I'm going to go with a Neo Geo controller. Even if it's more expensive, I don't really feel like destroying a Genesis controller.

Well, I actually did find a reasonably priced supergun, and with Neo Geo controller ports: https://www.ebay.com/itm/Supergun-ProGa ... SwOyJX6pvu The only thing that sucks is the lack of component or even composite output. However, I know of a couple VGA to composite (not component, sadly) adapters, but they all have a 5V DC plug. The supergun wants an ATX power supply though, so it's not like an arcade power supply to where I could just screw this onto the front of it along with the Jamma wiring harness, so I have no idea how I'm going to power it. I could use the included 5V DC to USB and a USB wall adapter, but then my arcade machine setup would be taking up two wall outlets and just look even more ghetto.

There's actually a 3/6 button Sega Genesis to Neo Geo controller port by the same seller (I presume it uses the unused pins for extra buttons), so I don't have to spend $100 on two Neo Geo CD controllers, thank God. There's even one for the SNES and the PS1/PS2, but I don't like how they mapped the buttons (luckily they show you how it's mapped in a picture).

http://www.neogaf.com/forum/showthread.php?p=246043508
https://en.wikipedia.org/wiki/Talk:CP_System_II

Wow, what a load of incorrect information! Since when did CPS2 games have 24-bit RGB and 8-bit transparency?

The CPS2 does have 24bit RGB though. A bit (or rather, byte ) overkill, but since the CPS1 had 12bit RGB, it was probably easiest to just double it. (Definately the biggest improvement; I much prefer the sound of CPS1 games, those without added Q sound of course.) 8bit alpha transparency is a load of BS though; it's pretty clear that person has no clue what they're talking about. I don't know why people keep bringing up the Neo Geo's increased memory range for graphics when even it used bank switching by the end of its life. The biggest sin of all from that thread though, is the guy calling the SNES SFA2 port impressive for the hardware.

All the CPS2 games I've seen only use 12 bit color.

From what I've been reading now, I think we're both wrong. A good number of sources seem to claim that it uses 12bit RGB, but with 4 bits of luminescence, which seems pretty odd, but you've got to figure that it probably would have been more work to get 15bit RGB and 1 bit of luminescence like the Neo Geo. This lines up from what I've seen; things like the background of Ryu's stage in Street Fighter Alpha 2 would show more obvious banding if it were 12 bit color, and taking a screenshot and analysing the color values, they don't match 15bit RGB being rounded to 24bit RGB for the display, like the M92 or other arcade machines I know that use 15bit RGB.

A Neo Geo controller connector is definitely the standard for a supergun, and all the ones I own have them. If you're gonna build your own you might as well go with that. It's a very easy plug to get ahold of, it's able to map more buttons than the MegaDrive one, and also uses direct switches with no signal modulation.

Don't convert arcade video signal to composite. If you want to use it on a standard American TV, get a component encoder (I got one for around $50), and don't build it into your supergun. Just hook it up externally, so you can get decent video quality from all your other consoles, too.
The base supergun (a power supply + wiring from a JAMMA connector to the PSU and plugs for controls and a SCART video output) is actually really cheap, but it takes some work to make them. You probably want adjustable resistors (potmeters) on both the Red, Green, and Blue video signals, since these can easily vary between games.

As for the chips, most arcade games will have some special chips that makes the games difficulty to bootleg (and often you'd even see them scratching out the manufacturer and model logos), but in all of the 60-70 arcade PCBs that I own, I have NEVER seen one that doesn't use standard sizes ROM chips, making them very easy to replace.
Typically program ROMs are even socketed EPROMs, making them very homebrew/hack friendly, since the developers would usually need to make changes close to release, or even afterwards if exploits were found in the arcades. Sound and graphics data tend to be mask ROMs, but it really depends on the game. I even got my EspGaluda with an extra hacked rom that allows saving the high score data.

The $500 price point and above is usually reserved for rare'ish shooters, most arcade games shouldn't set you back that much. What games are you looking for in particular? Personally I found most of my games for less than $100, or even $50, but the prices in general have gone up a bit the last few years. Some of my games cost a fortune, but those are specifically selected titles that I cherish more than any other games I own.

Regarding the system pcb to game pcb ratio:
The only arcade system that was ever really succesful with separately sold catridges was the Neo Geo. To a smaller extend ST-V and PlayChoice (both based on console hardware) and the PGM (a Neo Geo clone). Even the CPS2 and the Taito F3 system, which are the only other "major" cartridge based arcade systems I can think of, are usually sold along with the motherboard, since that's how they were distributed to arcades, to be plugged into generic JAMMA cabinets. SNK were the only ones who really got away with expecting arcades to have (one or more) existing Neo Geo cabinets they could just plug loose carts into.

Other systems which have both motherboards and daughter (game) boards don't work well with switching out games. Examples are the Konami GX variants and CPS1. Even separating the games from their motherboards can be difficult (compared to cartridges), and only certain motherboards will work with certain games. I've never seen anyone switching out these games, and I wouldn't recommend trying it. If you're looking for CPS1 games, don't buy loose daughter- or motherboards.

Furthermore, some CPS1 games did indeed have the suicide thing. It's easier to hack/fix than CPS2, but most likely you'd end up with one that needs fresh batteries, and won't work if you start switching out the ROMs. The ones that have it are usually the later ones, like Three Wonders, Cadillacs and Dinosaurs and King of Dragons. Fortunately the CPS1 games that I own (Varth, Pang 3, and Ghouls n Ghosts/Daimakaimura), don't have it.

When I was a regular on TetrisConcept.net, the second and third Tetris the Grand Master games were fairly expensive, such as roughly $1,600 for the TGM3 PCB. Or have they come down since then?

TGM3 is a strange one, since it relies on Type X hardware, similarly to most other newer arcade games, such as Street Fighter IV.
The game itself is not a PCB, it's just a hard drive and a USB dongle or something like that. I never really got into the Type X series of "arcade hardware", since it is literally just a Windows PC with a specific hardware configuration. I'm not really interested in that stuff.

I don't know when you were on TC, but I bought my TGM2 PCB around three years ago (just before the game attracted new attention via AGDQ), and the price point has grown to nearly three times what I paid since then (and I paid a lot, too). It's definitely one of the most expensive bare arcade PCBs out there.

That one supergun I found was $80 including shipping. It's pretty pricey, but if I were to make my own, I'd have to buy a soldering kit, (I've used one a dozen times at school and my grandfather's shop, but I don't own one) which would cost about $30, then the JAMMA harness, video converter, and Neo Geo plug ends and whatnot, which at that point, I probably wouldn't be saving more than $20. I still need to get a power supply, but while the ones with -5V are slightly more expensive, they still aren't ever over $30 if even that.


Most American CRTs don't have component cables. Thank God mine does though. (I don't mean to brag, but it's also a 27" flatscreen CRT. ) I'd prefer to get a VGA to component encoder so I don't need another cable (and I can use my CRT for my computer if I want to), but I haven't been able to find one, only SCART to component converters.


I don't own any consoles with a SCART connector, and I'm not even sure one with a VGA connector exists. Not really related, but it pisses me off how expensive GameCube component cables are. Wii component cables are much, much cheaper, but I prefer to use my GameCube for GameCube games so I don't have to deal with the menu.


Plan on opening an arcade?


The games I have any interest in owning are any of the original three Street Fighter IIs, Strider, Ghouls and Ghosts, Final Fight, R-Type, R-Type II, R-Type Leo, Ninja Baseball Batman, Undercover Cops (Alpha Renewal or Japanese), In the Hunt, or Gunforce II. I'm not aware of any of the CPS1 games I would want being rare, or the original R-Type, but aside for Street Fighter II, they all go for an arm and a leg. The ones I didn't mention are actually pretty rare and go for even more; in retrospect, Gunforce II going for $300 on the one eBay auction I bided on probably wasn't that bad of a deal.

I know all M92 games will work on the same game board if you just switch the ROM chips; the sound is supposed to be encrypted for each board or something, but I know that it's been cracked. However, because people know this, that means that even shit like the original Gunforce goes for $200. Not many games use the M72, but they all use boards that System16 calls "similar base hardware to M72, but all with slight differences", whatever that means; it's the exact same V30, Z80, and YM2151, all at the same clockspeed. The video hardware looks the same, with all the games I've inspected having the same 384x256 resolution, 15bit color, and 512 total onscreen colors. I presume the only difference between them is that the video hardware registers changed places or something to prevent piracy.


Only the later ones; all the ones I want don't, luckily.

For 240p/480i that you'll be getting out of any JAMMA board, properly encoded S-Video will look as good as component. Plenty of (later) CRT TVs in non-SCART regions have S-Video in.

$80 is a fairly good price for a supergun I think. I'd just go for that. I recommend investing in a soldering kit anyway though, it's a great thing to have when you're getting into this stuff.


I'm not an expert on this, but that is probably because with RGB SCART you are expecting a 15khz signal (240p), while VGA supports all sorts of resolutions that would make converting to component a lot more complex (or maybe not, I'm not actually sure how component works).
Either way, when dealing with most arcade hardware (up until around Naomi and Atomiswave), 15khz video is all you need to think about, so there's no advantage in the VGA standard aside from the more practical plug.


I just like video games


Yeah... Those are all pretty expensive games Not sure if any are in the $500 area aside from GnG (at least that's what I paid), but the R-Types could definitely push it.


I had no idea it was easy to convert the original Gunforce. Might try to look into that, though I'm not a fan of conversions... In my mindset, if you aren't playing the original game, it might as well be mame.
I paid around $30 for Gunforce

It's not really easy to convert Gunforce to Gunforce 2 or other M92 titles, if only because the way the program ROM is mapped prohibits a straight ROM swap. You have to pull an extra address line and re-do the /OE decoding in order to map H1/L1 at 0x80000 instead of 0x40000, which is the max a stock GF1 board will do. Your other obstacle is the encrypted sound CPU, which applies a decryption table to the fetched opcodes, but not data.

I made a program to decrypt M92 sound programs, where it must be fed a trace log from the sound CPU from MAME, and uses that to build a map of known program counter locations. This mostly works, though corner-case code is not hit if it didn't get executed during logging.

Take a look at eBay.


When was this? It's hard enough to find it for less than $200 now.


pull?


/OE?


H1/L1?

Is the problem that the Gunforce 1 board doesn't address as much graphics data, or what?


I knew this, but I also know that a program had been made to decrypt them and re encrypt them for different games. I never knew you made it though. Gunforce 1, along with Major Title 2, are the most common M92 boards, so I imagined people have made re-encrypted sound program roms for these.

The problem is that Gunforce 1's bottom board doesn't address as much program ROM, like I wrote in my post. You can use your favorite search engine to look up other terms adorned with question marks.



Re-encrypting sound ROMs is not a great solution, because then you have made it work on only one board. These days the solution is to disable encryption on the CPU and run decrypted ROMs.

Not in a way I didn't understand.


I did before asking you, it's that nothing good showed up. Any variation of "pulling address lines" gives results for case specific definitions. I'm not intentionally trying to bother you.


Gunforce 1 and Major Title 2 are probobly the only boards people will bother with conversions for though. How would you go about disabling sound encryption? Trust me, I looked it up before asking you.

Edit: It appears Major Title 2 doesn't share Gunforce's problem of not being able to address enough program data. At least, I've seen YouTube videos of both R-Type Leo and Geo Storm using the Major Title 2 board, and it doesn't appear to be tinkered.

Four to five years ago. Was looking for GF2, but couldn't find it at a decent price. Was pretty let down by how much worse the first game is.

It probably doesn't share any of the same development team. Of course, there's no way of knowing because Gunforce II doesn't have any credits. Text for it might exist in the program rom though.

I think it's pretty obvious who made GunForce 2 though

Oh yeah. I forgot about how that vastly-inferior spiritual successor they made has credits.

Come on now! I know you don't mean that.

Yeah, I was joking. However, while I like Metal Slug (mainly the first game. To me, 1>2(overclocked)>X>3. Haven't played any after this and don't care to.) I enjoy playing Gunforce II much more. The one thing I can appreciate more about Metal Slug though is the difficulty; Gunforce II has to be the easiest arcade game around. I would have loved to see a true sequel to Gunforce II, but never mind the real business reasons we never got it and got Metal Slug instead, your characters presumably die at the end of the game anyway.

I'm pretty sure if we got an actual GunForce 3 it would have been pretty much identical to Metal Slug. They even reused the scream sounds (from the first game, too)