JAMMA Video Standard | Hacker News Reader

JAMMA Video Standard

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130 pointsingve23 comments

Some of the terminology used in the arcade world is a bit confusing, so just to clarify:

'JAMMA' is the original arcade standard developed in the 1980s. It specified a standardized edge connector pinout to interface an arcade PCB with the rest of the arcade cabinet (i.e the power, video, sound, and controls).

'JAMMA 2' aka 'JAMMA Video Standard' aka 'JVS' was/is a successor standard that made things a bit easier by using separate connectors for video, I/O, etc. instead of putting everything on one giant edge connector. That standard is what this article is about.

https://en.wikipedia.org/wiki/Japan_Amusement_Machine_and_Ma...

Noooo HN, don't get me started again : )

I've got a vintage arcade cab at home, with its old CRT, since a few years now: originally it wasn't a JAMMA cab then someone modified it to be JAMMA because at some point JAMMA "won" in the arcade world. Everything is still working, including the money slots (they're still using old 20 "Francs", belgian coins that is and I still have 4 of these coins). But I wired a button to the pin that adds money: easier/faster. I put one my PCB in "free play" mode too (using dip switches on the PCB itself).

I've got a few original PCBs and some bootlegs, all vintage.

But mostly I'm hooking a Raspberry with a Pi2JAMMA adapter and then I've got thousands of games working (most are crap, some are little gems).

When it's all JAMMA it's convenient: I can just swap PCBs or the Raspberry Pi and turn the machine on and everything just works.

On a semi-related sidenote many criticize old arcade game saying they were "exploitative because you had to put coins" but, honestly, I find that complete bullshit. If you played these games a bit, you could get good at it and finish the game on one credit, playing for 30 minutes or even 45 minutes on one coin.

I can guarantee you: many modern games are much exploitative than these old arcade games. Be it in-game ads or in-game buying or all the A/B testing to make sure its addictive etc.

Another benefit of these old arcade games: they're simpler, which kids do love. My six years old daughter loves our arcade machine and often asks me: "Dad please, can we turn the arcade on?". I don't have to worry about her getting ads or disturbing videos or being spied upon.

Then of course playing Robotron 2084 with two joysticks, as it is meant to be played (no buttons used in that game) is great. The fast-paced action, incredible responsiveness and original controls (one joystick to move in eight directions, the other joystick to fire in eight directions) makes for timeless fun.

I don't play games on PCs / console since a very long time. But once in a while I turn on the good old arcade and play a bit...

It's a great thing to have at home.

Wife loves it: it's in the living room. It has presence too. Visitors typically loves it, even if they're not into videogames at all.

It also doubles as a very convenient laptop stand!

Are you running the latest version of mame on your pi? I’ve always used amd64 on my arcade cab so I can not run 20 year old mame builds.

I should know better (I've got lots of RPis I installed myself) but in this case I really don't know: a friend of mine just dd'ed his working setup on to a memory card.

> If you played these games a bit, you could get good at it and finish the game on one credit, playing for 30 minutes or even 45 minutes on one coin.

This varies a bit depending on the game, but it’s safe to say that the average play on an average arcade game is much less than 30 minutes per credit. For example, one game of Dance Dance Revolution typically consists of three 90 second songs with the option of earning a fourth bonus song as a reward for skill. Factoring in sixty seconds for menus between songs a player will play between 7-10 minutes a credit. This number is much closer to what the average game targets. You’ll see similar numbers in pinball and racing games.

For the aforementioned robotron and games of that era, you're mostly limited by your skill. You won't get a game over until you die. Look up a record breaking score run. It'll last hours. Of course, you can't get that good until you sink a ton of credits into the game...

It was mostly in the 90s when they figured out they should probably limit game length per credit, like a restaurant trying to turn over a table as many times as possible. Stuff like NBA Jam and Street Fighter II set the stage for that even before DDR.

RS-485 over USB connectors... AAAAHHHH! (Presumably to reuse common connectors and cheaply available cables over more custom things, but still a bit surprising for something as simple as RS-485 - seeing this more nowadays with devices using HDMI and USB3 cables, because they are cheaply available cables with somewhat defined performance for highspeed signals)

Nowadays it's very common to run RS-232 over RJ-45 connectors. The weirdest I have seen was one cheap NAS that ran the SATA data and power cables over a PCIe connector.

> If I can’t go to the arcade, at least I can bring a favourite game home, right?

Wait, you guys have arcades where you live?? There used to be a proper arcade in my city years ago but it shut down.

These days the closest we get are a couple of bars that have lots of arcade games. But it’s not the same. Because it feels like a bar, not an arcade, even though arcade machines are there.

Where can I move to that there are real arcades?

Can you describe what a "real" or "proper" arcade does feel like, if not a place with lots of arcade games?

Maybe one of these would fit your description: galloping ghost in IL, Asheville pinball museum in NC, Game Galaxy in TN.

A chain option I assume you can find lots of places depending on whether OP considers it a real arcade or a bar: Dave & Buster's

Denver: https://the1uparcadebar.com This place is awesome, beers, games, bar food.

Asking the question that the title (incorrectly) implies: were there standard formats or codecs in which arcade games encoded their promotional intro videos that would loop to bring in new players? Or was this more or less at the manufacturer's discretion? As one of the most storage-hungry assets compared to game logic, textures, and audio, there must have been tremendous attention placed towards reducing the size of those videos.

I think a lot of demos wouldn't be videos, instead it actually plays the game for real by feeding it a set of pre-recorded inputs.

It's generally called 'Attract mode', and at least from what I recall from the golden era arcade games (from the mid '80s up until the mid '90s) it's never an intro video, rather something done completely in-engine. Unless you're thinking lasergames, but that's ... all video.

You must mean https://en.wikipedia.org/wiki/American_Laser_Games , which uses the random-access capabilities of a laserdisc player.

I believe its the general term for games which were pre rendered/animated as opposed to being sprite based or rendered during game play. The most common wxample I recall is probably https://en.m.wikipedia.org/wiki/Dragon%27s_Lair_(1983_video_...

Thanks. I should have linked to https://en.wikipedia.org/wiki/Interactive_film#Laserdisc_gam...

Very interesting article, but title isn't super accurate. From the article, JVS is an I/O (or just input?) standard, not video standard.

The standard itself also covers video, it's just that the video part is little more than "use a regular VGA connector and one of these approved modes", so converting that part isn't the sort of thing one writes an article about.

It's just titled "Exploring JVS", but if clarification is needed "video" should be dropped out of the HN title.

If the title was just "JAMMA Standard", then that would suggest the original JAMMA standard from the 80s. JVS is its successor, and unfortunately has a confusing name.

from the title, I expected this to be a standard for video signals (like NTSC), and was excited to learn about a video standard I had never heard of.

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