Hey all, I'm writing a review of one of the Famicom's best shooters, Gradius 2 and would like to put in the details of how the game was achieved. I know the game uses mapper 25, the Konami VRC4 but I don't really know much about it except that like the MMC2 mapper 9 was used only for Punch-Out, VRC4 is exclusive to Gradius 2.
Can someone here explain to me what the chip allowed and why it was needed for Gradius II? I'm also interested to know if Gradius II could be ported to a more common mapper like Contra was for a possible NES reproduction.
Also, is the VRC4 related to the VRC6 in Akujamou Densetsu and VRC7 in Lagrange Point? If so, what game used VRC5 and what did that chip allow?
Thanks.
Looking at the pinout, it doesn't have the extra sound, the game is 128K and 128K ROM's, so there's no reason it couldn't be done on MMC3 unless it does something fancy....which it does! Read below.
So it offers the advantage over the MMC3 for instance is having 8K banks with only one fixed instead of two fixed, allowing for three other banks to be used for other stuff as far as I can tell. And probably the reason they did the new bank was to make it worthwhile using the chip, and to save costs on the games by not buying Nintendo's MMC3, which was probably more expensive to buy then this chip was to make. With the advantage of making their own mapper and adding a little other feature to it with the PRG-ROM switching in three 8KB chunks, it probably actually cheapened the price of the game and added more capabilities to it that they probably used to expand the game.
The advantages is has over MMC1 is having three pages of data versus two, too, and of course the scanline counter and 1KB CHR-ROM chunks compared to the MMC1's 4KB chunks.
And the VRC6 compared to the VRC4, the VRC6 is a bit different. From what I can tell on the pages on VRC6, bank $E000-$FFFF is fixed, Bank $8000-$BFFF is a 16KB bank, and bank $C000-$DFFF is a 8KB bank also switchable. It could be a disadvantage or advantage depending on how you use it, but IMO, It's an advantage. Although you won't have as many banks, The 16KB is big and could be used as the nametable read-off, the 8KB could be used for banking in game program subroutines, and the fixed bank would be the main game engine of course. Thats my opinion though. It depends on how the programmers take advantage of that difference weather it's good or bad, really. It maps the CHR-ROM into 1K banks just like the VRC4, so no advantages there. Also has a scanline counter, too, so same thing there.
Here's the NESDev wiki pages from what I just read and compared. Check for mistakes in my advantages and such....blah blah blah. Thats my though on it and what I got from the pages. Have fun. I hope I've been helpful and didn't get anything wrong, I've never used these mappers, this is just the information I can tell from the NESDev wiki.
http://wiki.nesdev.com/w/index.php/VRC4
http://wiki.nesdev.com/w/index.php/MMC3
http://wiki.nesdev.com/w/index.php/MMC1
http://wiki.nesdev.com/w/index.php/VRC6
thank you for the info, but I must confess that much of that is lost on me. my working knowledge of mappers is rather superficial - I know of them, but exact bank switching duties and such is confusing and I don't really understand much of it. Could you recommend a good source of info on the subject suitable for a beginner?
What I'm simply looking for here is a paragraph or so why Konami would have gone to the trouble to build a MMC specific to this one game. The game has digitized speech, but it also has very smooth animation unseen in just about any famicom shooter and large, complex bosses without flicker or slowdown.
To restate my question, which of any of these does the VRC4 mapper accomplish? I just can't help but shake the feeling that this mapper does something special like the MMC2 allows for those giant Punch-Out sprites. Or was it as you pointed out, simply a cost-cutting measure and the game very well could have been done on the much more common MMC3?
SatoshiMatrix wrote:
thank you for the info, but I must confess that much of that is lost on me. my working knowledge of mappers is rather superficial - I know of them, but exact bank switching duties and such is confusing and I don't really understand much of it. Could you recommend a good source of info on the subject suitable for a beginner?
What I'm simply looking for here is a paragraph or so why Konami would have gone to the trouble to build a MMC specific to this one game. The game has digitized speech, but it also has very smooth animation unseen in just about any famicom shooter and large, complex bosses without flicker or slowdown.
To restate my question, which of any of these does the VRC4 mapper accomplish? I just can't help but shake the feeling that this mapper does something special like the MMC2 allows for those giant Punch-Out sprites. Or was it as you pointed out, simply a cost-cutting measure and the game very well could have been done on the much more common MMC3?
The way they switch doesn't matter, it's just the fact that it does it and the game uses it to access more data in certain ways. and VRC6 and VRC4 use eight pages of graphics. MMC1 uses two, allowing for less graphics and animations from the MMC1. VRC4/6 use eight pages too, as you see from the Wiki page. VRC6 has two program banks, one big and one small and one fixed. Allowing for a decent amount of new data. VRC4 has three banks, allowing for the same amount of data as the VRC6, but smaller chunks. MMC3 has two small banks of 8KB PRG-ROM space to swap data in and out, but a decently big fixed bank of 16KB for the main game, which is also good, but can be achieved on those VRC mappers with an additional bank that can be changed, so it's an advantage that they probably used and wanted so they used their mapper instead. The digitized speech might even have used the extra 8KB register as a data pointer to the data for the voice, which is maybe another reason they wanted it, they probably used the other banks for game data and wanted the extra one to do that voice. Not saying that they designed it for that ONE voice, but they probably had something like that in mind.
The VRC4 does everything the MMC3 does, just allows for 8KB more data to be switched into program space, thats the simple way to say what it does.
Just because the MMC3 was more common doesn't mean it was cheaper. Nintendo charged for those mappers and thats probably a reason Konami made new ones, it was probably cheaper and they could do more if they wanted. When your buying in lots of 500,000 carts and stuff like that, it makes a difference and gets awful cheap to get your own chips made.
Ah.
So a way to think of it might be that the VRC4 has three banks of storage wherein to store the game's many one-time only boss sprites, boss patterns, stage layouts, etc? Gradius II does seem to avoid reusing sprites as most other shooters on the NES do.
That mixed with the cheaper costs of Konami producing their own chip rather than buying Nintendo's is why the VRC4 exists eh?
Sure. You can only see so much in the NES anyway, but the VRC4 in that game allows for it to be swapped out more...."customized" to what it needs to look at. The game probably use the two banks at once and is made to run off of 32K and use the extra 8K bank to switch in what it needs if it needs to be used like possibly the voice or more game data. That obviously is the reason, to get more data swapped in and out, but as for if it's for the voice, I'm not sure. It swaps the voice data in SOMETIME obviously, and of course it uses a bank to get there, but the extra 8KB bank might have made it easier to add.
I'm only guessing that the other reason they used it is it is cheaper, but thats just a guess, not fact. But I'd say it's pretty safe it's why they did it. Acclaim even used their own boards and cart shells in some of their games, probably because it was cheaper. No reason to go through all the trouble if it actually cost more and hurt the profit, right?
You seem to be mistaken. VRC4 is related to VRC2, and also is used in many more games than Gradius II. Lookup Bootgod's database to see all the other games using this mapper. To name a couple, Kid Dracula and Crisis Force use the same mapper as Gradius II.
Gradius II was attempted to be hacked to MMC3 in the past. From what I recall part of the problem why it would never work on MMC3 was sprite fetching from the opposite side of the pattern table breaking the MMC3 scanline counter. Now Konami could have got around this since they programmed it. I think the MMC3 limited CHR banking was able to be sorted out. So Konami could have probably brought the game to the US and Europe, as they did reprogram Parodius Da! to MMC3 for Europe which also used VRC4.
Really games don't "require" some mapper, but sometimes sacrifices have to be made when you can't do certain things.
But there's only one difference between VRC4 and VRC6, Doesn't that make them kinda related?
Konami was really smart about what they were doing. Maybe they knew about (or foreseen) the 'pirate' MMC1 and MMC3 chips. They were one of the few developers in a position to do something about it, they made their own ICs for all kinds of stuff. Lots of their arcade games had custom chips, some of them even run on a custom CPU.
You can find a bootleg copy of probably any major MMC1/MMC3 game. Konami stuff, not so much. Bootleggers would have been all over their stuff.
So it could cost more to make, but at the same time they could still make more money, because they knew they were that good.
They were a decently big arcade developer and did all that kinda of stuff normally so they probably weren't scared to go about making their own hardware. And that is true about the pirated stuff, didn't think of that! It was different enough to be protective but the same enough to have the same advantages....ahhh....it makes sense more-so now!
Konami VRC4 bootleg carts do exist. However it's possible they were too cost prohibitive to produce for the pirates and still make a good profit. I would imagine that MMC1 and MMC3 clones were more readily produced and also cheaper.
I'm not sure whether it's correct but from what I've read in the past (I've forgotten where, so don't count on this) only the three companies Konami, Namco and Sunsoft got approval from Nintendo to manufacture their own carts, and so they could do whatever design they liked on the casing and could develop their own mapper hardware. All games published by other companies (except unlicensed ones, obviously) needed to have Nintendo itself to manufacture the carts for them (or they must buy parts from Nintendo, something like that) and so they could only use whatever design (casing, mappers, etc.) Nintendo had to offer.
Nintendo went even more strict on their policies when they released the NES overseas (obviously, as seen from censorship, total number of games one could publish in a year, addition of the CIC, etc.) and demanded all publishers to hand over the game pak production job to Nintendo themselves (or buy parts from them blah bla bla). That's why Konami (and Ultra Games) had to change their games to standard Nintendo mappers when they're published for the NES.
Gilbert: If your first paragraph refers to the Famicom, then explain the Bandai mapper with EEPROM save and the Jaleco mapper.
Yeah I meant the Famicom (the NES was a big failure here). Like I mentioned I couldn't recall where I have read it so this could be incorrect, and according to
this page there seemed to be even more companies which produced their own mappers (Irem and Taito are also listed there), but it seemed that the restriction on NES games being forced to use Nintendo parts had some truth in it and it's not just because of the costs that the games had to have their mappers changed.
I know for a fact Acclaim made their own parts: boards, shells, possibly ROM's. And of course the lockout was bought from Nintendo no matter what.
Yeah I've read that too (from the incomplete mapper info in the Wiki at least), but it seems that besides the lockout chips they also used a variant of the MMC3 manufactured by themselves. So it's possible that they're on an agreement with Nintento to pay to use their parts and their circuits.
I seem to remember that NOA loosened up on some developers that continued to support the NES even after the Genesis had been out.
Hey guys, I wanted to revive this thread because I just saw retrozone now has an NES reproduction copy of Gradius II for sale.
http://www.retrousb.com/product_info.ph ... cts_id=112
How is this possible? Have they cloned the VRC4 somehow or this a port to some other mapper? I'm very eager to learn more about this. I would love to own Gradius II in physical format.
It's just a CPLD with the PowerPAK VRC4 fuse-map/verilog/whatever on it. So yes it's "cloned". If you want to own it on a cartridge, go ahead and buy it. It's nothing amazing (technically). It's nice certainly, but not surprising at all. Kid Dracula which also uses VRC4 is also available at RetroZone now and I recommend that game too.
I haven't heard about this. So if Gradius II has been cloned, is it possible to make a reproduction of Gradius II using an existing NES cart? I love retrozone don't get me wrong, but I'd rather not pay $45+shipping for the NES version of something I already have for the Famicom.
There is no NES cart that uses the VRC4, so you would have to use a pin converter + Famicom cart inside the NES cart case. Probably better to get a Famicom or clone and use the cart you have already.
You seem to be missing what I said. The PowerPAK lead to the development of the cloned hardware behavior of the VRC4. RetroZone (bunnyboy) can certainly take this information and put it on an appropriate CPLD, think of it as a programmable mapper chip. And ofcourse he has designed PCBs so thus making a game like Gradius II or Kid Dracula is not an issue.
However if you mean a cheap repro that people make by hacking up old game cartridges, that doesn't work for VRC4 since only Japanese games have that mapper. And those carts are more expensive and to use them in a NES you then need the converter.
Price wise the Gradius II on RetroZone is fairly competitive. Someone making a repro out of a converter and original famicom cart probably won't be able to do much better on price. The quality should be good.
But you say you already have the Famicom cartridge, so as he said you are better off playing it on a Famicom system or through a converter. If you wanted you could always put it into a NES cartridge yourself if you can make a nice label up.
bunnyboy, is there any performance difference between the new NES reproduction and the Famicom VRC4 original? For instance, slowdown, flicker, artifacting etc? Gradius II is one of the more impressive games for the Famicom.
Also I'm assuming this version is based on the original Famicom release and not the Graidus II AC rom hack that greatly improves it? To be honest that's the version I'd like to see. If you'd like I can email you a fully patched rom to take a look at if you are unaware of what I'm talking about.
What ROM hack is this? What does it improve?
I would guess that the cart on RetroZone is identical in operation to the Famicom original cart.
SatoshiMatrix wrote:
Also I'm assuming this version is based on the original Famicom release and not the Graidus II AC rom hack that greatly improves it? To be honest that's the version I'd like to see. If you'd like I can email you a fully patched rom to take a look at if you are unaware of what I'm talking about.
People have trouble getting that patch to work because they don't know that they need to patch it with this patch first:
http://www.geocities.jp/gx587/ips/fc_gr ... rev022.zip
Afterward, find and use the patch found on this blog:
http://messatu.wordpress.com/
and it should work.
Nestopia 1.40 won't play it but FCEUX and Nestopia 1.37 will.
RLError wrote:
Nestopia 1.40 won't play it
This is not a good sign if the ultimate goal is to put the game on a cart. Not that Nestopia is the ultimate almighty emulator or anything (it's pretty good though, from my own personal tests it has almost always behaved the most like the actual hardware), but if the original game works on it and the patched one doesn't, this is a sign that something is wrong. Even if it works on hardware, it might be just unstable enough to break under certain circumstances.
Does the hack work on the PowerPAK? Personally I'd rather have the original version (which I do) on a cartridge than some hack that tinkers with the graphics. But that is my personal opinion.
Yes it certainly does work on the Powerpak. The Gradius II AC graphics hack isn't as pronounced as the Gradius 1 hack that vastly improves the Famicom Gradius visually and structurally, but I still wholeheartedly recommend checking it out. The differences are all cosmetic, using new sprites, tilesets and color pallets that are much more similar to the arcade version of Gradius II.
Hey Bunnyboy, Happy New Year! Hoping you can confirm if you received the email I sent to your company site. I look forward to hearing from you. Thanks!
Sawate wrote:
Hi Bunnyboy,
Happy New Year. Sorry to be posting on this site. I sent you an email to your website regarding a discontinued item (Colecovision RetroKit). I was hoping you would be able to confirm if you received the email and advise if you are able to respond.
I look forward to hearing from you.
Thank you.
I guess I can see why bunnyboy has his contact policies the way he does. Creating an account to send a message in a post for an unrelated discontinued product. wow...
My guess is the answer is no to whatever question you emailed about.