SD2SNES implements Byuu's MSU1

**djelaba** · 06-02-2011

Ikari is adding uPD77C25 support (DSP), with each variant (DSP 1 to 4), as well as BSX-support, and S-RTC chip.
But SA-1 and Super FX will never be supported...

**Greg2600** · 06-02-2011

Originally Posted by djelaba

Ikari is adding uPD77C25 support (DSP), with each variant (DSP 1 to 4), as well as BSX-support, and S-RTC chip.
But SA-1 and Super FX will never be supported...

Ah, thanks for the info. Those he's doing are only a half dozen games more than the just adding DSP-1 to a PowerPak or Everdrive.

**derekb** · 06-02-2011

every bit counts

**MottZilla** · 06-03-2011

Originally Posted by Greg2600

As for Star Fox 2, I was told pretty firmly that $100 is about as low as one could go due to the amount of labor required to do the job.

This is not true at all. It's no different than making any other "repro" bootleg. You remove the MaskROM and connect a programmable ROM (typically EPROM) and you're done. The only difference is Super FX uses SOIC type MaskROMs which are much smaller and are not as easy to solder and desolder as typical DIP chips. There is no reason "$100 is as low as one could go". That's just a number pulled out of one's ass. Now don't get me wrong, if they want to charge that much for their labor that is fine. But don't act as though it is heart surgery. Star Fox 2 costs maybe as low as $10 to make a bootleg of. The primary cost is the sacrificial Super FX cartridge. If you get that cheap enough, the only other cost is the EPROM or FlashROM which can also be had for very cheap used. That leaves printing up a label which the cost is pretty low for that.

The fact is if you buy a Star Fox 2 bootleg for $100 you are helping someone make one hell of a profit.

Originally Posted by derekb

Presumably they've got an eprom wired into the original rom location from a superfx cart. Though I recall reading a lengthy discussion as to which superfx cart was the best to use on a Star Fox 2 repro based on clock differences between FX chips. I believe the winter gold or whatever one was considered ideal, followed by stunt race fx, I could be mistaken? someone probably knows what i'm talking about / better

You're right, different Super FX cartridges have differences in their clock speed and how they are set up. Some cartridges (maybe all) have a register which can switch between 10.5mhz and 21mhz. Some or all may have a particular initial setting or maybe a hard wired one. I'm not entirely sure. I know there is a register related to the clock speed but not if some carts ignore it. Doom is known to run at the higher 21mhz. However if you make Star Fox 2 using it, you will not be able to save data. This is why Stunt Race FX is preferred since it does have SRAM and a battery. Winter Gold I think was only released in PAL regions but I've heard it is similar to Stunt Race FX.

Really the reason people charge so much for a bootleg of SF2 is because most people lack the skills and experience and those that have the skills and experience to do it probably have better things to do than hock bootlegs.

**derekb** · 06-04-2011

well, fwiw it really is pretty involved to wire up the eprom as well, I can solder pretty well but wiring that up is daunting to me

**MottZilla** · 06-04-2011

It's not that hard. It's just tedious and takes some time. And you need to use the correct soldering iron, not some big monster that is overpowered and going to melt everything.

**Greg2600** · 06-04-2011

Well, I brought that $100 price up on digitalpress forum and was subsequently knocked for saying it was too high, with several people saying it requires a lot of labor.

**derekb** · 06-05-2011

well, if everyone thinks the price is too high maybe someone should step up and produce them for less :p

**MottZilla** · 06-05-2011

Originally Posted by Greg2600

Well, I brought that $100 price up on digitalpress forum and was subsequently knocked for saying it was too high, with several people saying it requires a lot of labor.

Just because people who justify the sale of bootlegs harp on you for saying it costs too much doesn't mean they are right. Like I said, you can ask whatever you want for your labor. But the truth is the parts involved cost a tiny fraction of $100 and I wonder if they have the nerve to charge for shipping at that price?

Again, you can get an EPROM with StarFox 2 on it for less than $10, maybe just $5. Then you need Doom or Stunt Race FX which you could get for as little as $5. Next you need a soldering iron, desoldering pump or braid or something, wire, and solder. These are not expensive at all and can be used for many other projects. You'll probably want a label, so you'll need paper and a printer, again not exactly expensive.

So if you want to pay someone something like a rate of $80 an hour for their work go right ahead. It probably doesn't even take them an hour if they have done many of them.

**l_oliveira** · 06-09-2011

When I made my Starfox2 repro cart (for personal use) I used Yoshi's Island as donor cart just because it had battery backed SRAM and SGU2. It even have the proper pads for the bigger RAM chip SF2 requires (I used an 128KB chip instead of 64KB it uses). An minor modification was required (connect A15 for the SRAM address to the GSU2 chip) and I was able to use A16 of the SRAM to create two banks, allowing me to put two games on the cart.

So, the best cart to make SF2 is not Stunt Race FX (GSU1 with 64KB) but Yoshi's Island (GSU2 but with 32KB SRAM)... :shrug:

Of course it's easier to use Stunt Race FX, but you will end with an underclocked FX coprocessor... :dammit:

**derekb** · 06-09-2011

If I recall correctly some people replaced the crystal in their stunt race fx cart? I could be mistaken, it was a really lengthy discussion on another forum about ideal carts, if I had the link I'd paste it

**Teancum** · 06-12-2011

As much as people will complain about the price of a SF2 cart (lol I'm not paying a $100 for one) It doesn't really make any difference until some one sells them for less. You can only buy stuff for the price people are willing to sell for and you can only sell stuff for what people are willing to pay. IF everyone stops buying $100 SF2 carts then either the price will come down or they will disappear.

**Alchy** · 06-12-2011

Originally Posted by l_oliveira

Of course it's easier to use Stunt Race FX

Also a lot cheaper. Yoshi's Island is £15 or so on ebay.

When you say "underclocked FX" do you mean that the game lags if you use a Stunt Race cart? Or that the chip is simply running at a lower clockrate than it should be (which presumably isn't much of an issue)?

**MottZilla** · 06-13-2011

I'm not sure if Stunt Race FX can't do 21mhz mode. From what I've heard it is GSU-1 which SHOULD be capable of 21mhz mode. GSU-2 (Doom, Yoshi's Island) only increases the maximum amount of ROM from 8 to 16 megabits. Star Fox (Mario chip) can't do High Speed 21mhz mode though.

I haven't tried building my own Star Fox 2 carts on both Doom and Stunt Race FX to try comparing them. It would be something good for someone to make a video of comparing them if there is a difference.

**derekb** · 06-15-2011

http://www.liquidninjas.com/bbs/show...threadid=13388

that is the thread I previously mentioned, there is alot of discussion in there about which cart board is the best for SF2, you may want to look through that MottZilla, it's beena while so I cant even remember exactly what they decided

**MottZilla** · 06-16-2011

Reading through that thread I noticed a bunch of misinformation. For example one person used a term that they thought Star Fox 2 didn't run any better on 'Super FX2' because it wasn't 'using both cores'. This shows a lack of understanding.

Personally I think people think it's supposed to run smoother thanks to popular emulators like ZSNES not emulating Super FX cache delays which results in games performing better in emulation than on real hardware.

I did check and the CLSR register ($3039) bit 0 controls the clock rate. 0 = 10.5mhz, 1 = 21mhz. It was not clear whether or not GSU-1 or GSU-2 could both enable 21mhz mode. Someone also mentioned seeing a GSU-2 in a Stunt Race FX cartridge. So it's possible some later produced cartridges switched to the GSU-2 when they stopped producing the GSU-1.

**derekb** · 06-18-2011

I believe that thread started around the initial 'lets build starfox carts!' craze, so it kinda had alot of speculation involved from the get-go

anyone happen to know what setup the main repro maker uses?

**APE** · 06-18-2011

Originally Posted by derekb

I believe that thread started around the initial 'lets build starfox carts!' craze, so it kinda had alot of speculation involved from the get-go

anyone happen to know what setup the main repro maker uses?

Winter Gold seemed to be a pretty good starting point but off the top of my head I don't recall why. I'd imagine each repro type has their own personal picks for what they use and reasons as to why.

Stunt Race FX can be overclocked judging by the fact that I found a Stunt Race FX cart inside a box with tantalum capacitors and a crystal in a Digi-Key bag labeled "Super FX o/c stuffs". At the very least I'm assuming I thought I could give it a shot apparently.

**link83** · 06-18-2011

Originally Posted by MottZilla

Reading through that thread I noticed a bunch of misinformation. For example one person used a term that they thought Star Fox 2 didn't run any better on 'Super FX2' because it wasn't 'using both cores'. This shows a lack of understanding.

Personally I think people think it's supposed to run smoother thanks to popular emulators like ZSNES not emulating Super FX cache delays which results in games performing better in emulation than on real hardware.

I did check and the CLSR register ($3039) bit 0 controls the clock rate. 0 = 10.5mhz, 1 = 21mhz. It was not clear whether or not GSU-1 or GSU-2 could both enable 21mhz mode. Someone also mentioned seeing a GSU-2 in a Stunt Race FX cartridge. So it's possible some later produced cartridges switched to the GSU-2 when they stopped producing the GSU-1.

So was Star Fox 2 intended to run with a 10.5mhz or 21mhz clock? It doesn't seem to be clear if it does or not, since it runs fine in both modes.

I know many Super FX games run with a slightly better framerate on 21mhz, but if the game was not designed to really use 21mhz then there doesn't appear to be that much benefit in using a game with a GSU-2?

Also there seems to be a lot of confusion about MARIO CHIP 1, GSU-1 and GSU-2, with many people believing that the GSU-2 is a 'Super FX 2', which appears to be a completely made up name which Nintendo never used? Isn't the GSU-2 just a GSU-1 that can address more ROM? and if so might there be a high/low pin on the GSU-1/GSU-2 that can be used to select the default clock rate?