Famicom/Dendy SRAM cartrige

80sFREAK · Post by **80sFREAK** » Sun Apr 01, 2012 2:00 am

How much is the fish?

Grumskiz · Post by **Grumskiz** » Sun Apr 01, 2012 2:53 am

Will it be possible for people who don't live in Russia to actually purchase this cart?
I saw the "RAM Factory" logo on the cart and I tried to buy their InviteSNES cartridge a while back, but I couldn't pay for it, because I would have needed to have a webmoney account which can only be made in Russia (or at least I think that was the case...I will not create an account there anyways). The website says payment with MasterCard is possible, but it is not available when you actually try to buy something there.

HardWareMan · Post by **HardWareMan** » Sun Apr 01, 2012 3:10 am

I'll try to answer most of your questions.

tokumaru wrote:Do you plan on selling these? I'm sure there would be a lot of interest!

Yes. After the basic user interface will be done.

tokumaru wrote:EDIT: Too bad that the video doesn't show anything interesting. No menu, it just jumps straight to the game. We don't get to see anything about the cart itself, other than it is able to run Bucky O'Hare.

Agree. That video was taken at early start for proof of concept. Later, I will make full demonstration video.

Bananmos wrote:What about hacking? Will Firmware/mappers be open-sourced and documented? If so, you have an immediate buyer here...

As I already said: you can make your own mapper. So, this mean you will get some info for development. Since I'm not only developer, I can't say about full open source right now. But I guarantee that you will get maximum info as it possible.

Bregalad wrote:Same here ! Good to know it wasn't an april fool.

No, it wasn't. It just happened.

tepples wrote:How well would an OpenStreetMap viewer run on the ARM? Is that ARM7 as in Game Boy Advance or ARMv7 as in modern smartphones?

Sorry for misunderstanding. We use STM32F107, it has Cortex-M3 core.

Jeroen wrote:I am very pleased with the fact that its designed for famicom. Using the powerpak with an adaptor works..but its not really elegant. Would be nice to just have a small cart plug in directly.

Yes, since we are "Oh, those russians!", we are used to play Dendy. Dendy is FC clone and it has 60 pin connector. NES has bigger cartrige, which can hold our cartrige and adaptor. So, everything justified.

Jeroen wrote:ps: if it wont cost too much a small dac for better "Extra" sound channel support representation would be nice...but I suppose you could go the powerpak route and just use 1 pin with pwm.

Yeah, we discussed that at early stage of development (at least VRC7 support). But temporary exclude this for simplified prototype. And yeas, we can do PWM DAC for it (FPGA pins its weight in gold).

Memblers wrote:Looks good. And wow, that's a lot of RAM.

We select RAM (actually SRAM, not DRAM, nor SDRAM and etc) for a write speed.

Grumskiz wrote:Will it be possible for people who don't live in Russia to actually purchase this cart?
I saw the "RAM Factory" logo on the cart and I tried to buy their InviteSNES cartridge a while back, but I couldn't pay for it, because I would have needed to have a webmoney account which can only be made in Russia (or at least I think that was the case...I will not create an account there anyways). The website says payment with MasterCard is possible, but it is not available when you actually try to buy something there.

That's are good question. We will try to resolve it as soon as it possible. For now you can cooperate with somebody, who can deal with it right now.

infiniteneslives · Post by **infiniteneslives** » Sun Apr 01, 2012 7:14 am

Looking good!

I've got some curiosity questions more to do with some of the technical details. For one I'm curious as to the interfacing done by the FPGA seems like 140 some I/O should be more than enough but you commented on I/O at a premium suggesting you're using most of them. I suppose once the technical details come out that would allow one to make their own mapper most of my queries will be answered...

Also how are you level shifting? The FPGA isn't 5V tolerant but it looks like you just have some resistors between the cart edge and FPGA pins? Am I missing something or does the dendy not operate at 5V? Just curious what your trick was here.

So is there not separate WRAM? I guess with the large amount of PRG RAM you can use the mapper to place the WRAM as a page or two of the same PRG RAM where the ROM image would exist?

Any plans or goals on a release date? If it's well documented I'd be interested in playing around with one.

HardWareMan · Post by **HardWareMan** » Sun Apr 01, 2012 9:18 am

infiniteneslives wrote:I've got some curiosity questions more to do with some of the technical details. For one I'm curious as to the interfacing done by the FPGA seems like 140 some I/O should be more than enough but you commented on I/O at a premium suggesting you're using most of them. I suppose once the technical details come out that would allow one to make their own mapper most of my queries will be answered...

All cart pins are routed to FPGA. I mean all, except power and sound. So, you can switch off internal 2KB CHR RAM, for example. Onboard SRAM are behind FPGA and did not accessable while FPGA are not configured. It give you maximum freedom for mapper routing.

infiniteneslives wrote:Also how are you level shifting? The FPGA isn't 5V tolerant but it looks like you just have some resistors between the cart edge and FPGA pins? Am I missing something or does the dendy not operate at 5V? Just curious what your trick was here.

Indeed, the Cyclone 2 has LVTTL/LVCMOS 3.3V. And Dendy, Famicom and NES - TTL/CMOS 5v. But, in practice, restrictions on the current through the resistance is sufficient.

infiniteneslives wrote:So is there not separate WRAM? I guess with the large amount of PRG RAM you can use the mapper to place the WRAM as a page or two of the same PRG RAM where the ROM image would exist?

You can do that, but only separate 32KBytes chip are battery backuped.

infiniteneslives wrote:Any plans or goals on a release date? If it's well documented I'd be interested in playing around with one.

There are tons of plans. :3 But most important are support at least over 90% NES ROMset. And we will aim to 100%.

tokumaru · Post by **tokumaru** » Sun Apr 01, 2012 10:12 am

HardWareMan wrote:You can do that, but only separate 32KBytes chip are battery backuped.

On the PowerPak, if the console is powered off by accident (e.g. the power goes out, someone trips on the power cord, etc.) you lose your progress, because you don't get a chance to write the SRAM contents back to the CF card. Did you add a battery to avoid this? How will the loading and saving of SRAM data work in your cart?

infiniteneslives wrote:But most important are support at least over 90% NES ROMset. And we will aim to 100%.

If your mappers are faithful to the originals I'm sure this will happen naturally. I just ask of you to not use "hacks" just to get games working, because that reduces the reliability of the cart as a development tool.

Most of us already own PowerPaks, and it's great to play games and all, but it's kinda lacking as a development unit. Your cart has the potential to be a great development tool, so please keep that in mind.

infiniteneslives · Post by **infiniteneslives** » Sun Apr 01, 2012 10:31 am

HardWareMan wrote:
infiniteneslives wrote:I've got some curiosity questions more to do with some of the technical details. For one I'm curious as to the interfacing done by the FPGA seems like 140 some I/O should be more than enough but you commented on I/O at a premium suggesting you're using most of them. I suppose once the technical details come out that would allow one to make their own mapper most of my queries will be answered...
All cart pins are routed to FPGA. I mean all, except power and sound. So, you can switch off internal 2KB CHR RAM, for example. Onboard SRAM are behind FPGA and did not accessable while FPGA are not configured. It give you maximum freedom for mapper routing.
infiniteneslives wrote:Also how are you level shifting? The FPGA isn't 5V tolerant but it looks like you just have some resistors between the cart edge and FPGA pins? Am I missing something or does the dendy not operate at 5V? Just curious what your trick was here.
Indeed, the Cyclone 2 has LVTTL/LVCMOS 3.3V. And Dendy, Famicom and NES - TTL/CMOS 5v. But, in practice, restrictions on the current through the resistance is sufficient.

Maybe it's just me, but I don't follow how a mere current limiting resistor saves the FPGA inputs from damage/accelerated wear. So if I'm not mistaken these are the DC limits of your device: http://www.altera.com/literature/hb/cyc ... i51005.pdf
According to that the absolute maximum input voltage is 4.0v @ 100% duty cycle and 4.2v at 50% duty cycle. Even with the current limiting resistors you've still got 5.0v present at the pins with the assumption that the input impedance of the pins is relatively high. Have you probed the pins to see what you actually have? The data sheet's warning would leave me a little concerned that this method of level shifting would limit life of the device:

"Conditions beyond those listed in this table cause permanent damage to a device. These are stress ratings only.
Functional operation at these levels or any other conditions beyond those specified in this chapter is not implied.
Additionally, device operation at the absolute maximum ratings for extended periods of time may have adverse
effect on the device reliability."

Is there something out there that shows how level shifting in this manner affects lifetime of the device? I'm not doubting that it doesn't work as is, but If you have more than 4.0V present on the pins I would expect that it won't survive over time...

I don't mean to be a naysayer, but it sounds like there is still time to toss in some level shifters if you decided to.

HardWareMan · Post by **HardWareMan** » Sun Apr 01, 2012 10:42 am

tokumaru wrote:Did you add a battery to avoid this? How will the loading and saving of SRAM data work in your cart?

This was done in order not to think about compulsory saving and loading WSRAM if you play just one saving game at time. Saving and loading WSRAM are going through the system menu.

tokumaru wrote:If your mappers are faithful to the originals I'm sure this will happen naturally. I just ask of you to not use "hacks" just to get games working, because that reduces the reliability of the cart as a development tool.

Our goal - the repetition of mappers in the original form, without any hacks and other such things. For example, documentation of MMC3 is very lame, even from Kevtris. I had to sit with an oscilloscope and logic analyzer to understand how it works. Now it works as it should and has been tested on several different games - everything works fine. Also, we will try to repeat the entire spectrum of Chinese mapers, but that is caring CaH4e3.

tokumaru wrote:Most of us already own PowerPaks, and it's great to play games and all, but it's kinda lacking as a development unit. Your cart has the potential to be a great development tool, so please keep that in mind.

I know. On the other hand, I want an autonomous cartridge All-In-One. With blackjack and hookers. 3

infiniteneslives wrote:Is there something out there that shows how level shifting in this manner affects lifetime of the device? I'm not doubting that it doesn't work as is, but If you have more than 4.0V present on the pins I would expect that it won't survive over time...

I don't mean to be a naysayer, but it sounds like there is still time to toss in some level shifters if you decided to.

I understand your concern. Many of you use Krikzz products and has no negative feedback. I mean non exUSSR users. I think that was enough time to testing in real conditions.

80sFREAK · Post by **80sFREAK** » Sun Apr 01, 2012 3:03 pm

2 HardWareMan could you please PM me to negotiate price, how to pay and shipping details

naI · Post by **naI** » Tue Apr 03, 2012 5:11 pm

Blimey, keep at it! This has the potential to surpass even the PowerPAK, especially if it runs on many clones!

TmEE · Post by **TmEE** » Wed Apr 04, 2012 2:25 am

I am certainly interested in this ^^

HardWareMan · Post by **HardWareMan** » Wed Apr 04, 2012 9:57 pm

All your questions can refer to the support forum in the English section.

B00daW · Post by **B00daW** » Sun Apr 15, 2012 11:59 am

Couldn't register on the forum. Said my gmail email address was banned for some reason.

I've got a question. What's the smallest amount of bankswitching enabled? PowerPak can do 4K at the least; which is why the PowerPak NSF player has to double its ROM space to compensate.

Post by **tepples** » Sun Apr 15, 2012 3:06 pm

B00daW wrote:Couldn't register on the forum. Said my gmail email address was banned for some reason.

A lot of niche forums appear to prefer e-mail accounts from domains owned by wired ISPs over free webmail provider domains because it's easier for a spammer to get away with using a disposable webmail account over one at an ISP domain that someone is presumably paying for.

Workaround: Register your own domain and put Google Apps on it.

HardWareMan · Post by **HardWareMan** » Sun Apr 15, 2012 7:50 pm

B00daW wrote:I've got a question. What's the smallest amount of bankswitching enabled? PowerPak can do 4K at the least; which is why the PowerPak NSF player has to double its ROM space to compensate.

Since all slot pins are goes thru FPGA, you can bankswitch every single byte of SRAM. But it will be expencive for FPGA.