Is there a way to mod the NES to somehow support CDS?

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

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lidnariq
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Re: Is there a way to mod the NES to somehow support CDS?

Post by lidnariq » Sun Oct 14, 2018 4:17 pm

I mean, the device is basically exactly this. Just on a 6502 instead of an 8088.

That web page says that PATA-to-SATA bridges work with it.

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Fisher
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Re: Is there a way to mod the NES to somehow support CDS?

Post by Fisher » Sun Oct 14, 2018 5:26 pm

That's great!
Very simple design, seems a little "universal" interface.
With different (specific) control software it would work on any other vintage system, correct?
Looks like a very nice project!

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Re: Is there a way to mod the NES to somehow support CDS?

Post by lidnariq » Sun Oct 14, 2018 5:32 pm

Anything that can be coaxed to look like the 8088's address/data bus, sure. That's not really much of a barrier.

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NeoTorpor
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Re: Is there a way to mod the NES to somehow support CDS?

Post by NeoTorpor » Wed Oct 31, 2018 1:07 pm

Thank you guys for your kind replies. I think a disc conection to the NES could help much to the nes homebrew scenario. Also it could be an extra aid to the flashcards, at least i still have the idea that a regular CD is cheaper than a flashcard. Thank you.
Harvest moon with swords is a terrific idea.

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Sumez
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Re: Is there a way to mod the NES to somehow support CDS?

Post by Sumez » Thu Nov 01, 2018 2:17 am

I'm not sure how it could help at all. Flashcards today are very cheap, fast, much more manageable, and allow you to randomly read and write data as you want.

It would be a cool gimmick/proof-of-concept though. But at the end of the day, it's not really much different from the already existing official disk system peripheral.

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Re: Is there a way to mod the NES to somehow support CDS?

Post by tepples » Thu Nov 01, 2018 5:09 am

Other than that blank CDs are still manufactured and blank Quick Disks aren't. And that a 128K PRG RAM and 32K CHR RAM would improve the mean time between loads compared to FDS specs.

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Fisher
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Re: Is there a way to mod the NES to somehow support CDS?

Post by Fisher » Thu Nov 01, 2018 8:26 am

Not wanting to be a crying baby, but unfortunatelly my reality is a bit different.
Flashcarts here costs an arm and leg.
A NES CD-ROM or any other option that could be built cheaper would be awesome to people like me.

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LightStruk
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Re: Is there a way to mod the NES to somehow support CDS?

Post by LightStruk » Thu Nov 01, 2018 8:47 am

A NES CD-ROM drive would need all of the things that the Famicom Disk System needs.
  1. A cartridge containing a BIOS for the NES CPU to talk to and to connect the drive to the console. The FDS BIOS initializes the drive and contains all of the routines games use to read/write disks, and a CD drive would need analogous routines to boot and to read compact discs.
  2. A connection to the drive through the cartridge. On the Famicom, the RAM Adapter (which plugs into the cartridge slot) has a cable leading to the drive, and we can safely assume that the planned and cancelled NES Disk System would have connected the disk drive to the NES expansion port and that the cartridge would have used the expansion port pins on the cartridge connector to communicate. A CD-ROM drive would have the exact same needs for the two systems.
  3. RAM in the cartridge adapter. The disk drive is slow compared to ROM, and a CD-ROM drive would be similarly slow. The BIOS routines copy data from the disk to RAM, and the console reads code and graphics from the RAM in the cartridge.
  4. An electrical interface to the drive. The FDS RAM Adapter has a custom chip inside of it, and one of its jobs is to speak the serial protocol that the drive understands to read and write disks. The Famicom talks to the chip, not the drive, using memory-mapped registers. For an IDE or SATA CD-ROM drive, the console would need some custom chip or FPGA to talk to the drive.
Would a NES CD-ROM drive be an interesting piece of hardware? Sure. Unfortunately, building it would be a huge undertaking, on the scale of creating the Famicom Disk System. It would take a team of software and hardware engineers more time than hobbyists have to spend.

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Nioreh
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Re: Is there a way to mod the NES to somehow support CDS?

Post by Nioreh » Thu Nov 01, 2018 8:50 am

Fisher wrote:Flashcarts here costs an arm and leg.
Where is "here", and why does it cost more there? both krikzz and retrousb sell worldwide as far as I know, for the same prices.

You can always get away dirt cheap by putting sockets in old carts, and use EPROMs/EEPROMs

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Re: Is there a way to mod the NES to somehow support CDS?

Post by tepples » Thu Nov 01, 2018 9:48 am

Nioreh wrote:
Fisher wrote:Flashcarts here costs an arm and leg.
Where is "here", and why does it cost more there?
Fisher, Zepper, and tokumaru live in the Federative Republic of Brazil, which imposes often prohibitive import tariffs on electronics as part of a strategy of import substitution industrialization.

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tokumaru
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Re: Is there a way to mod the NES to somehow support CDS?

Post by tokumaru » Thu Nov 01, 2018 10:18 am

"Here" is Brazil, where the USD->BRL exchange rate is extremely unfavorable to us, the average person's income is much lower, and import taxes are abusive. That being said, I had a great experience buying from krikzz a few years back. With Retro USB, not so much.

Krikzz's shipping fees were pretty cheap (US$5 or so), and packages very compact and inconspicuous, so I was never charged any taxes for any of the 5 or so flashcarts I bought from him. The packages also didn't take 3+ months to arrive, as is common with some international shipping methods. I believe it took from 20 to 30 days for them to get here.

The PowerPak I bough from Retro USB on the other hand was held by customs, since the full value was declared in the package, so I had to pay a significant amount of money in taxes. This was not Retro USB's fault, they were just doing things by the book, but unfortunately that makes it unfeasible for the average Brazilian to buy their products.

So, if you can save a bit of money, krikzz's store is a pretty good place to buy flash carts from, even in Brazil.

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Re: Is there a way to mod the NES to somehow support CDS?

Post by lidnariq » Thu Nov 01, 2018 11:30 am

Fisher wrote:A NES CD-ROM or any other option that could be built cheaper would be awesome to people like me.
LightStruk wrote:An electrical interface to the drive.
[...]building it would be a huge undertaking
Fortunately, it would NOT be a huge undertaking, but unfortunately, it would still be ridiculously expensive for our Brazilian colleagues.

The contemporary pirates already did this: they hijacked the FDS to produce both the Bung Game Doctor and Super Magic Card copiers, which supported some mapper that vaguely resembled GNROM or something that vaguely resembled VRC4.

But if we really wanted to do something along these lines, the first step would be for Fisher to look into what would be the cost of making his own XT-IDE card. There's some changes for an actual NES CDROM attachment, but that would be a good first step.

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koitsu
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Re: Is there a way to mod the NES to somehow support CDS?

Post by koitsu » Thu Nov 01, 2018 12:27 pm

lidnariq wrote:The contemporary pirates already did this: they hijacked the FDS to produce both the Bung Game Doctor and Super Magic Card copiers, which supported some mapper that vaguely resembled GNROM or something that vaguely resembled VRC4.
This would be mapper 6. There were several games that were hacked (modified) to use this mapper rather than their normal/stock mapper. GoodTools will label these ROMs by putting [hFFE] ("hacked FFE") in their filename.

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Re: Is there a way to mod the NES to somehow support CDS?

Post by nocash » Thu Nov 01, 2018 10:12 pm

Fisher wrote:Flashcarts here costs an arm and leg. A NES CD-ROM or any other option that could be built cheaper would be awesome to people like me.
What do you pay for a 8GB SD card, compared to a box of ten 800MB CDR's???
I don't think that the discs could be much cheaper.
I don't think that a disc drive with cdrom interface could be much cheaper than a tiny SD card socket with SPI bus interface.

I don't have a NES flashcart myself - but if they are pricy - then it's because they contain ROM and RAM and software and mapper emulation and a huge edge connector and a clumsy NES cart shell and because they are niche products, not because they contain flash memory. Using cdrom instead of flash won't reduce that costs at all. The whole idea about cdroms is even more unfit for mass production, it could work out only when offering the drives as an extra expensive crazy collectors limited edition hardware prototype project.

lidnariq
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Re: Is there a way to mod the NES to somehow support CDS?

Post by lidnariq » Thu Nov 01, 2018 11:20 pm

Yeah, if there were going to be an opportunity for cost reduction it would be specifically by restricting what games it were compatible with. I was vaguely trying to point that out by comparison to the contemporary pirate copier hardware, but didn't finish the thought.

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