Author Topic: Which SD cards work with the current MD Menu  (Read 27062 times)

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Offline churkus

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Re: Which SD cards work with the current MD Menu
« Reply #30 on: March 22, 2010, 07:56:40 PM »
Thanks for the explanation ChillyWilly, it makes sense. I guess it was never designed to be handling sd i/o!. At least its faster and more convenient than loading a 32mbit file spanning 3 floppies on my magic drive was!.

Looking forward to LFN support!.

Offline ChillyWilly

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Re: Which SD cards work with the current MD Menu
« Reply #31 on: March 24, 2010, 12:56:17 PM »
Well, the flash carts were designed for a GBA/NDS. It's rather lucky that they also work as well as they do for the Genesis, SNES, and N64. If a clock source had been made from the MD Myth to the flash cart, we could have used the special cart feature that DMAs the SD card data into SRAM. That would have been given faster SD reading.

Offline tobio

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Re: Which SD cards work with the current MD Menu
« Reply #32 on: September 23, 2010, 05:41:07 PM »
Quote
LFN support is being added to the deluxe menu. And yes, SD cards are slower than flash. Right now, you get about 50 KB/sec transfer from the SD card. The theoretical raw transfer rate (discounting file system overhead) is a bit more than 100 KB/sec. The SD card has to be read by the CPU without any extra hardware support, which limits the speed. A 7.7MHz 68000 simply can't read an SD card that fast by itself.

I know nothing about programming, so forgive the ignorance behind this question, but would it be possible for faster loading if the menu ran on a 32x and utilized its coprocessors?

Offline Conle

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Re: Which SD cards work with the current MD Menu
« Reply #33 on: September 23, 2010, 07:05:41 PM »
I know nothing about programming, so forgive the ignorance behind this question, but would it be possible for faster loading if the menu ran on a 32x and utilized its coprocessors?

Yes , that is correct.CW plans to work on it sometime.But don't except speeds like 200KB/s.The psram speed limit is like 150KB/s.  ~sm-82.gif~.gif

Offline mic_

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Re: Which SD cards work with the current MD Menu
« Reply #34 on: September 23, 2010, 08:06:53 PM »
Yes , that is correct.CW plans to work on it sometime.But don't except speeds like 200KB/s.The psram speed limit is like 150KB/s.  ~sm-82.gif~.gif

150? Are you talking about some SD-specific case?  The SNES menu copies games from GBAC to PSRAM at about 400 kB/s.

Offline ChillyWilly

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Re: Which SD cards work with the current MD Menu
« Reply #35 on: September 23, 2010, 11:25:18 PM »
Remember that the fundamental speed limit is the rom access cycle time, which is a minimum of 8 cycles on the 32X, assuming no collisions with the 68000 or the other SH2. Given a 23 MHz clock rate, this means you get a maximum raw access speed of 23 / 8 / 2 ~ 1.4 MBytes/sec. So at least theoretically, we may be able to get some decent speed from a 32X version of the menu. I don't know if the MD Myth cart itself imposes some kind of speed limit on that, but given it works with 32X games without slow downs, I would guess not.

I guess I should probably do some tests to see how it actually works... maybe make a quick test version from the existing menu. Given the extra memory in the 32X compared to the MD, it should also have fewer limits as I don't have to try to squeeze things into 64KB.


Offline Conle

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Re: Which SD cards work with the current MD Menu
« Reply #36 on: September 24, 2010, 01:41:27 AM »
Are you talking about some SD-specific case? 

Yes.I haven't ever tried to do timing tests from mem->psram or sram->psram and i have no idea about the rom access cycle time to give an estimation  ~sm-57.gif~.gif
A good example of this is the N64 menu..

Offline phonedork

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Re: Which SD cards work with the current MD Menu
« Reply #37 on: November 04, 2010, 06:02:06 AM »
I have not been on this forum in a while and I was thinking about purchasing a Neo2SD for my Sega Neomyth cart. I bought a 1024 megabit cart and it when I formatted it for sega it only gave me half the storage it claimed. So I am wanting to get the Neo2SD version in order to use a real SD card instead. So my question is if I get this and say a 2gigabyte Kingston SD card I can load every game I could ever want on to this one device without buying another one of those 1024 megabit carts? If so..... then why would anyone ever want anything but the SD card version?  ???

Offline ChillyWilly

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Re: Which SD cards work with the current MD Menu
« Reply #38 on: November 04, 2010, 11:08:45 AM »
I have not been on this forum in a while and I was thinking about purchasing a Neo2SD for my Sega Neomyth cart. I bought a 1024 megabit cart and it when I formatted it for sega it only gave me half the storage it claimed. So I am wanting to get the Neo2SD version in order to use a real SD card instead. So my question is if I get this and say a 2gigabyte Kingston SD card I can load every game I could ever want on to this one device without buying another one of those 1024 megabit carts? If so..... then why would anyone ever want anything but the SD card version?  ???

The current PC client doesn't handle 1Gbit cards right, which is why it limits itself to 512Mbit until the issue is resolved.

As far as cards for the MD Myth, you really don't need more than the Neo2-SD. Once you have one of those, you can run whatever you want off SD or SDHC cards. The only things you NEED to put on the flash are SMS games (unless you have the latest V5 MD Myth hardware, then those can also be played off SD).

Offline smiff

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Re: Which SD cards work with the current MD Menu
« Reply #39 on: January 14, 2011, 07:46:26 PM »
SD CARD : EMTEC 2GB = FAIL (but works with NEO N64  Myth cart)

By the way, do you guys got any news about the correct handling of 1Gbit flash cart by "NEO2 Manager" software ?

Keep up this hard but excellent work !  ~sm-76.gif~.gif

Offline Conle

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Re: Which SD cards work with the current MD Menu
« Reply #40 on: January 14, 2011, 09:59:47 PM »
SD CARD : EMTEC 2GB = FAIL (but works with NEO N64  Myth cart)

Let me guess :
It is a "slow-card".The n64 menu detects this , and the disk io code triggers a small delay for each op....
The MD menu doesn't do this , so ..  ~sm-36.gif~  ~sm-36.gif~  ~sm-36.gif~

But yeah  ~sm-36.gif~ , we can implement this on the md menu aswell...but it is always recommended to use quality sdcs since you'll always get a penalty
on transfer speeds...and you don't want that.

~sm-36.gif~  ~sm-36.gif~   <-- those guys are ''noisy''..aren't they ?   ~sm-82.gif~.gif   ~sm-34.gif~ )
« Last Edit: January 14, 2011, 10:06:52 PM by Conle »

Offline panzeroceania

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Re: Which SD cards work with the current MD Menu
« Reply #41 on: April 23, 2011, 08:21:41 AM »
where can I buy the SD Card adapter for my Neo Myth Cart?

Offline ChillyWilly

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Re: Which SD cards work with the current MD Menu
« Reply #42 on: April 23, 2011, 09:21:05 AM »
where can I buy the SD Card adapter for my Neo Myth Cart?

You want the Neo2-SD: http://www.ic2005.com/shop/product.php?productid=41&cat=5&page=1

Unless you plan to get the N64 Myth at some point, then you'd probably want to get the Neo2-Pro: http://www.ic2005.com/shop/product.php?productid=119&cat=5&page=1

The Neo2-Pro works for the MD Myth as well, but doesn't have any advantage over the Neo2-SD ON THE MD MYTH. You want the pro for the N64 Myth as it allows you to load games up to 32MBytes while the Neo2-SD is limited to 16MBytes.

Offline joyeux

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Re: Which SD cards work with the current MD Menu
« Reply #43 on: February 25, 2013, 11:21:49 PM »
Please add to FAIL list:

Sandisk 4GB MicroSDHC Class 4 (with adapter)

NEO3-SD may corrupt written data in the SDHC card, making the card unreadable in Windows.

EDIT:
Please add to WORKS list Smart Modular Technologies 4GB Micro SDHC (with adapter). Works flawlessly.
« Last Edit: March 01, 2013, 07:38:29 PM by joyeux »