Difference between MSX SD Mapper & Megaram 512Kb and the MegaFlashRom with 512k?

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بواسطة engineer

Supporter (9)

صورة engineer

01-11-2018, 03:42

Heya guys!

Looking at purchasing the MFR but found this on ebay:

Trying to figure out what the difference between the two are. My Google research and looking on here have been unfruitful. Anyone have any experience with the one on ebay?


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بواسطة Grauw

Ascended (10824)

صورة Grauw

01-11-2018, 09:10

Looks a bit similar to Tecnobytes' IDE mapper 512K cart... Maybe they made it or friends of them did based on the same design?

بواسطة syn

Prophet (2135)

صورة syn

01-11-2018, 23:38

The cartridge you linked appears to be a sd card reader + memory mapper + megaram. More info about megaram here https://www.msx.org/wiki/Category:Megaram_Cartridges Perhaps ask the seller for info about the exact workings. Like whether you can use the megaram and memory mapper at same time or maybe you can just use either.

The megaflashrom scc+sd+mapper has sd reader, memory mapper, scc+ (and afaik a PSG) in fpga form and flashrom. More info about flash cartridges here https://www.msx.org/wiki/Category:Flash_Cartridges

بواسطة meits

Scribe (6577)

صورة meits

01-11-2018, 13:50

There is indeed a cloned PSG in the megaflashrom scc+sd(+mapper).

بواسطة Pencioner

Scribe (1613)

صورة Pencioner

01-11-2018, 13:52

Megaram and mapper can't be used simultaneously, there's hw switch. Btw, that's the same one as Tecnobytes' - the item description refers to Belavenuto Wink

بواسطة sdsnatcher73

Enlighted (4322)

صورة sdsnatcher73

02-11-2018, 04:15

It seems similar to https://www.8bits4ever.net/product-page/sd-512 but that is cheaper.

بواسطة edoz

Prophet (2501)

صورة edoz

02-11-2018, 06:22

Why not buy a gr8net? This has all fuctions included

بواسطة syn

Prophet (2135)

صورة syn

02-11-2018, 08:49

Sd-512 can be used in slot expander that's nice (though you would need to disable the mapper so you can only use the sd part)

بواسطة gdx

Enlighted (6449)

صورة gdx

02-11-2018, 09:09

I made a wiki page for this Interface. Megaram option is almost useless on many MSX1 and very limited on MSX with 64kB. 8bit4ever version seems better than Fratal2000 and cheaper.

بواسطة sd_snatcher

Prophet (3678)

صورة sd_snatcher

02-11-2018, 20:20

sdsnatcher73 wrote:

It seems similar to https://www.8bits4ever.net/product-page/sd-512 but that is cheaper.

They're not just similar, they're identical. Both of them use the open source hardware design created by Fabio Belavenuto.

The only relevant differences are:

- 8bits4ever changed the 2nd card slot to microSD and has huge switches
- 8bits4ever has black-painted screws to close the plastic shell. Fractal2000 uses screws with Zinc Yellow Bichromated finish to avoid rust in the long term
- The Brazilian models have a much more careful design of the PCB, drawn by none other than MSXpro

It's also important to notice that the SD-Mapper is fully compatible with all turbo Z80 machines, while the MFRSCC+ variants are not.

Grauw wrote:

Looks a bit similar to Tecnobytes' IDE mapper 512K cart... Maybe they made it or friends of them did based on the same design?

They might look similar, but are in fact very different designs with similar objectives.

They share in common the idea of having built-in slot expander and 512KB expansion.

But the disk interface itself is very different. Tecnobyte's IDE is a Sunrise IDE clone. OTOH, the SD-Mapper interface is an original design by Fabio Belavenuto.

As of yet, Tecnobytes doesn't produce any SD interface.

بواسطة sd_snatcher

Prophet (3678)

صورة sd_snatcher

03-11-2018, 15:31


I would like to politely ask you to stop including misinformation in the MSX-Wiki. If you're not sure, please open a thread beforehand here in the forums, ask questions, and only then proceed to create a reliable Wiki article.

You should have known that, given that the SD-Mapper is an open source hardware, many different people can build the same design, or build derivative designs. And all of them will have a lot of shared characteristics because of this.

It's not different from Linux distributions. You wouldn't go write reviews about a given Linux distribution just because other distribution has some characteristics you don't like.

For example:

  • You wrote that Fractal2000 is Fabio Belavenuto. But he's Daniel Ravazzi.
  • You posted incorrect pictures on the Wiki.
    • Fractal2000's SD interface has a black PCB with gold-plated contacts and not a blue PCB with tin-plated contacts.
    • Also, Fractal2000 never made SD-Mappers with crystal clear shells.
    • Fractal2000's SD-Mapper labels are professionally printed on glossy paper. The one featured in the label is inkjet printed on plain paper and has square markings in the corners.
  • Fractal2000's disk interface has gold-plated contacts too, and not tin-plated contacts as you wrote
  • You wrote about the MegaRAM feature form a very negative point of view, when in fact it's meant as a bonus for when the user's machine already has an internal memory mapper, since two mappers on the same machine would be less useful than a mapper and an external MegaRAM.
  • You wrote that the SD-Mapper supports up to 4GB cards, when in fact it supports SDHC cards up to 32GB.

IOW, there are many different people building SD-Mappers nowadays. These are some of the makers I know, but there are others: Fractal2000, PalMal, Luis Luca, 8bits4ever, etc.

SD-Mappers can be produced at a smaller cost than other mass storage interfaces because:

  • There are no project amortization costs, since Belavenuto and MSXpro kindly made the designs available for free
  • The design is very smart and was created under the same philosophy of the MSX: obtain the best possible results from very simple off-the-shelf components.

I know all of this can be quite confusing, and I already suggested Fractal2000 to produce his SD-Mappers with his own custom label (instead of the default label included with the project, that was also a contribution from a community member) to differentiate his interface from the others.

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