Mapper Megaram 512kb Set Up on Yamaha CX5M

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By Soft Automaton

Rookie (26)

Soft Automaton's picture

21-04-2021, 03:43

Hi everyone!

I'm trying to get this cartridge running on my CX5M in the hopes of running some of the Yamaha Music ROMs.

I've been following a few threads here on setting up this cartridge but I've run into my own problems just and can't even seem to get started. I only get this error for now on boot:

Disk driver not found. System halted.

This occurs whether the SD has nextor.sys, command.com etc in it or not. I haven't been able to run FDISK either. It goes straight to that error so I never get to a command line to even begin. I have tried formatting to FAT16 on PC but I've read that this may not work. I've assumed that I have to format the SD card on the MSX first but no luck so far.

Anyone encounter this and know how I can get around it?

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By sdsnatcher73

Prophet (2220)

sdsnatcher73's picture

21-04-2021, 06:42

That sounds like something I’ve not come across here. Could you share a photo of the cartridge you have and some photos of the screen during boot (anything after the MSX 1.0 message upto and including the System Halted message).

By Manuel

Ascended (18125)

Manuel's picture

21-04-2021, 09:51

If this is a cartridge where you can switch the RAM between Mapper and MegaRAM, then I think you have an issue. For Nextor you need it to be on the Mapper switch (as Nextor needs 128kB RAM) and to run the ROM software you probably need it as MegaRAM. Although, perhaps the ROM can also be run from the Mapper, but that is to be tested.

Anyway, the question is what kind of cartridge you have exactly. It must be equiped with an MSX-DOS2/Nextor kernel ROM or disk ROM, I think.

By Soft Automaton

Rookie (26)

Soft Automaton's picture

21-04-2021, 22:02

As always - thank you for the quick reply here. It' greatly appreciated!

This is one of the open source / Fractal2000-style cartridges. It's come up in other threads too. In the photo I have the cartridge as well as two different SD/MicroSD cards I'm trying out (both 4GB, each with different partition size tests) Just so my photo doesn't create confusion, I am only focusing on one slot being used with one card just to get up and running. Yes this does have two switches on top as well. I'm annoyed that the label doesn't bother to mark what represents the jumper setting Smile

According to the various threads and pages I've read, this cartridge is supposed to work but the consensus is that it also lacks the necessary documentation so set up is a bit complicated and unclear. That said, I've tried this a few ways so far but what I have not been able to do yet is boot up the MSX and format it there. It shows only this:

I'm determined to get it to work and would really like to assemble a document that people can use. We seem to have several starting points but I could see this site eventually hosting the 'definitive' document that can help everyone. Given that I'm a step or two or three behind step 1, my troubleshooting may help it along too :)

Thank you!

By Manuel

Ascended (18125)

Manuel's picture

21-04-2021, 22:40

The flashROM is properly flashed?

By Pentarou

Champion (394)

Pentarou's picture

21-04-2021, 22:54

With the cart in front of you, (looking at the label) both switches have to be set to the right.
What happens if you boot with both SD slots empty?

By Soft Automaton

Rookie (26)

Soft Automaton's picture

21-04-2021, 23:32

@Manuel:
I've tried this a few different ways. The only first step I know of (that I've read here and elsewhere) is this:

'You need to format the SD via MSX'.

I tried this originally by doing a FAT16 format on PC, then putting nextor on it in the hopes of just getting started with set up. The screen caps are all I got as a result so when you say 'is the flashrom flashed' I don't know what that means in this context.

Right now I'm starting over from square one: blank SD, nothing on it. I'm assuming that any formatting done on the SD beforehand won't work and isn't a starting point.

@Pentarou:
I just tried several to respond to you:
- SD in slot 1 - both switches to the right: as above
- No SD in cartridge, switches to the left, as above
- No SD in cartridge, left switch to the right, right switch to the left, as above
- No SD in cartridge, left switch to the left, right switch to the right, as above

By Pentarou

Champion (394)

Pentarou's picture

21-04-2021, 23:33

If you are getting the message above (disk driver ... system halted) with no SD card inserted, you have an hardware problem either in your MSX or in the Cartridge.

By Soft Automaton

Rookie (26)

Soft Automaton's picture

21-04-2021, 23:44

My CX5M works fine with any other cartridge I have here. I have about 6 or 7 official Yamaha YRM cartridges as well as the expander slot for the rear. The CX5M demo cartridge, which I have, requires a second cartridge so I also know that both slots can work in conjunction with one another as well. It also boots on its own to MSX and will load the onboard synth module.

Are you saying that the cartridge's own ROM hasn't been installed properly (which, I guess, is what Manuel is asking)?

By Grauw

Ascended (10055)

Grauw's picture

21-04-2021, 23:55

From the message my interpretation would be: someone flashed an empty copy of the Nextor DiskROM on there without the embedded driver it needs to actually access the SD card. Possibly a manufacturer mistake, or if you got it from a 3rd party they might've attempted to flash the wrong DiskROM image.

I would contact the manufacturer if they can provide you with the correct DiskROM and flash tool for self-service, or return it for repair if it is not flashable on the MSX.

By Pentarou

Champion (394)

Pentarou's picture

21-04-2021, 23:58

It's an error coming from the Nextor Kernel, it happened to me while messing with slots/mapping on a machine, but if you are sure your machine is Ok then I guess that Grauw is right.
However I doubt is an incomplete Nextor without the driver, as the complete .bin file including Nextor and the driver can be downloaded from Belavenuto's Github repo.

You can flash the EEPROM with the correct file from the MSX, but you will need to boot to MSX DOS from some other media, at the very least you'll need an FDD or another SD/CF cartridge.

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