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MSX – MegaFlashROM SCC+ SD

The MegaFlashROM SCC+ SD, by Manuel Pazos, is the ultimate cartridge for the MSX. I acquired this and my Sony Hit-Bit F1XD a while ago and finally found time to actually use it!

Basic Concept

The cartridge emulates the A: and B: drives on your MSX. This means that previous A: and B: physical drives will be disabled and ROM/DSK files will be used instead. The cartridge has it's own ROM (kernel.dat) which loads you into the Nextor operating system.

From the shop, your cartridge will be ready to go. Grab a small (1gb? 2gb?) microSD card and put it in, then load up your MSX with the cartridge inserted. You should be at the Nextor prompt and you can then follow instructions as per ¡VAPF!'s brilliant tutorial here. You'll end up partitioning and formatting the SD. From there, you can put it into your computer and copy your DSKs and ROMs over.

The cartridge already has firmware in it containing an enhanced version of MSX-DOS bundled with tools for loading disk images. It also includes Multimente, a file browser which makes loading files very easy! You merely have to hit enter on the disk image you wish to load into ROM.

Above you can see the initial A: disk. Hit the L key to switch disks: Type B and press enter. This is now your SD card. Select your ROM image and you'll get the screen below that Nextor has chained it in to the boot process.

Once chained, you can reset the machine and the cartridge will act as if it's the original game cartridge/disk. Reboot away...

You're next reboot will mention that a ROM Disk was found and then you'll get weird things... they're called games:

This game really needs a post to itself... I'll get back to that... meanwhile, here's the intro.

To unload the ROM, you'll need to know the short-cut keys. Note that the commands to unload images are entirely dependent on how you loaded the files in the first place!

Forgetting how to use it

I had received this cartridge quite a while ago. I quickly configured a 32gb MicroSD (I created a 4GB partition on it) and got a game running. I then packed everything away and quickly forgot all the knowledge required to use an MSX computer. I also never learnt correctly how to unload a game which meant, this time around, that I was stuck with a flash cartridge that continued to load a ROM of which I didn't want to play.

Not knowing how to clear it, I chose all the menu options in the 'Recovery' Menu. You can access this menu by holding the up cursor key at boot. It turns out that, when using the MultiMente (we'll talk more about this below), the ROM is actually tied into the Nextor operating system and not the cartridge boot. Clearing the settings in Recovery really just wiped the cartridge when I didn't need to.

At this point I was stuck... I needed to start from scratch and work out how to unload images. Fortunately, the author of the cartridge responded to emails almost instantaneously! Thanks Manuel!

Unloading ROMs and DSKs

There's two ways to load a ROM: You either flashed a ROM image over the entire Cartridge, or you chain-loaded a disk image from Multimente. Both methods have different ways of unloading the images.

If you've overwritten the ROM, you can hold the UP arrow key when booting the machine. Straight after your MSX logo has appeared you should get the recovery menu. From here, you can use F1 to clear the ROM in memory. (F2 and F3 will clear other portions of the cartridge, if you've done that then see below.)

If you've loaded a DSK file from Multimente, then you need to hold down 0 during the boot process. This will skip loading the disk and bring you back to Multimente. You can then stop the disk from chain-loading by deleting NEXT_DSK.DAT from the SD card. You can also do this file when the SD card is in your PC.

Restoring the Flash Cartridge

If you've done unrecoverable damage to the ROM images, then you can restore the whole thing. Chances are good that, with the cartridge inserted, you'll just get the following BASIC prompt...

Copy the Kernel Image to the base folder of your SD card (note that I had issues with a 32gb card and had to use a 1gb card to make this work...) and then choose F4 from the boot menu.

It'll tick through a counter and then bring you back to the menu when done. Reboot your MSX and the cartridge should bring you back to Multimente. If you see your game loading instead, then Nextor is still chain-loading and you'll need to hold down 0 as per above.

Update: It turns out there's a newer version of the Recovery ROM to allow support for 32gb SD Cards. Grab it from here and then flash it by running OPFXSD RECOVERY.ROM /i34 from the Command Line.

Ok, What games should I play?

Bubble Bobble. A-Ressha-De-Ikou. And the rest of them...

MSX – VGA/HDMI Output

My Sony Hit Bit F1-XD either outputs Composite video via standard RCA plugs or 15khz RGB video via an 8-pin DIN cable. Video quality is poor (at best) via Composite on my LCD, so I purchased an RGB to SCART cable from eBay. Due to this being Australia, I also needed to convert this new SCART plug to something more useful.

The first two failures...

I can guarantee that the following two adapters just don't work. They seem to only convert standard composite video from the SCART and disregard the RGB signals. The worst part is that I able to randomly get video from them... Plugging/unplugging and powering-on/powering-off the devices had the MSX display briefly (but never correctly) on my TV and I therefore kept trying to get them going. In the end they are just not the right components.

Note: It seems that, after reading and learning of the GBS8200 below, the CSYNC from these old consoles is 4.6v which is too high for standard converter chipsets. These devices may well work correctly if you put a 680ohm resistor in-line.

If you see anything like these on eBay, then be very careful. Most of them are knock-offs and you can't be sure that they will work with your retro device that outputs RGB.

Just quickly, here's the composite quality...

For all future references, this is what you'll have to deal with on a new TV if you're using the composite input.

Now onto the conversion!

SDV500

This SDV500 adapter found on eBay, although looking frighteningly similar to the first one above, does work. It even mentions in the description that it'll support the 15khz RGB signal that my MSX (and Amiga 1200, now that I think of it) outputs. I asked the seller, prior to purchase, how his product differs from the first one above and he told me that he couldn't guarantee what the one above contains internally; whereas his was guaranteed to work.

It arrived and looked slightly different to my first chinese-knock-off. I hooked it all together and crossed my fingers.

Well ... YES!

Extremely crispy. Acrually, there's a weird 'sparkle' to it where the pixels seem a little noisy... I'm not fussed. The output is great.

The best part about this upscaling is the ability to read filenames in multimente.

GBS8200

Work in progress...
This GBS8200 (also found on eBay) is really meant for arcade machines, but works perfectly for us as well. I purchased a 8-pin DIN plug from Jaycar and made my own RGB->VGA cable to connect everything up.

Ian Stedman has written up a huge post on this device, specifically mentioning how to enhance it. I'll need to mod it to support SCART. An LM1881 can be found on eBay.

I'll get back to this component when I've tested it out.