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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.

MSX – Using Sega Controllers

The MSX uses the same port as many older consoles, so one might be mistaken for thinking that any controller will work. Unfortunately, regardless of the fact that they are all DB-9 ports, the wiring is often different. Below I'll show how to build an adapter to hook up both a Megadrive and Master System controller to your MSX.

Sega Megadrive Button mapping

Standard Megadrive controllers have 3 action buttons. MSX only needs two, so we'll use B and C for buttons 1 and 2 respectively; the reason for this is a little complex. The Megadrive controllers have 4 buttons but only 3 wires to read the state. This means that one wire acts as the switch to read either A/Start as a pair or B/C. As that we can't switch between these without more work, we'll just use the second state and read B and C independently. There's further reading here for anyone who wants to know more.

Wiring up a Megadrive adapter

A quick note: If you have no requirement to use the Megadrive controller in a real megadrive again, follow the instructions here instead. Otherwise you'll need a male DB-9 plug, female DB-9 socket and some wire. The shorter you make the wires, the better. Too much play, without securing everything with glue or in a case, will cause instability and/or break your solder connections.

For the most part, all wires are straight through. The only exception is to wire Pin 9 of the male plug to pin 7 of the female plug. This routes button B on the megadrive controller to button 2 on the MSX.

I cheated and hot-glue-gunned them for stability. A better method would be to buy DB-9 plugs and sockets with housings. Or find two long and thin bolts to create a frame between the two.

Sega Master System Controller

The pinout of these controllers is slightly different (see here for a diagram); the buttons are actually backwards compared to B and C on the megadrive. Therefore we're going to build the same adapter above but route (from male to female) 9 to 6 and 6 to 7.

The result

The blobs rotate the right way when playing Puyo Puyo... that's all that matters!

Next... How to use that RGB port... Composite is terrible.

Roland Sound Canvas SC-55

Back in the day, my MIDI setting of choice was either Adlib, OPL3 or Sound Blaster FM. I only ever had a Sound Blaster 16 card and so never experienced any of the Sound Blaster 32/64/Awe Cards or external MIDI devices. Over the years since, I've learnt about MT-32 and wanted to try and find a real device. Unfortunately, they're neither cheap nor easy to find! A friend had also told me about the Roland Sound Canvas range and it seemed that these may be easier to find as there were more models released.

Stumbling across one...

I happened to be in Japan for a friend's wedding and, whilst travelling the countryside, scoured any recycle shops that I ventured past. It finally happened that, in one of the last shops in Kumamoto, I found a Roland Sound Canvas SC-55. It was 950 yen and was in the "Junk Corner".

I packed it into my suitcase, but researched it for the rest of the trip. One tidbit that I came across indicated that the internal battery had leakage issues (I anxiously wanted to check this, but didn't have the tools or the time.) The Sound Canvas Wikipedia page also pointed out that: "units without GM logo technically not GM compatible." Turns out mine didn't have the logo! Must be one of the first off the production line? I wonder if I'd even be able to play general games or only Sound Canvas games?

I then started getting lost in further articles describing the differences between the revisions of the SC-55. Nerdly Pleasures had a great article on the nuances here: First Generation Roland Sound Canvas Devices, which then lead to the Vogons forum: Apparently not all GS-only sc-55s are the same, some are GM. One poster noted that if you have an SC-55, you wont be disappointed as, regardless of the nuances, you'll still get quality music and games suited for the device will sound amazing.

Moisture Damage?

I noticed, when I first picked it up off the shelf, that the rear plugs were slightly oxidised. The top shell also had rust along the front edge. Opening it up saw that there was no physical damage on the board. Powering it up saw that the front panel buttons only wanted to work every-so-often. The first thing I did was find replacement microswitches from Jaycar who had a suitable (and really clicky!) substitute. Note that the replacement is half-width! Jaycar also had the full-square-shape types, but these had 4 pins and didn't match the PCB holes.

You can see above that column 3, row 4 had damage. I removed it and replaced it with the new slimline switch. Worked perfectly.

I ended up purchasing 16 of the half-width switches to replace all on the front panel.

Battery Leakage

Yup, coin-cell batteries leak too. When I first opened the box I saw that the battery was jammed in and corroding. This battery provides a trickle of power to persist storage of the current device configuration (panning, levels, key offsets, etc...) which is great if you're composing... but really, you want it to reset each time when playing games, so I was very happy to remove it.

You'll get a notice when the device powers on, but it's easily ignored.

Power Supply

The unit wants a standard DC jack with 9v at 500mA. Note that the polarity is the typical Japanese reverse! Positive on the outside.

Jaycar to the rescue yet again: The power supply had enough amps and a reversible plug on the end. I didn't even have to re-wire it. I am concerned though.. these adapters make it REALLY easy to plug in the power in the wrong way around!

Resetting/Testing

Before even trying composition software or games, I wanted to ensure that the device actually worked. 900 yen (along with the "not tested" label) meant that I could be in for a sad surprise when it chose to produce no sound. There is a demo mode on the device that plays two stored songs, so I attempted to get into this, after resetting the device.

To reset and enter GS mode, hold the left Instrument button and then hit power. Hold the right to reset (and enter) MT-32 emulation mode. Hold both to reset totally and return to GS.

The two sample songs only work in GS mode, so if you're in MT-32 mode, it'll first ask if you want to reset back to GS. This slightly confused me at the start as I thought the buttons were more damaged than first seemed; the Instrument buttons were meant to reset settings, not the Part buttons.

Anyway, to play the demo songs, hold down both Part buttons then power on the unit. You can select the song via either Part arrow and then hit the All button to play.

Using a MIDI keyboard

This 'just worked'. I'd received a midi cable with this keyboard and it was plugged from the 'out' of the keyboard to the 'in' on the front of the SC-55. Everything just worked, including all the controls on the keyboard. The keys are also perfectly pressure-sensitive... so whacking them harder really tested out the speakers!

MIDI Out via AWE64 Value

Now the fun was to begin. I pulled out the old PII-500 with an AWE64 Value sound card. The card has a whole lot of extra software and soft-synths to help with MIDI playback. This means that there's extra configuration required to get the MIDI-Out to actually work. By default, midi is routed into the AWE64 driver's 'soft synth switch' which then redirects and modifies the midi signals as configured.

I wanted none of this and set the output straight to the port. With the cables connected, I heard absolutely nothing. I mucked around with further settings... but had zero success. This 'SC-55 Howto' at Vogons indicates that output 'should just work'... not for me!

MIDI Out via SB32 PNP

This time I booted up my old 486 DX 2/66. Screamer has a nice audio setup application and allows you to test your configuration very quickly. Unfortunately, I couldn't get any midi-out at all. Is it my cable?

MIDI Out via Edirol UM-1EX

This device came with the keyboard and I'd forgotten I had it. A friend had told me they used their external midi devices in DOSBOX on new hardware, so I thought I'd give it a go. After switching off Windows 10 driver signing, I was able to get this installed on my main laptop. I then set DOSBOX to use the 'UM-1' device and loaded up Transport Tycoon.

Success! The audio sounded terrific! Of course, DOSBOX is emulation, so multi-tasking made the music slow down and sound hilarious... actually, that might just have been because the laptop was in power-saving mode and didn't want to spend all cycles on DOS emulation.

Joystick port on ISA controller card?

Nope, don't bother... it won't work! That joystick port is hardly good for one joystick with two buttons. You'll need a real soundcard with a standard gameport as they have the correct pins wired up.

MIDI-Out Cables

Back to the old PCs, it was time to work out why the MIDI wasn't sending out. The Edirol device above has nice lights on it to show that data is flowing, so I thought I'd try and add the same to my midi cable. There's a great diagram here that shows where the LEDs should be placed. Turns out they're just on the ground lines for each MIDI in and out.

Following the diagrams also available on Vogons, I realised that the resistors on the MIDI-OUT lines were way too high. 1.2kOhm vs the 220ohm listed in all diagrams I'd found. I quickly replaced these.

And then...

Well shit... Screamer Sound Setup just started sounding perfectly on port 330! Who would've thought you'd have to replace resistors inside a plug housing to get vintage midi signals to flow?

The Settlers intro sounded perfect as well.

What a steal for 900yen!