Sega CDX FAQ by Shakey_Jake33

Version: 1.0 | Updated: 07/02/03 | Printable Version

                            Sega Genesis CDX/Multi-Mega FAQ
                                   By Shakey_Jake33
                               Released 2rd July 2003
                                     Version 1.0
                       Best Read in Notepad with Wordwrap ENABLED

This may seem like an obscure unit to cover in this day and age, but let me
About a month ago, I was lucky enough to pick up an unboxed American Genesis
CDX for 99 (I live in Britain).  Now it had always been a dream of mine since
1994 to own a Multi-Mega, so as you can imagine, I was excited.
On searching the net however, I found there was very few places to read up
about this unit.  Suprising really, given what it is.  Aside from Barry W.
Cantin's superb SegaCD FAQ, there was little on the internet about the unit,
and I felt I must fill the void.  Informative tho the aforementioned FAQ was, I
feel one tailored for the CDX itself would be best.  Not many people may own
one, but given it's collectors item status, those who buy one will want to read
up on it I'm sure.

Now, in this guide, the MegaDrive/Genesis will always be refered to as the
'Genesis', the MegaCD/SegaCD will be refered to as the SegaCD, and the
CDX/Muiti-Mega will be refered to as the CDX.
I'm sure I speak for every European Sega gamer that I cringe when I hear the
MegaDrive refered to as a Genesis... it's a MegaDrive dammit, why do you
Americans have to be different? (lol).  But all the same, Genesis seems to be
the most widespread name on the internet, so I feel I must fit in with the
current standard.  Plus my CDX is American, so it helps for consistancy at my

Usual FAQ guidelines apply, no copying my work and claiming it as yours, I'd
prefer credit it given to me when due.  I don't care if people have it on their
site, in fact I endorse, it, spread the knowledge!  Just don't go changing
And with my end of the bargin, this information is not all mine (bar the
obvious which can be made by simply owning one).  A lot of the information is
picked up from Barry W. Cantin's excellent SegaCD FAQ, which you should all go
check out at GameFAQ's ASAP,  a lot of it I found on by reading the SegaXtreme
forums, and some at the GameFAQ's forums.
I can't remember indivudual member names I'm afraid, but I do give credit to
these people...  I will not be so rash as to claim this as all my own research
because that's just not fair.  Full respect and credit to the original sources.
Now, on with the FAQ...


1. CDX Questions

1.1 What is the CDX?
1.2 What is the MultiMega?
1.3 What new features does the CDX Provide?
1.4 So what actually does my CDX run?
1.5 Does it really run from Batteries?
1.6 What is the difference between this and the WonderMega?
1.7 How long was it under production for?
1.8 Are there any compatibility problems?
1.9 What CD Player functions are there?

2. Import Questions

2.1 Is the CDX region protected?
2.2 How do I play import Genesis games?
2.3 How do I play import SegaCD games?
2.4 Does it play chiplocked games?
2.5 Can the protection be bi-passed through hardware?
2.6 I have an import machine, do I need a stepdown?

3. Utility Questions

3.1 Does the 32X work with the unit?
3.2 If so, does it play 32XCD games?
3.3 Do the Master System converters work with the unit?
3.4 Does the Action Replay/Game Genie work?
3.5 Are there any incompatible utilities at all?

4. Thanks and Contacts

Go look...

CDX Questions

1.1 What is the CDX?

The Sega Genesis CDX (a.k.a Multi-Mega) is a Genesis and SegaCD in one unit,
with the added function of operating as a personal CD player, running off of
betteries (althought a power adaptor can be used for this also, it won't
provide much help in a car...).  It also, like the SegaCD, is compatible with
CD-G discs.
It is about as large as a standard personal CD player, with the only extra size
being to fit the Genesis cartridge slot.  It's also slightly heavier, but this
is understandable.
The unit takes a standard Genesis 2 power adaptor, which fits into the top of
the unit.  It also uses the Genesis 2 style A/V leads, which annoyingly resides
in the right of the machine, meaning you have to have a 2 inch gap at that one
side.  No biggie.
The left side of the unit has 3 features, a headphones socket, which works for
both CD's and games, along with a volume control.  This was heavily missed with
the Genesis 2, so this is a welcome addition.  There is also a line out socket
for hooking up to a hi-fi system.
The front of the unit has controller port 1 on the far left, a power button in
the middle, and controller port 2 on the far right.  This spacing looks nice,
if causing annoyances with the 4-way multitap, but more on that later.
Above this there are the unit controls.  From left to right we have a small
Open button to open the CD lid, a 'backwards button' followed by a forwards
button, both of course for CD playback, a small LCD screen in the middle
displaying the current track number (including which audio track it's currently
playing in-game), as well as displaying 'Access' when it's loading.  Following
this we have a Play/Pause button and a Stop button, again both for CD playback,
and a small blue reset button.
The unit itself apparently came packaged with a 6-button controller, a power
adaptor, a Red-White-Yellow style A/V cable (probably an RF cable in Europe),
along with the Sega Classics 5in1 pack (which contained Streets of Rage,
Columns, Super Monaco GP, The Revenge of Shinobi and Golden Axe), Sonic CD and
Ecco CD.
Overall, this unit is the Sega gamer's dream.  It's portable, it can run all
your Genesis and SegaCD games, it will play your Master System games with the
adaptor, it *does* actually work with the 32X, and it can be used as a CD
Player to boot.  Very nice.

1.2 What is the MultiMega?

Multi-Mega is the European name for the unit.  Being a Brit, and being used to
the name MegaDrive, I perfer this name, but seeing as my unit is American, I'm
used to calling it this.
It's easy to confuse the name 'CDX' with the import playing device of the same
name mind.

1.3 What new features does the CDX Provide?

The most obvious advantage is it's portability... it's much smaller than the
Genesis 2, comparable to the Genesis 3... so you can take the thing on holiday.
 It would be quite a trek to manage to cart your Genesis and SegaCD anywhere
Besides this, there's the headphones and line out ports, which Genesis 2 owners
were unlucky enough to not get on the main unit.  The CD-Rom seems to be
faster, loading times are generally far shorter than with the SegaCD.  It also
uses a later bios revision (version 2.21).  I do remember reading that this
bios revision also helps speed up CD accessing times.

1.4 So what actually does my CDX run?

It runs the following -

-All Non-Chiplocked American and European Genesis games.
-Chiplocked American and European Genesis games, region depending.
-SegaCD games, region depending. Including CDR's.
-Audio CD's, both standard and small size.
-CD-G and CD-EG discs.

No it does not play VCD's, nor photoCD's.
The cartridge slot is not big enough for Japanese games.
The Genesis portion seems to be similar to the Genesis 2 for compatibility.

1.5 Does it really run from Batteries?

The CD player portion does yes.  It runs on 2x AA batteries, and actually lasts
a very long time, a rarity in the era.
You need a power supply for the Genesis and SegaCD, but given how much these
things probably guzzle, this is understandable.  Anywhere with a TV should have
a plug socket anyway.

1.6 What is the difference between this and the WonderMega?

On paper, the WonderMega (a.k.a X'Eye) is probably better.  The WonderMega
features a MIDI connection, ability to use 5' CD's, among other features.
It was about as big as a Genesis 2 with a SegaCD2 mind, so portability was not
really an option with the WonderMega.
The whole appeal of the CDX was it's portability, and the WonderMega is
rendered a little pointless when it's the same size as both units combined, and
more expensive too.
It's also harder to find, being made my JVC as opposed to Sega.
The WonderMega is probably better, but unless you have a real need for MIDI,
then you'd be just as well off with a Genesis 2 and SegaCD2...

1.7 How long was it under production for?

About half a year.  Mine says June 1994.  Production was halted when the 32X
was released in late 1994.  I suspect Sega never meant it as a mainstream
product anyway, more of a novelty.
It was relased when the SegaCD was dying too, so it would have been illogical
for Sega to continue production into the 32X and Saturn era.

1.8 Are there any compatibility problems?

One or two.
Every single Genesis game I've ever tried has worked 100% fine.  Even Virtua
Racing.  I've not heard of a game not working on this unit.
The SegaCD portion however is a tad more fussy.  It is believed that the
following games do not work -

Radical Rex
Who Shot Johnny Rock?

Jurassic Park is said to take a long time to load, but does actually work.
Some people have reported issues with Lunar Silver Star... hanging on menu's
and the like.  For ever person who claims it does not work tho, about 5 claim
it does.  I'm pretty sure it works fine.
It's worth remembering people say the same about the SegaCD2, so it might be an
issue inherited from that.

1.9 What CD Player functions are there?

It's all standard affair really.  Play/Pause, Stop, Track Forward/FForward,
Track Backwards/Rewind.  There's also a small LCD screen with the track number,
along with the volume control.
What else do you need?  No you need all this fancy bass boost stuff?  No.

Import Questions

2.1 Is the CDX region protected?

It has the same protection as the Genesis and SegaCD.
This includes chiplocking on later games, Herz-rate protection, Langauge
protection, region checking on SegaCD games etc.

2.2 How do I play import Genesis games?

Depends what you need to run.
Both the American and European versions of the unit can run non-chiplocked
games from both regions.  I run most of my European games on my American CDX
perfectly fine.  The cartridge slot size is big enough for both American and
European types of cartridge shape.
You cannot, however, use Japanese games out of the box. Both chiplocked and
normal. They are curved on each side and are too big to fit into the slot.

You can play Japanese games by what's called a pass-through cart.  These were
an early way of using import games on original Genesis machines by basically
extending the cartridge port... much like on a Game Genie.  It was designed for
people who did not want to cut that cart port to be wider to make the carts
Sega soon got wise to this however and implemented chiplocking.  It is for this
reason that I do not recommend this unless you want to run a specific game that
you know is not chiplocked... later games will not work on a passthrough.

Another more common method is the usage of an Action Replay or Game Genie.  On
these, you could enter a code to skip past the chiplocking protection.  It was
a little fiddly having to enter a code, but it worked a charm.  And these carts
are quite common.
Japanese games work fine too, chiplocked or not.

There are also carts on there which have switches on them.  Ususlly one for
region, and one for Herz rate.  These make the game think they are running on a
machine of a certain region or refresh rate, and act accordinly.  These are
very clever, and easier to use than a Game Genie or Action Replay, but also
quite rare.

Overall, considering the rarity of a switch cart, and Game Genie or Action
Replay seems the easiest option, although those who have a large collection of
early Japanese games can't really go wrong with a cheap pass-through.

It's worth mentioning that Sonic 3, although chiplocked, works 100% fine when
linked onto Sonic & knuckles (which is not chiplocked).
Also, I'm pretty sure all EA games are region-free.

2.3 How do I play import SegaCD games?

The only legit way I know of is using a product called the  CDX (yea, it's got
the same name...).  There were many different models of these released, all
seemingly being compatibile with different games.  I've never used one of
these, but I gather you will need a few different ones to get full (or near
enough) compatibility.  It pluged into the Genesis cart port and, from what I
can gather, bi-passed the SegaCd bios in order to achieve it's region-free

Another more dodgy method is to make an ISO image of your game and patch it
with a program called SCDConv, and then burn the patched image. Look on Google
for this, it's easy to find.
The SegaCD didn't have copy protection (with CD writers being dream beasts at
the time), only region protection, so once you have patched the image and burnt
it back onto disc, it should boot fine with no modifcation. There is not 100%
compatibilty, but most games work fine.
The only issue here being some audio syncronisation problems where a game is
designed to run at a specific Herz rate.  There is no way around this.

2.4 Does it play chiplocked games?

As said earlier in the FAQ, it's still region dependant.

2.5 Can the protection be bi-passed through hardware?

In theory, yes.  I've not read a  FAQ of someone bringing up the guts to open
up their CDX tho... and would you wanna hardware mod your baby anyway?  Course

2.6 I have an import machine, do I need a stepdown?

Actually, you can just pick up a MegaDrive 2 power adaptor and use it on an
American CDX fine.  I'd persume it's the same vice versa.
You can use a stepdown if you reeeeeally want to use the plug that came with it
tho... but what's the point?  A Genesis 2 is probably cheaper these days.

Utility Questions

3.1 Does the 32X work with the unit?

Contrary to popular belief, it does acually work.  It's very fiddly tho, I
don't think the clips all work, and it needs to be removed when you want to
insert a CD, but it does actually work, if rather flimsly.
The consfusion comes because the 32X manual claims it does not work at all, but
it's merely unsupported.

3.2 If so, does it play 32XCD games?

I'd presume so.  I've never tried, but I see no reason why not.
All 32XCD games are avaliable on the standard SegaCD anyway, in cut down form.

3.3 Do the Master System converters work with the unit?

The second generation model does apparently work.  By second generation, I mean
the one thta was more like a pass-through cart designed for the Genesis 2, as
opposed to the massive thing designed for the Genesis 1, which I suspect would
not fit.
This is actually really cool, the second generation cart is about the size of
Sonic & Knuckles, so it's small, and means your CDX is compatible with yet
another console!

3.4 Does the Action Replay/Game Genie work?

Yes the do, dispite popular belief.
The CDX seems to be similar to the Genesis 2 in archetecture, so you can
presume whatever works on that will work on the CDX.

3.5 Are there any incompatible utilities at all?

Apparently the EA 4-way multi-tap does not work due to the spacing of the
controller ports - It relies on them being nect to eachother.
You can get around this by using 2 controller extention cables.
I an unaware or any other compatibility issues.

4. Thanks and Contacts

First off, I'd like to thank Barry W. Cantin again for his SegaCD FAQ, without
which this would probably not have been possible.

On top of this, credit to the SegaXtreme and GameFAQ's SegaCD forums for little
tid-bits of information I learnt.

Hi to lily (love ya!), Tiles44, Monaro, S Walch, Rick, Jiomand, Timberwolf
and..well.. you know who you are, I'm tired.

Big thumbs up to all people in the current Sega scene - keep the spirit alive

(C) Shakey_Jake33 2003