ok let's see whether I can answer your question correctly.
I'm sure others will correct if my answer is inaccurate.
- Is the same an extended pcengine/turbografx system ( cd and the others
thing for be duo compatible ) than a turboduo system? What of both are
better compatible?
:Basically PC Engine came out first which runs HuCard only with RF mod as video out. Later CoreGrafx was released to address the video output with composite vide as an option. Also CD-ROM2 module and suitcase interface were released to support CD-ROM titles. There are several system cards to use with this setup as later CD-ROM titles require more RAM to run - i.e 1.0, v2.1 and v3.0 which is what you need to run those SuperCD-ROM titles. PC Engine Duo was released to end the confusion and put all these into a single unit. First Duo was in black although later Duo-R and Dup-RX were released in white. TurboGrafx is US counterpart and they are incompatible with JPN unit as it uses different HuCards pin layout. However with the release of Turbo Duo they didn't bothered with CD-ROM checking so US Turbo Duo can run both US and JPN CD-ROM titles although you still need HuCard adaptor to run JPN HuCard on Turbo Duo.
-There are some hard-hacks for these systems? Where i can get it those?
:JPN consoles can be modified to run both JPN/US titles as well as S-Video mod with amp. This gives near RGB quality video signal depends on the TV you use. There are people who does this kind of mod but expect at least $100 for the mod plus S/H.
- What about protection zone of CDROM and cards? How i can use a protected
zone card or cdrom on the system?
:JPN consoles have region checking so US CD-ROM won't work without region switch installed. However US Turbo Duo can run both US/JPN CD-ROM titles without any mod. You still need HuCard adaptor to convert the pin layout though...
- Have the CDROM some thing of protection? And the cards? How fix the
console for can run at all ?
:See above
- What about the arcade card? Is valid for arcade CDs?
:Arcade card only came out in Japan so you will need either JPN console or modified US one. Also you need Arcade Duo card for Duo and Arcade Pro for the rest.
- There are backup unit of the cards? are difficult to get? Where get it
these cards?
:Tennokoebank HuCard is backup memory HuCard and many of title support this. For PC Engine/CoreGrafx there is Tennokoebank II which is adaptor that plugged in at the back of console. You can get HuCard version from eBay for around $15 pop. For Tennokoebank II it often turns up on eBay UK.
- What problems could have a Turboduo system (compatibility and others) are
fixable these problems? How fix it?
:Given their age weak laser signal would be the major problem. Other than that JPN consoles are sturdy machine. Having no US console cannot comment on their durability.
- I can have a RGB output (scart)? is possible? how add it ?
:Yes you can. In fact I have Tennokoebank II module modified with RGB output. This is hard to come by and not so easy to do unless you are familiar with that kind of stuff...
- Where i can buy it a pcengine/turbografx/turboduo system and accessories
(including arcade card)? What of these are more cheaper ?
:eBay.
Seriously... I do have PC Engine Duo as well as suitcase setup for sale
here.
- What level of compatibility have supergrafx with the other systems ?
:It's right at the top of PC Engine family tree. It runs every thing others can run plus 6-7 SuperGrafx HuCards JPN titles.
- Is true that is possible use modified nes roms onto
pcengine/turbogfx/turboduo systems?
:Heard there was iso with these so you can burn into CD-R (PC Engine never had CD-ROM disc checking) and run from there... that's all I know really...
- Is possible use the roms on a cdrom and be run on cdrom
system/turboduo ?
:don't know. never tried nor need...