Can it be done? Something like a dock connector to connect the portable system to a CD system and play CD games on the 3" screen? There are small connectors like SCSI 68 pins that could fit inside and if you sacrifice a dead PCE or TG-16 for the standard connector, one could probably build a cable to connect the handheld system to CD system. I don't have a schematic handy but I would assume all of the parts in handheld is the same as the console minus the ext connector. Not looking for portable CD gaming, I doubt the 25 year old CD system has good anti-skip technology to begin with.
If all of the signals and corresponding chips are there, then yes. If you can add the Expansion Port, then Composite Video, stereo audio, and RGBS outputs can be used with the Turbo Express/PC Engine GT. I found a pinout of the Expansion Port if you need it: http://www.gamesx.com/misctech/pcebp.php I noticed that H-Sync and V-Sync are present there. This leads me to believe that RGBHV CGA (15KHz equivalent of RGBHV VGA) output is possible. This will give better quality than the RGBS used in RGB SCART/JP-21 cables. I'll post a thread for that in the modding section shortly.
Not likely possible, the BIOS on the TE/PCE GT was not designed to recognize an external component such as the CD unit. There's more to it than matching up video pin outs and system functions.
The BIOS is unique to the hardware that it’s been designed for. A system Hucard would not work, as the firmware is designed for use on a console …. not a handheld.
It has bios? I thought PCE, TG-16, etc all don't have any kind of ROM chip inside, just CPU, video, audio, and some RAM. Nothing like a BIOS.
The PC-Engine doesn't have a "firmware" or a "BIOS". The System Card HuCard contains the BIOS for loading and running CD programs. In Super CD-ROM systems (including the DUO) the System Card is built in. You could potentially connect the CD System to the portable system assuming all the required signals to make it work are present. If you can find them all then there is nothing stopping someone from wiring it up. It wouldn't be at all practical but you could probably use it though not while moving as noted that CD skipping could be an issue. Perhaps a more likely test subject than a portable unit would be the PCE Shuttle unit which has a slightly condensed expansion connector. It has all the required signals present for the CD apparently except for IRQ2. If you could find that signal then presumably it would work.
This makes me wonder if the Sega Nomad could work with the Sega CD/Mega CD if one was to add the connector.
I'm not familiar with the Sega CD hookup but again the idea is the same. Assuming all signals are present, something could potentially be hacked together. The Genesis Model 3 is missing some signals to the cartridge port as I recall which impacts 32X and Powerbase Converter usage but it's possible to find these signals and restore this functionality. I don't have a link but I'm pretty sure it's been done. But I don't think anyone has tried to hookup either PCE CD or Sega CD to a portable system. Probably because it wouldn't be a very useful mod at all. Atleast something like the Genesis 3 mods I mentioned actually have reasonable use.
Shuttle isn't portable and no built in LCD. What I was thinking was to carry around TE for playing card games, and 'docking' for playing CD game. It does seems possible. All I need is a TE or a GT, a connector (out of a dead system) to go into the CD system plus a mini connector of some type for quick connecting for docking. Looking at the pinout, I think I can skip all 8 VD's (video data) as those weren't implemented. It was suspected it would be used in future expansion like Super Grafx upgrade module or something bigger like 32X type upgrade. First stop: find a decent schematic so I could figure out where all the important pins are and then figure how to route them to bring out CD support.
You may just need to get a home system and try to trace from the connector to where it originates inside the system. Then see how that applies to the portable unit. Seems silly though if you aren't going to play the CD system on the go, why not just use a home system? Why go to the trouble to modify an expensive portable system?
Because I can? People have hacked Neo Geo systems and those costs a lot more than a working TE and GT.
People have put entire Game Boy systems into an NES cart and got it to work on the NES. I say go for it. You could even turn the whole CD Drive into a portable CD Player that attaches to the TE/PCE GT via a cable and runs off rechargeable batteries. It wouldn't be very practical but it would give you the ultimate TG-16/PCE experience on the go. While you are at it, you might want to consider wiring up your own composite video, stereo audio, and RGBS (with C-Sync; don't use Composite video for sync) cables to the EXP. port. That way it is a portable TG-16 that can be used as a true home console on a TV. If you do hook it up to the TV, remember to add a controller port and a switch to turn off the screen.
Because you can doesn't mean you should. Here is a reason why you might not want to do it. You may end up with a hacked up/broken Turbo Express as well as lose time and money on it. But if that doesn't matter and you are just looking for something to do I can see doing it. However there may be better projects to do. Although I see the appeal of the idea. You could just get the PC-Engine LT. It's supposed to be able to hookup to the CD-ROM.
LT is probably worth more than my car plus from the pictures I've seen, it may not fit my Turbo CD system because the LCD lid would be forced closed in order to fit under the CD deck.
The LT with the CD-ROM illustrates your idea and I can see the appeal more now. If you do go forward I'd just advise to do alot of planning and try to make it a very professional looking mod.
I agree with MottZilla, definitely plan it out and make it look like it came out of the factory with the port installed. I recommend using a port that is both small enough for the TE/PCE GT and has enough pins. SCSI ports are perfect as long as you use one with enough pins. Also, if you can, make the CD Drive portable so you can take it with you wherever you bring your TE/PCE GT. While you are at it, make your own custom RGBS (cable type depends on your equipment) with stereo audio and Composite Video with stereo audio cables for using it on a TV. One more thing, don't forget the regions mods. It could be really useful if you get into PCE/TG-16 importing.
