Dreamcast GDEMU

moonlighting

was the case closed while you had it on for a few hours. the fan design on it seems like poor design/placement. but nay-be the lid needs to be closed for proper air circulation.

Steve X2

moonlighting wrote: »

was the case closed while you had it on for a few hours. the fan design on it seems like poor design/placement. but nay-be the lid needs to be closed for proper air circulation.

Yeah the case was on and the lid closed. Might just swap over to another DC and see how it goes.

KeRbDoG

My 2cents for what its worth - Dreamcast PSUs run hot from my experience. That fan, while tiny, creates a suction to pull air across the heat pipe setup and also to pull air across the PSU albeit not with a lot of force
The GD-ROM most likely acted like a filler in the top of the case of the Dreamcast, without it being plugged, the air is now most likely getting pulled in through the drive lid and not pulling it across the PSU as effectively as it used to

Steve X2

KeRbDoG wrote: »

My 2cents for what its worth - Dreamcast PSUs run hot from my experience. That fan, while tiny, creates a suction to pull air across the heat pipe setup and also to pull air across the PSU albeit not with a lot of force
The GD-ROM most likely acted like a filler in the top of the case of the Dreamcast, without it being plugged, the air is now most likely getting pulled in through the drive lid and not pulling it across the PSU as effectively as it used to

I was thinking something along the same lines as this after some testing last night.
I'll test it out in a completely different DC and see if it's the same. If it is then maybe I'll need to 3D print up some sort of filler block, which will be a pain.

Myrddin

With all that extra room in the DC with the GD-rom unit removed, it'd be handy enough to add in another small/quiet fan & design a basic air-channel in there

o1s1n

Myrddin wrote: »

With all that extra room in the DC with the GD-rom unit removed, it'd be handy enough to add in another small/quiet fan & design a basic air-channel in there

That'd be a great solution alright.

It seems like the kind of thing that would have been caught at the testing phase, I wonder is it just happening with this one particular Dreamcast?

Quite the oversight if it's going to happen as standard.

KeRbDoG

Would be good to hear the reports of others - after reading more about the GDEMU, suddenly I want one. Would give me extra room for that internal VGA mod someone on here gave me the parts for year ago (can't remember who, but many thanks for doing it!)...luckily they can't be pre-ordered currently so my bank account is safe, for now

Steve X2

Another DC and 1 hour into a test with Crazy Taxi and the temps are looking pretty high

Steve X2

This is after about 2 hours running Crazy Taxi on a different DC(case was on and lid closed)



I'll do some testing later on with the same DC but with the GD-Rom drive in and a retail disc of Crazy Taxi and see how she goes.

o1s1n

I wonder, does the the GD Rom drive itself kind of act like a fan when the disc is spinning?

Enternow's Myrddin's (I'll still keep bloody typing Enternow!) fan idea was interesting if it would fit.

Otherwise maybe some sort of case mod to allow more ventilation?

Steve X2

o1s1n wrote: »

I wonder, does the the GD Rom drive itself kind of act like a fan when the disc is spinning?

Enternow's Myrddin's (I'll still keep bloody typing Enternow!) fan idea was interesting if it would fit.

Otherwise maybe some sort of case mod to allow more ventilation?

I wonder would some heat sinks help at all. Silent and easy to stick anywhere as you can get them big and small.

Surprised the guy didn't come across the issue when developing it. Or maybe it's just two bad DC's?? Unlikely but possible.

Steve X2

So I plugged the GD-ROM drive back in and let Crazy Taxi play away for a couple of hours.
Seems to be a lot better.

Steve X2

I've been looking online but the only half decent 3D model of the dreamcast I can find is 60 dollars to download. And that doesn't even include the internals modelled, so I'd have to design my own.

If anyone by chance has a decent model of the DC, i can do something up in Solidworks and thermal test it and see what the best solution is to this heat issue. I did it with the Game Boy a couple years ago when I was building a PC into one.

This sort of thing:

https://www.youtube.com/watch?v=UxqiGGsPOlU

Myrddin

Nice discovery Steve, temps basically doubling with the GDEmu installed :eek: I'd try avoid case modding unless absolutely necessary, & look at at getting a small fan or two in there...even little ram coolers, they're small enough to fit in.

TotallyEpic

What about just running it without the cover? Not ideal, but might be better..

Steve X2

Myrddin wrote: »

Nice discovery Steve, temps basically doubling with the GDEmu installed :eek: I'd try avoid case modding unless absolutely necessary, & look at at getting a small fan or two in there...even little ram coolers, they're small enough to fit in.

Yeah, small heatsinks may be the way to go I think. I got some nice copper ones for the raspberry pi a while back and you just stick them on.

TotallyEpic wrote: »

What about just running it without the cover? Not ideal, but might be better..

My plan for one of the DC's is to go inside my arcade machine so it wouldn't be the end of the world if the top case was off.

My plan is to wire up control buttons to the GDEMU and extend the DC power button to some small home made control panel I can put inside the main arcade cpanel. That way I can both power on/off the DC from the cpanel as well as select the next/previous game on the GDEMU.

After a little testing last night its fairly clear that the fan is completely useless with the case off and does more or less nothing. So I don't need it for the DC that's going in the arcade machine.
But, the DC has a kill switch built in, if it detects the fan is unplugged or not running it simple wont power up the DC or will in fact power it down. Any way around this folks? Wire up something else that needs 5v like an LED or something? But I'm guessing the DC reads the fan speed so not sure how to get around that.


Edit:
Testing out a nude DC. Plan might be to mount it on a small bit of MDF and use Sugru to hold a few things in place on the console itself.

fluxcore

Interesting stuff. I just installed my GDemu, but haven't had a chance to put it through its paces, so this is certainly something I'll be looking out for fixes for

I guess cooling the PSU is one thing, but I presume the other big heat generator would be the Holly chip (GPU) - surely passive cooling wouldn't be sufficient for that? I know for sure that in the Atomiswave system, that chip gets VERY hot.

Have you tried contacting Deunan directly to see what he has to say about it?

KeRbDoG

I would leave the fan mounted so it will be pulling air across the side of the metal case which the heat pipe terminates. While your taking temps of the PSU, your not taking temps of the CPU/GPUs so yea could be cooking them without that fan.
Leave the stock fan and connect a low RPM fan to one of the power output headers and have it pull air across the PSU, should be able to get a fan that would stick within the case or if your gonna have your DC going nude, a good old 10-12cm fan would work great.

Relikk

There's another weird problem that's been discovered over the past week. I gave my two DC's to Myrddin to mod with region free BIOS last week and stuck a Japanese copy of Super Street Fighter II X on the GDEMU SD card for him to test when they were done. He noticed that the resolution had been bumped up and only the top left quadrant is displayed on the whole screen.

Apologies for the quality, the lighting in the room is bad.



It's like it's detecting VGA and bumping up the resolution. I did pop the GD-ROM drive back in and I tested my legit JAP copy of SFIII 3rd Strike, it worked perfectly. Then the GDEMU went back in and I tested a GDI dump of the same game and that worked perfectly just as the disc copy did before it. Unfortunately I don't have an original disc copy of SSFIIX to test.

I'm currently pointing it out to Bad_Ad84, who I got the BIOS chips from but, he's never come across this before.

Myrddin

Relikk wrote: »

It's like it's detecting VGA and bumping up the resolution. I did pop the GD-ROM drive back in and I tested my legit JAP copy of SFIII 3rd Strike, it worked perfectly. Then the GDEMU went back in and I tested a GDI dump of the same game and that worked perfectly just as the disc copy did before it. Unfortunately I don't have an original disc copy of SSFIIX to test.

I'm currently pointing it out to Bad_Ad84, who I got the BIOS chips from but, he's never come across this before.

Best I can figure is that game image might have been manually VGA patched or something? Every other image I tested the GDEMU with worked perfectly

Relikk

Myrddin wrote: »

Best I can figure is that game image might have been manually VGA patched or something? Every other image I tested the GDEMU with worked perfectly

Same thing happened with the JAP version of Darkstalkers. I'm going to test Ikaruga in a sec.

o1s1n

Relikk wrote: »

Relikk wrote: »

:

Jaysus for a moment there I thought that was my old sitting room!!! :eek:

(I really do miss that TV )

[IMG][/img]

o1s1n

So in summary it would seem it's best to stay away from GDEMU for now?

Relikk

o1s1n wrote: »

Jaysus for a moment there I thought that was my old sitting room!!!

That AES would have felt right at home.

Hard to say, really, without legit copies of the games in question. It could be the BIOS, it could be the GDEMU.

Steve X2

I was on to the guy who developed the GDEMU and asked him to have a look at this thread.
For the temperature issue he reckons building some cardboard tunnel to funnel the air out. And said 70c isn't that hot.
I don't agree with the cardboard or the temp comment. Something other than cardboard is required for this job me thinks and 70c is pretty darn hot for a PSU of any sort.

Myrddin

Relikk wrote: »

Same thing happened with the JAP version of Darkstalkers. I'm going to test Ikaruga in a sec.

Can you burn the affected image & run it in a stock DC via Utopia?

Relikk

Myrddin wrote: »

Can you burn the affected image & run it in a stock DC via Utopia?

It wouldn't be the original GDI then, I suppose. I do have an old self bootable .cdi copy burned years ago and that always worked fine but again, it's not a copy of the original disc. A clean dump is needed. Someone submitted one to TOSEC a couple of years ago but, it still doesn't appear in their sets but, then again I got the Darkstalkers GDI from the TOSEC set and that was the same.

Steve X2

Too Hot for My Chinchilla

http://gdemu.wordpress.com/2014/05/26/too-hot-for-my-chinchilla/

o1s1n

Steve SI wrote: »

Too Hot for My Chinchilla

http://gdemu.wordpress.com/2014/05/26/too-hot-for-my-chinchilla/

Fair play to him for commenting on this but the answer is too wishy washy and a bit worrying.

'I don't think its a problem' and 'I didn't test..' aren't exactly two phrases that fill me with confidence.

Hopefully it doesn't result in a spate of failed PSUs.

Myrddin

Relikk wrote: »

It wouldn't be the original GDI then, I suppose. I do have an old self bootable .cdi copy burned years ago and that always worked fine but again, it's not a copy of the original disc. A clean dump is needed. Someone submitted one to TOSEC a couple of years ago but, it still doesn't appear in their sets but, then again I got the Darkstalkers GDI from the TOSEC set and that was the same.

Yeah true I suppose. From the GDEMU site linked to above:

GDEMU does not remove region lockout. In other words, your Dreamcast will refuse to boot games from other regions just as it would refuse original GD-ROMs. This is on purpose, because…

Even patched to allow all region booting, some games will not work. This has nothing to do with GDEMU, it’s in the game code. Most games can be easily patched but some require a specific video output to be present – for example, USA region game might not work with RGB cable which is pretty much the default in EU. And there are a few titles that will just not work in non-native region, period.

In general it’s strongly recommended you stick to games for your region, and if you want to experiment then at least check how the original behave before you blame GDEMU.

This doesn't reference the region free bios, but more so manual image patching...though I wonder if it's still applicable? Maybe try a PAL image of the game where the graphics are messed up?

Steve X2

o1s1n wrote: »

Fair play to him for commenting on this but the answer is too wishy washy and a bit worrying.

'I don't think its a problem' and 'I didn't test..' aren't exactly two phrases that fill me with confidence.

Hopefully it doesn't result in a spate of failed PSUs.

He still reckons 70c is not problem for the psu :eek:
At 70c you can smell the electronics heating up and the plastic is very hot indeed so your white DC will become yellow a lot sooner.

Relikk

Myrddin wrote: »

This doesn't reference the region free bios, but more so manual image patching...though I wonder if it's still applicable? Maybe try a PAL image of the game where the graphics are messed up?

They were never released for the PAL region, unfortunately.

Myrddin

Relikk wrote: »

They were never released for the PAL region, unfortunately.

I know it wouldn't be a true test, but if you burned a cdi image of SSF2X & tried it in a stock DC, & that same thing happened, it'd at least help rule out the GDEMU as being the cause of it. It it did still happen, it'd help rule out the bios chip causing it...

Relikk

Myrddin wrote: »

I know it wouldn't be a true test, but if you burned a cdi image of SSF2X & tried it in a stock DC, & that same thing happened, it'd at least help rule out the GDEMU as being the cause of it. It it did still happen, it'd help rule out the bios chip causing it...

I actually completely forgot that CDI images are supported on the GDEMU so, I can try one instead of burning one. Just prefer unaltered GDIs considering the amount of messing around to get them to fit onto CDRs in the first place, compressing audio etc.

I'll try a CDI of SSFIIX when I get home.

Steve X2

Relikk wrote: »

I actually completely forgot that CDI images are supported on the GDEMU so, I can try one instead of burning one. Just prefer unaltered GDIs considering the amount of messing around to get them to fit onto CDRs in the first place, compressing audio etc.

I'll try a CDI of SSFIIX when I get home.

If you get a chance can you load up crazy taxi and leave it run for an hour or two and see if the PSU gets hot?

Relikk

Steve SI wrote: »

If you get a chance can you load up crazy taxi and leave it run for an hour or two and see if the PSU gets hot?

I've no way to measure the temps but, yeah I'll leave it on for a while.

Relikk

Left it on for a little over 2 hours last night with Crazy Taxi, case on and lid closed. Touching the case, it was warm, nothing I would deem out of the ordinary. Couldn't smell anything.

Using the ReviveDC CDIs, the two Capcom fighters worked perfectly, and played at 60hz, including Ikaruga. When I tried the GDI of Ikaruga it played at 50hz.

Steve X2

I see the guy who made it has been doing some temp tests himself.

http://gdemu.wordpress.com/2014/06/01/mr-driller/

I’ve run some tests to measure the PSU temperature in several different scenarios, both with original GD-ROM drive and GDEMU installed. The most interesting case was one with GD-ROM drive but no disc, and cover completly removed:




Without any forced airflow the convection alone is not able to cool the radiators below some 70°C. It doesn’t get any worse than this though, basically the PSU reaches thermal balance at this point and stays that way.

With the cover installed PSU will heat up to about 58°C. Running the console without cover and then reinstalling it after some time will cause the temperature to drop eventually. In other words, the airflow inside the case does make some difference.

I’m a big fan of simple solutions so this is what I did:



I’ve also complety taped off the air inlet at the back of the console, so now most of the airflow will go through these holes and cool PSU down. With GDEMU installed it reached 63°C after an hour. It’s just 5 degrees more than with the original drive so I think I’m done making holes

One other point of interest, PSU voltages:

GD-ROM drive (no disc): 3.296V / 5.030V / 13.28V
GDEMU: 3.305V / 5.042V / 14.26V
Even without a disc inserted the original drive pulls some current from 12V line. GDEMU doesn’t (and uses much less power in general) so it’s possible the PSU is running in a bit less efficient way now.

Keep in mind this a 230V PSU, the 110V one might behave differently. I’m going to test that as well in a day or two. Still, the capacitors in the PSU are 105°C rated so 70 rather than 58 degrees is not going to suddenly damage them. If this thing was properly designed it should handle even less favourable conditions than that. After all SEGA guys did put the fan on the opposite side so overheating the PSU was not a major concern for them.

moonlighting

I managed to get mine working with a lcd screen menu. its a small 16 x 2 lcd hooked up to an Arduino. so when i am updating the sd card i hook the Arduino up to the computer aswell via usb and write in the games list. When the dream cast powers on i can cycle threw the games list via a up and down button and on the lcd screen it shows the current game selected and on the next line the next game etc.
if you guys are interested in building a similar setup i could clean up the Arduino code and make a schematic and parts list.

fluxcore

Well, post some pics and stuff, it certainly sounds interesting enough to write up!

moonlighting

ill post up a youtube vid tomorrow sometime.

moonlighting

http://ogprojects.wordpress.com/2014/06/06/dreamcast-mod/

80s Synth Pop

many thanks for this. I'll give it a try

Myrddin

Old thread I know, but getting back to the heat issue there's a solution on Assembler - http://assemblergames.com/l/threads/replacing-the-dc-psu.53856/