tvset
What's a PC Engine?
Posts: 2
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Post by tvset on May 10, 2020 7:09:55 GMT
Hello everyone, when NEC announce the release of Arcade card, rumor has it that the arcade card may contains a 32-bit co-processor to enhance the pc-engine power. We all know that it is not true, but I always have this question in my mind: Is it really possible to enhance the PC-engine that way? Is it technically viable? I know that it is meaningless now, but as a royal pc-engine fan back in the days, I really like to see some real enhancement to the pc-engine like realtime scaling and rotation effects, multi-plane scrolling, etc...
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Post by spenoza on May 10, 2020 13:50:41 GMT
I don’t think the PC Engine has the proper bus lines on the cartridge port to do that. Now, it could do graphical enhancements out the expansion bus no problem, but the PC Engine would be handing over part of an image for what is effectively a new CPU/GPU combo to build on, most likely. It would look a lot like what the Sega CD or 32x did.
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nicole
Gun-headed
Posts: 50
Fave PCE Shooter: Magical Chase
Fave PCE Platformer: Legendary Axe II
Fave PCE RPG: Ys III
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Post by nicole on May 10, 2020 14:52:16 GMT
I don’t think the PC Engine has the proper bus lines on the cartridge port to do that. Now, it could do graphical enhancements out the expansion bus no problem, but the PC Engine would be handing over part of an image for what is effectively a new CPU/GPU combo to build on, most likely. It would look a lot like what the Sega CD or 32x did. Looking at the pinout I don't see why you couldn't do something like the SuperFX, which as far as I can tell renders to a frame buffer in in-cartridge RAM that the code running on the main CPU copies to video memory. That's still pretty limited compared to something like the 32X, but it could still do some neat effects.
I bet the size and thermal constraints of a HuCard would be pretty limiting, though.
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Post by SignOfZeta on May 10, 2020 15:52:55 GMT
I’d be more worried about power consumption. Some PCEs can’t even use certain flash cards because of the limited current at the cart slot. A modern chip sure but something back in the day may have needed its own power supply like the 32X and IMO once you start seeing parallels to the 32X it’s time to stop.
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Post by Black_Tiger on May 10, 2020 16:01:47 GMT
I believe that the last time PCE tech experts weighed in on this the one thing they said was very doable was extra audio through the HuCard slot.
It was pitched during polling/discussions on what to add to a bew HuCard design for homebrew.
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Post by dshadoff on May 10, 2020 19:41:10 GMT
Sound is possible, but since there is only one channel going back in through the cartridge port, I doubt that this would be too satisfying.
All sorts of other things could be possible, depending on what you're willing to accept for external connections:
1) bluetooth or other non-standard controller interfacing 2) a second video output with a brand new video processor (assuming that connections from the card to an output don't put too much physical force on the connections) 3) additional storage of huge capacity 4) coprocessor to uncompress and/or decrypt arbitrary data faster than the CPU 5) 3-d type render engine which generates a raster scan which the PC Engine simply 'blits' back to the screen.
... the possibilities are endless, but at a certain point, the PC Engine is no longer a PC Engine, and becomes a mere slave processor.
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Post by turboxray on May 11, 2020 5:20:23 GMT
You could get some nice graphic effects. Similar to how the SegaCD ASIC or the SNES SuperFX, etc. A chip that could do some multi-layer compositing and bit shifting for dynamic tiles would be prime for the PCE.
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gilbot
Punkic Cyborg
Posts: 137
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Post by gilbot on May 11, 2020 9:45:57 GMT
This may be an interesting concept considering how frequently this was done in Nintendo's systems(I mainly meant Famicom and Super Famicom, especially the latter), and Virtua Racing on Mega Drive (I'll just ignore the Mega CD and 32X for now as you may consider them separate consoles), but I'm actually more interested on what the system can do without. For example, "3D" stuff with flat shading polygons or wireframe graphics (there are a few games with polygon rendering on the Mega Drive without extra hardware and for Famicom, we at least have the wireframe Elite). I can only name a few, most of which not very impressive:
1. Opening of HuCard Space Invader (impressive, but well, wireframe is just wireframe) 2. FaceBall 2000 (I think it's using raycasting or whatever, but while it's impressive performance is not good when there are more than two simultaneous players on screen) 3. GunBoat (We know this is NOT impressive, no wonder it was never released in Japan) 4. Errr... I think there may be a flight simulator only released in the west (which is as good as GunBoat) or I'm just making this up 5. Errr... I think I cannot recall more of this (Games with pre-rendered stuff such as Sapphire or the cutscenes in Strider obviously don't count.) I'm not sure whether people didn't even try or the system really sucks there.
Another example are isometric games (though these doesn't matter much whether there is a co-proprocessor). There are only VERY few such games (all that I can recall are Populous and Götzendiener and the latter isn't even good in any aspect...).
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Post by spenoza on May 11, 2020 13:10:29 GMT
We have to remember that the NES and SNES exposes more system access on their cartridge lines than other systems of the day.
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Post by Black_Tiger on May 11, 2020 14:16:09 GMT
This may be an interesting concept considering how frequently this was done in Nintendo's systems(I mainly meant Famicom and Super Famicom, especially the latter), and Virtua Racing on Mega Drive (I'll just ignore the Mega CD and 32X for now as you may consider them separate consoles), but I'm actually more interested on what the system can do without. For example, "3D" stuff with flat shading polygons or wireframe graphics (there are a few games with polygon rendering on the Mega Drive without extra hardware and for Famicom, we at least have the wireframe Elite). I can only name a few, most of which not very impressive: 1. Opening of HuCard Space Invader (impressive, but well, wireframe is just wireframe) 2. FaceBall 2000 (I think it's using raycasting or whatever, but while it's impressive performance is not good when there are more than two simultaneous players on screen) 3. GunBoat (We know this is NOT impressive, no wonder it was never released in Japan) 4. Errr... I think there may be a flight simulator only released in the west (which is as good as GunBoat) or I'm just making this up 5. Errr... I think I cannot recall more of this (Games with pre-rendered stuff such as Sapphire or the cutscenes in Strider obviously don't count.) I'm not sure whether people didn't even try or the system really sucks there. Another example are isometric games (though these doesn't matter much whether there is a co-proprocessor). There are only VERY few such games (all that I can recall are Populous and Götzendiener and the latter isn't even good in any aspect...). Tom recently said in another forum that a lot of scaling effects like Afterburner II's ship and plane as well as most mosaic effects are realtime/"brute force".
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nicole
Gun-headed
Posts: 50
Fave PCE Shooter: Magical Chase
Fave PCE Platformer: Legendary Axe II
Fave PCE RPG: Ys III
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Post by nicole on May 11, 2020 17:35:35 GMT
We have to remember that the NES and SNES exposes more system access on their cartridge lines than other systems of the day. I'm looking at the pinout of the SNES; which necessary lines are there that are missing on the HuCard slot?
Of course the NES is very different due to the PPU bus being exposed.
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Post by turboxray on May 12, 2020 3:13:24 GMT
This may be an interesting concept considering how frequently this was done in Nintendo's systems(I mainly meant Famicom and Super Famicom, especially the latter), and Virtua Racing on Mega Drive (I'll just ignore the Mega CD and 32X for now as you may consider them separate consoles), but I'm actually more interested on what the system can do without. For example, "3D" stuff with flat shading polygons or wireframe graphics (there are a few games with polygon rendering on the Mega Drive without extra hardware and for Famicom, we at least have the wireframe Elite). I can only name a few, most of which not very impressive: 1. Opening of HuCard Space Invader (impressive, but well, wireframe is just wireframe) 2. FaceBall 2000 (I think it's using raycasting or whatever, but while it's impressive performance is not good when there are more than two simultaneous players on screen) 3. GunBoat (We know this is NOT impressive, no wonder it was never released in Japan) 4. Errr... I think there may be a flight simulator only released in the west (which is as good as GunBoat) or I'm just making this up 5. Errr... I think I cannot recall more of this (Games with pre-rendered stuff such as Sapphire or the cutscenes in Strider obviously don't count.) I'm not sure whether people didn't even try or the system really sucks there. Another example are isometric games (though these doesn't matter much whether there is a co-proprocessor). There are only VERY few such games (all that I can recall are Populous and Götzendiener and the latter isn't even good in any aspect...). The main thing that limits the PCE, is the planar graphics. It's just not meant for pixel based stuffs. But.. there are some other advantages. The PCE's cpu is pretty fast and can handle the 3D transitions, but the pixel fill is going to be slow because of the tile composite-planar format. While the PCE can update vram at any time including active display, it's not quite as fast as the Genesis or SNES, so it trades some cpu performance for it. If the PCE had a bitmap mode, or linear pixel tiles like the Genesis, it would be a lot faster at pixel base stuff. The SNES wolf3D demo is pure snes, but it uses linear pixel mode of mode7, and gets free scaling to make it full-ish screen (120x80 res upscaled to full screen). The PCE *can* do something similar to that, and highres, but is limited to about 16~20 colors (the SGX could do 240 colors) with a pseudo bitmap mode (you render directly to vram). The same setup could do something similar to Sonic mode7 "mario kart" demo or the Fzero demo (https://www.youtube.com/watch?v=hMz1T0uTzLI) on the Genesis, on the PCE. I ran the numbers.. probably not as high frame rate but in the 18~20fps range. Basically the PCE can do a pseudo bitmap mode (128x128 pixels auto-scaled to 256x128 or 256x240) for fast rendering, but no game uses it AFAIK. Wire frame graphics could be pretty fast on the PCE, because you could just write to a single bit plane.. but it's not that exciting haha. Since PCE's tiles are composite planar graphics, you could do "transparent" dynamic tiles. I have a TF4 ocean side demo on the PCE that has transparent clouds scrolling against the mountain back drop. But yeah, there are a few tricks it can do that haven't been done with commercial games (or even demos).
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gilbot
Punkic Cyborg
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Post by gilbot on May 12, 2020 5:23:07 GMT
Since PCE's tiles are composite planar graphics, you could do "transparent" dynamic tiles. I have a TF4 ocean side demo on the PCE that has transparent clouds scrolling against the mountain back drop. Using plannar graphics also means it is relatively easy to have effects such as smoothly (well, as smooth as it can be with a 9-bit master palette) transition from one 4 colour (2 bit/2 planes) image to another. I remember one cutscene early in Kabuki Den showing the evil overlord being ressurected (or whatever, it's long time ago) and I thought they're using this trick (maybe not as I never analysed it). Still, even as proof of concept, I still want to see more polygon stuff (or other 3-D tricks such as raycasting) done, to at least showcase how well(or bad) the system can be in this department. For wireframe graphics I think some homebrewer may at least try porting Elite to it, seeing how well it ran on the Famicom, the PCE should be able to handle it even better.
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samiam
Punkic Cyborg
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Post by samiam on May 12, 2020 5:25:56 GMT
I’d be more worried about power consumption. Some PCEs can’t even use certain flash cards because of the limited current at the cart slot. A modern chip sure but something back in the day may have needed its own power supply like the 32X and IMO once you start seeing parallels to the 32X it’s time to stop. Per this guy, the SFX chip appears to consume nearly 100mA, while the DSP in Super Mario Kart is closer to 10mA. Per this, the SVP Chip in Virtua Racing apparently runs on 40mA. The PCE can supply current up to the point that the 7805 regulator overheats goes into thermal shutdown mode. For any given amount of current it's supplying, there will be two factors involved in how hot the 7805 gets: the voltage at the input, and the efficiency of the attached heat sink. What makes things a bit more complicated than with the SNES is how many different versions of PCE hardware there are: each external power supply might deliver a different voltage (none of them are regulated), and each heat sink might have a different efficiency. Not to mention, anyone using a Japanese power supply in a North American outlet is boosting their input voltage another 20%. I could see 100mA being a risk in some cases. I really don't know, though.
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Post by dshadoff on May 12, 2020 5:54:41 GMT
...Especially when people are running the SSDS3 or UperGrafx or CDROM attachment (and/or whatever other modifications are in the machine) from the stock PSU...
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