It is currently Sun Dec 10, 2017 10:43 pm

All times are UTC - 7 hours





Post new topic Reply to topic  [ 124 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9  Next
Author Message
PostPosted: Fri Nov 24, 2017 12:14 pm 
Offline
User avatar

Joined: Thu Sep 15, 2016 6:29 am
Posts: 444
Location: Denmark (PAL)
If you're targetting CRT diplays, there's no real reason to go for square pixels though...


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 12:20 pm 
Offline

Joined: Wed May 19, 2010 6:12 pm
Posts: 2420
Most game systems leave about 25% of a scanline for H-blank, so you might as well clock it at 27Mhz.

I've been researching stuff about the GBA, and is it true that the GBA can DMA up to 80kB to VRAM during V-blank?


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 12:26 pm 
Offline
User avatar

Joined: Sat Feb 12, 2005 9:43 pm
Posts: 10164
Location: Rio de Janeiro - Brazil
Sumez wrote:
If you're targetting CRT diplays, there's no real reason to go for square pixels though...

Why would anyone target CRT displays in 2017? Sure we keep them around for the old stuff, but it's only a matter of time until it becomes impossible to find a working CRT.


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 12:35 pm 
Offline

Joined: Sun Sep 19, 2004 11:12 pm
Posts: 19322
Location: NE Indiana, USA (NTSC)
Sumez wrote:
If you're targetting CRT diplays, there's no real reason to go for square pixels though...

Unlike unassisted* fourth-generation consoles, the GBA can rotate sprites. Rotation is slightly more practical with square pixels, especially for sprites such as Sonic the Hedgehog that appear unrotated most of the time and rotated occasionally. It's especially more practical in 90-degree situations.

The Super Game Boy doesn't compensate for the host PPU's 8:7 PAR, but the Game Boy Player does compensate for the 10:11 PAR that the GameCube's native 27 MHz video output would entail.


* The Super FX GSU2 in Yoshi's Island is assistance.


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 1:00 pm 
Offline

Joined: Wed May 19, 2010 6:12 pm
Posts: 2420
If you're designing a system made for an HDTV, then you can divide the 148.5 Mhz dot clock by 5, and get a dot clock of 29.7 Mhz, and take 5 scanlines to draw a row of 5x5 pixels. It could draw 1 BG layer per scanline and draw sprites on the last.

On the other hand if you're going analog route, doesn't Sega Saturn have a GBA-style VDP where it's clocked 4x the pixel rate?


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 3:42 pm 
Offline
User avatar

Joined: Thu Sep 15, 2016 6:29 am
Posts: 444
Location: Denmark (PAL)
tokumaru wrote:
Sumez wrote:
If you're targetting CRT diplays, there's no real reason to go for square pixels though...

Why would anyone target CRT displays in 2017? Sure we keep them around for the old stuff, but it's only a matter of time until it becomes impossible to find a working CRT.

I agree, my statement was based on tepples' assumption pertaining to overscan.

The rotation argument is a pretty decent rebuttal, though. Dealing with 360 degree direction vectors in an uneven coordinate system can be pretty complicated, too. I never thought about it before, but that must have been a pretty relevant issue for Cave's shooters on the PGM system. PGM has an absurdly large "horizontal" resolution.
At least the pixels are mostly 2:1, the CPS2 has a more awkward horizontal resolution, considering it's still running on 4:3 monitors:
Image


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 6:31 pm 
Offline
User avatar

Joined: Mon Sep 15, 2014 4:35 pm
Posts: 3152
Location: Nacogdoches, Texas
tokumaru wrote:
Sure we keep them around for the old stuff, but it's only a matter of time until it becomes impossible to find a working CRT.

Oh please, this stuff lasts forever. :lol:

tepples wrote:
Unlike unassisted* fourth-generation consoles, the GBA can rotate sprites.

You forget about Mode 7 though; I don't think I've ever seen a game on the SNES where a spinning background takes the 8:7 PAR into account (even if all the sprite graphics do). Most all games I've played on any 2D system don't take into account the PAR for object speed either; you'll play overhead games where ovals are shrunk/stretched to be circles, but the player will still move faster across one axis. I personally wouldn't even bother about the 8:7 PAR on the SNES if I were designing a game (not just an engine); it causes more of a headache (and even a possible performance hit; it's more difficult to do sub pixel movement) than it improves the visuals, especially considering that most people would probably play it on an emulator in 8:7 anyway.


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 8:54 pm 
Offline

Joined: Wed May 19, 2010 6:12 pm
Posts: 2420
I only really pay attention to aspect ratios, if I am using a circular object. If it's a character animation, good luck with that. I do wonder if Capcom's development set used computers with their weird PAR.


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 9:14 pm 
Offline
User avatar

Joined: Mon Sep 15, 2014 4:35 pm
Posts: 3152
Location: Nacogdoches, Texas
I heard they used Sharp X68000s through at least the CPS1's lifetime. It must have been a real pain to draw the graphics if that's actually the case.


Top
 Profile  
 
PostPosted: Fri Nov 24, 2017 9:15 pm 
Offline

Joined: Sun Sep 19, 2004 11:12 pm
Posts: 19322
Location: NE Indiana, USA (NTSC)
Sumez wrote:
The rotation argument is a pretty decent rebuttal, though. Dealing with 360 degree direction vectors in an uneven coordinate system can be pretty complicated, too. I never thought about it before, but that must have been a pretty relevant issue for Cave's shooters on the PGM system. PGM has an absurdly large "horizontal" resolution. At least the pixels are mostly 2:1

What exactly is the dot clock rate on a Cave CV1000? The MAME driver lists crystal X1 as 12.8 MHz, but the precise video timing hasn't been measured. If the 448x224-pixel video output is at this same rate, then it'd be awfully narrow through a SuperGun (JAMMA to NTSC converter). My dot clock rate list describes how each system would appear on a standard 4:3 TV through a SuperGun, though the PAR in practice may differ because of nonstandard active picture periods that many arcade PCBs use and for which an arcade technician is expected to adjust the display.

Sumez wrote:
the CPS2 has a more awkward horizontal resolution, considering it's still running on 4:3 monitors:

psycopathicteen wrote:
I do wonder if Capcom's development set used computers with their weird PAR.

Incidentally, the pixel aspect ratio of CPS and CPS2 is very close to the 3:4 PAR of the Commodore 64 and Apple IIGS super hires.

For X68000's monitor, Wikipedia's article claims 15 kHz, 24 kHz, and 31 kHz modes, one of which has 640x480 square pixels. In this case, zooming by 3x4 would theoretically fit 213x120 pixels of a sprite sheet on the screen at essentially correct PAR.


Top
 Profile  
 
PostPosted: Sat Nov 25, 2017 3:20 am 
Offline
User avatar

Joined: Thu Sep 15, 2016 6:29 am
Posts: 444
Location: Denmark (PAL)
CV1000 games run at a fairly "normal" resolution (I think it's actually perfectly 4:3), I was referring to the game they made for the PGM system (Daioujou, Espgaluda and Ketsui), though other shooters for PGM obviously have the same issue - not sure if there are any except from Bee Storm.

I don't understand what you are asking though? I've run some PGM games through a supergun, and they show up fine on my consumer TV, with the expected overscan. My supergun doesn't convert JAMMA to NTSC though, not sure why you'd want them to do that. Sounds like a horrible thing to do. :)


Top
 Profile  
 
PostPosted: Sat Nov 25, 2017 3:56 am 
Offline
User avatar

Joined: Fri Nov 12, 2004 2:49 pm
Posts: 7312
Location: Chexbres, VD, Switzerland
tokumaru wrote:
Why would anyone target CRT displays in 2017? Sure we keep them around for the old stuff, but it's only a matter of time until it becomes impossible to find a working CRT.

By this reasoning, it's only a matter of time until it becomes impossible to find any working digital device or anyhting that uses electricity to function...


Top
 Profile  
 
PostPosted: Sat Nov 25, 2017 4:11 am 
Offline

Joined: Tue May 28, 2013 5:49 am
Posts: 916
Location: Sweden
What do you mean? People are throwing away CRTs all the time and I don't think I've seen a newly produced CRT TV in years. It's still easy to find a PAL-only CRT TV, but the good ones with NTSC support are more rare.


Top
 Profile  
 
PostPosted: Sat Nov 25, 2017 4:13 am 
Offline
Formerly WheelInventor

Joined: Thu Apr 14, 2016 2:55 am
Posts: 1114
Location: Gothenburg, Sweden
The point isn't if devices break or not. The point(s) are these:

-Electronics break with age and use, so older equipment may be sooner to break.
+counterpoint: but older equipment was often made with made-to-last components, designs and techniques, unlike the designed for the dump philosophy of today
+and when something break, it's often the matter of replacement of a single or a few components. If they're not smd/smt; easy peasy provided you can identify the problem.
-But it doesn't matter. When something breaks, most people drive it to the dump, not for repairs.
-Most of all, people drive their crt:s to the dump anyway, functioning or not, because they aren't used anymore and/or because they want something newer. What we see is a rapid diminishing of the existence of CRT screens.

EDIT: Pokun beat me to it.

Maybe NESdev shouldn't be designing a new console, but a new retro gaming monitor :wink:

_________________
http://www.frankengraphics.com - personal NES blog


Top
 Profile  
 
PostPosted: Sat Nov 25, 2017 6:17 am 
Offline
User avatar

Joined: Thu Sep 15, 2016 6:29 am
Posts: 444
Location: Denmark (PAL)
I'm absolutely certain we will see new production runs of CRT monitors in the future - targeting collectors, fans of retro electronics, retro arcades, etc.

They will most likely be very good quality, but also extremely expensive due to a lack of mass production. Just like how new dot matrix displays are more expensive nowadays than a much higher resolution full color LCD screen.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 124 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8, 9  Next

All times are UTC - 7 hours


Who is online

Users browsing this forum: Memblers and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group