pros & cons... 16 bit cd games.

[awack]

There is a discussion over at the sega 16 forums about CD vs cartridge, i brought up that there are some pce cd games that will load information during gameplay so i decided to see how far it went, the one game i knew that did this was Tenchi wo Karau...just look at the variety in the backgrounds.

lets test it.

these shots are all from the first level.






i didn't feel like going back and taking shots of the first level, but it applies to every level...you can see that tiles start to drop until none are left.



last level







 

[esteban]

Aside: so first tell me what you think about the game. I've never played it.

[override]

Im not sure I follow, but are these pics of the same game on two diff systems? or are these straight pics of just that specific PCE game?

[awack]

I'm not sure I follow, but are these pics of the same game on two diff systems? or are these straight pics of just that specific PCE game?

Didn't have much time when i did this, its from the same game.

The pce super CD has 256k of memory(also 64k for adpcm sound), for a lot of games thats all you get for each level or its split into two parts, level plus boss fight....once the CD music is playing you cant load any more information from the CD. I wanted to know how many games get around this, one of the ways i know of is to use psg sound instead of streaming the music from the CD, Tenchi wo karau uses psg sound and therefore can load a wider variety of bg tiles than most 16bit games per level.

Another way is to stop the CD music every three screens or so, Beyond Shadow gate does this, which gives it highly detailed backgrounds.

Aside: so first tell me what you think about the game.  I've never played it.

I like it, you have four characters to choose from, there isn't a lot of variety to the gameplay but because there are so many enemies on screen it doesn't become dull.

I'm postsing some shots of the first level to show what happens if you stop the pce from accessing or reading from the CD, as you can see you start to lose background tiles/graphics as you progress.

[Tom]

 awack: Cool find

 I had looked as this game before because of it's horrific unnecessary mangling/use of sprite overlaying causing lots of flicker. I'm not sure why they didn't choose the lower res of this game. I mean, they scaled/redrew the sprites anyway - so it's not a big deal to do it for lower res mode. You gain more sprite bandwidth (i.e. less flicker). The other thing that I noticed was that the game uses large sections of 16 color areas, instead of optimizing for PCE's girth of onscreen colors. What I didn't notice is what you found.

 Taking a second look, it's pretty interesting. The game logic and sprite movement is all done on a 30hz system (instead of a 60hz like most games). The background itself scrolls as 60fps res (vblank interrupt routine does it), but everything else is tied to 30fps res. This means the game can request/read a single 2048k of tiles into vram with a system card call for the in between frames. Even frames = sprites/game logic, off frames = read from CD buffer. Since the screen is auto scrolling, timing isn't an issue. Seek time isn't an issue either since all the level/tile updates inside the level are stored on the CD sequentially.

 Besides some of the short comings like not using more colors (or better palette choices) and sprite optimization, it's a pretty clever game system. On a side note, this game could have been easily hacked to run on an Arcade Card setup and change the audio routine to play CD tracks.

 Edit:
 Funny thing. Looking over the first level 256k ram chunk, there's definitely enough room in there in the chunks of free space - for all the updates of the first level. I think I counted 16 updates of 2k each for the first level. I beginning to doubt that this game actually needed this CD read mid level system.

[WoodyXP]

Now that would have been awesome.  I love the Arcade's soundtrack, the PCE version is a little 'meh'.

On a side note, this game could have been easily hacked to run on an Arcade Card setup and change the audio routine to play CD tracks.

[awack]

I had looked as this game before because of it's horrific unnecessary mangling/use of sprite overlaying causing lots of flicker.

Here are a couple of shots that show overlapping sprites, the riders leg will cut out every other frame.

Seek time isn't an issue either since all the level/tile updates inside the level are stored on the CD sequentially.

That definitely makes sense.

Funny thing. Looking over the first level 256k ram chunk, there's definitely enough room in there in the chunks of free space - for all the updates of the first level. I think I counted 16 updates of 2k each for the first level. I beginning to doubt that this game actually needed this CD read mid level system.

Interesting, the reason i knew it was doing something different was because of the variety in the backgrounds in each level, if you look at the screen below you will see that the sprites are very small(though a crap load of them) and only have two frames of animation for their run/walk so i wouldn't think a lot of memory is dedicated to that.




For comparison I'm putting up some shots of its closest competition.

Variety in background, 1st level, beginning to end.








This is just to show the game with less washed out colors, magicengine.

[Black Tiger]

Does Altered Beast do the same thing?

It's a pretty goofy idea to stream stuff but still give riders and horses separate overlapping sprites. Maybe they just ported over the sprites directly from the arcade and didn't bother to merge them?

[awack]

They did a great job on the backgrounds, the sprites on the other hand.

pce                                                         arcade

Does Altered Beast do the same thing?

It definitely loads info during gameplay, but its different than tenchi o karau, it will either start dropping sprites and crash or stop at the transformation screen., this is just an indication of what happens, emulation isn't exact.

[Tom]

 awack: You're right. The home port does retain a lot of the detail of the arcade version. Pixel for pixel the majority of it.

 Below: Arcade image in PCE's palette - compared to the PCE.

<- 104 colors
<- 93 colors

 The guys on the horses, yeah - mean ol' sprite overlaying. They should have merged them. The weapon of the main char is also overlaid :/

 The other guys, missing sprite frames should have been there - there's room in vram for them:

^- red colors show free vram for sprites (taken from vram snapshot of mednafen debugger)

[awack]

Below: Arcade image in PCE's palette - compared to the PCE.

Damn, they are close.

The guys on the horses, yeah - mean ol' sprite overlaying. They should have merged them. The weapon of the main char is also overlaid :/
 The other guys, missing sprite frames should have been there - there's room in vram for them:

NEC Avenue...unlike backgrounds which they where really good at, they didn't seem to be the best at sprite handling,animation/effects....sounds like this game could have been even better.

[Black Tiger]

NEC Avenue...unlike backgrounds which they where really good at, they didn't seem to be the best at sprite handling,animation/effects....sounds like this game could have been even better.

Super Darius/Darius Plus is another game with needless overlapping sprites (for the bosses). If they really wanted to save some space on the bosses for the HuCard so be it. But the CD version should've merged more, especially since the game reloads before each boss.

[Tatsujin]

damn the foregrounds are 99.9% arcade adapted just shame on the lil' sprites that had could been an almost 100% accurate port.

may you post some morer straight pce<>arcade comparisons

[Tom]

damn the foregrounds are 99.9% arcade adapted just shame on the lil' sprites that had could been an almost 100% accurate port.

 If they had merged the sprites and kept the same restraints (or a lack thereof) for sprites, they could have been made bigger.

[awack]

may you post some morer straight pce<>arcade comparisons

Check out page 5 of pce vs gen vs snes thread to see the genesis port.

chiki chiki boys

pce                                                                   arcade