Rolling Thunder - Amiga Port

[mcgeezer]

So I'm seriously considering porting Rolling Thunder.

The problem is the target platform.

It's either got to be a stock A500 with 0.5mb ram expansion or an Amiga A1200.

Looking at the arcade game closely the animation in the sprites are deceptively detailed (i have not actually been able to get a hold of the ripped sprites (yet).

So for an A500, the frames in the sprites would need to be cut back making the game less arcade perfect, something I'd have to consider but then it would get shit thrown at it.

A1200 I'm pretty sure I could make a perfect port, but then it will also get shit thrown at it for not running on an A500.

I'm not really into doing both as that would be a huge amount of work.

The enemy sprites have ALOT of frames that would eat chip ram.

[ Show youtube player ]

So, RT on A500 or A1200?

Geezer

[Galahad/FLT]

Originally Posted by mcgeezer

So I'm seriously considering porting Rolling Thunder.

The problem is the target platform.

It's either got to be a stock A500 with 0.5mb ram expansion or an Amiga A1200.

Looking at the arcade game closely the animation in the sprites are deceptively detailed (i have not actually been able to get a hold of the ripped sprites (yet).

So for an A500, the frames in the sprites would need to be cut back making the game less arcade perfect, something I'd have to consider but then it would get shit thrown at it.

A1200 I'm pretty sure I could make a perfect port, but then it will also get shit thrown at it for not running on an A500.

I'm not really into doing both as that would be a huge amount of work.

The enemy sprites have ALOT of frames that would eat chip ram.

[ Show youtube player ]

So, RT on A500 or A1200?

Geezer

A500 no doubt.

1 Meg of any mem should be more than enough, most of the enemies are the same animations just different colours, its a multi directional scroller, but, it seems to limit that quite extensively throughout the game. Lots of horizontal movement, then a bit of downwards and then continue horizontal, its not like Turrican where thats a true free roaming multi directional scroller, Rolling Thunder seems to strictly limit those multi directions.

Most of the background graphics are bland so I can't see that being too much memory.

Store highspeed graphics in chip mem (i.e. bobs), and store low speed stuff in slow ram (i.e. background blocks if you're just copying into the border just before they come onscreen.

Score overlays as sprites like Parasol Stars does, i'm pretty sure 32 colours with later changes in the palette would be more than enough.

For those anim frames that are more than colour changes, those characters appear in later levels so just a reload is required from disk.

Rygar was a different proposition, it was never done on Amiga, and that gave you entirely the freedom you needed to do it.

However, my own personal feeling is that Amiga A500 owners were utterly robbed by what Tiertex released, and we all know the Amiga could have done significantly better, and I feel that should be the focus, otherwise, to my mind, its giving Tiertex an out, its saying "See, it could only be done on an AGA machine that wasn't released back then."

IMHO

[mcgeezer]

Yeah, you’re right Galahad (about the Tiertex bit)

I suppose i could hold the sprites in 3 bitplanes, but i might be able to set the palette such that i blit into different planes to change the colours.

So enemy colour 1 i blit into planes 1,2,3
Enemy colour 2 i blit into 2,3,4
Enemy colour 3 i blit into 3,4,5

That should save on a shit load of memory and allow me to keep a 5 bitplane mask for speed.

Agree about tiles and game code in slow ram.

Scrolling is 8-way any direction.

[Amigajay]

Yeah i agree A500 target be nice as everyone could play it that way, and as much as Rygar is a great port, it was more a given (no disrespect) that the A1200 was capable of doing it justice, so to have a much better port of RT for the A500 sounds awesome!

But either is great if you decide AGA i wouldn’t bloody grumble!

[d4rk3lf]

A500 would be great!

Originally Posted by Amigajay

Yeah i agree A500 target be nice as everyone could play it that way,

This.

[DamienD]

Originally Posted by mcgeezer

So I'm seriously considering porting Rolling Thunder.

The problem is the target platform.

It's either got to be a stock A500 with 0.5mb ram expansion or an Amiga A1200.

Looking at the arcade game closely the animation in the sprites are deceptively detailed (i have not actually been able to get a hold of the ripped sprites (yet).

So for an A500, the frames in the sprites would need to be cut back making the game less arcade perfect, something I'd have to consider but then it would get shit thrown at it.

A1200 I'm pretty sure I could make a perfect port, but then it will also get shit thrown at it for not running on an A500.

I'm not really into doing both as that would be a huge amount of work.

The enemy sprites have ALOT of frames that would eat chip ram.

[ Show youtube player ]

So, RT on A500 or A1200?

Geezer

One word; Shinobi

[Galahad/FLT]

Originally Posted by mcgeezer

Yeah, you’re right Galahad (about the Tiertex bit)

I suppose i could hold the sprites in 3 bitplanes, but i might be able to set the palette such that i blit into different planes to change the colours.

So enemy colour 1 i blit into planes 1,2,3
Enemy colour 2 i blit into 2,3,4
Enemy colour 3 i blit into 3,4,5

That should save on a shit load of memory and allow me to keep a 5 bitplane mask for speed.

Agree about tiles and game code in slow ram.

Scrolling is 8-way any direction.

It is...... and its not

What I mean is yes, it scrolls in all 8 directions, but if you pay close attention to the way the levels are structured (certainly what i've seen so far), the game seems to restrict those directions through level design.

In Turrican, you could goto the top of a level and jump off a solitary block and fall down and go in different directions, but Rolling Thunder seems to restrict it quite a bit, there doesn't appear to be many open spaces for big jumps, i'm guessing it does it because of memory concerns and whether the arcade hardware can keep up.

It could be my imagination, but i'm wondering just how big are the levels in the first place?

EDIT: Yup, as I guessed, you could massively cheat on this game, the only slightly tricky area is area 9, all the rest of the levels are stupidly easy, you wouldn't need to do a corkscrew scroll routine or anything like that.

Goto: https://vgmaps.com/Atlas/Arcade/#R

And go down to Rolling Thunder, and you'll see what I mean by the structure of the levels, you could literally just blit strips from the very top of the level to the bottom, and then adjust bitplane pointers to scroll up and down.

[Hewitson]

I'm going to disagree and say the target platform should be the 1200, simply because it would be capable of doing a better conversion of the game.

[Minuous]

If the point of the exercise is to show that the Tiertex conversion is poor, the reconversion should run on the same configuration (512K A500). Otherwise no direct comparison between the versions would be possible.

[Hewitson]

Originally Posted by Minuous

If the point of the exercise is to show that the Tiertex conversion is poor, the reconversion should run on the same configuration (512K A500). Otherwise no direct comparison between the versions would be possible.

It's painfully obvious that the Tiertex conversion is shit, theres no need to prove anything about that.

The focus should be on making the best game possible instead of proving a useless point that everyone already knows.

[manossg]

I would also prefer the best game possible, so my vote goes for A1200.

[CFou!]

Originally Posted by manossg

I would also prefer the best game possible, so my vote goes for A1200.

idem

[vulture]

a500 1MB imo

[Galahad/FLT]

Originally Posted by Hewitson

I'm going to disagree and say the target platform should be the 1200, simply because it would be capable of doing a better conversion of the game.

The A500 can do Rolling Thunder in its sleep, absolutely NO requirements for A1200 whatsoever.

[roondar]

A better A500 port would be nice to see

[Asman]

IMHO: It is not so obvious for me. Main hero Albatros is sometimes 64 width, usually 48 width, height is about 64 pixels. Enemies Maskers: 32 width x 64 height. When I played on MAME I count about 10 enemies in later levels(6 or more). In total 11 objects + bullets/granades + open/close doors + fan. Moreover balcony + mesh fencing complicate a bit, because enemy mask must be "and" with inverted balcony/mesh mask.
I am very courious what technique will be best for this game. Some enemies as sprites with multiplexing (like maskers who throwing granade down) or just hero as sprite and what about bullets.

[Solo Kazuki]

@Asman
For You it's obvious, probably for McGeezer also. But it's next opportunity to start next "why it requires AGA" quarrel...

[mcgeezer]

Originally Posted by Asman

IMHO: It is not so obvious for me. Main hero Albatros is sometimes 64 width, usually 48 width, height is about 64 pixels. Enemies Maskers: 32 width x 64 height. When I played on MAME I count about 10 enemies in later levels(6 or more). In total 11 objects + bullets/granades + open/close doors + fan. Moreover balcony + mesh fencing complicate a bit, because enemy mask must be "and" with inverted balcony/mesh mask.
I am very courious what technique will be best for this game. Some enemies as sprites with multiplexing (like maskers who throwing granade down) or just hero as sprite and what about bullets.

And this is what worries me, some of the enemy animations are huge.
I'll take the first step and extract all the graphics and see where things stand.
I'll report back here but it isn't clear cut - however I am keen on a "what could have been scenario for the A500".

[roondar]

Originally Posted by mcgeezer

however I am keen on a "what could have been scenario for the A500".

Yes, this is exactly why I "voted" for an A500 port. It would be interesting to see how close it can get

[d4rk3lf]

Not sure how this relevant is, but Amiga game Deliverance had a very large sprites.
I was very impressed when I discovered it recently.
Works perfectly on A500

[ Show youtube player ]

Yeah, the sprites are probably 25fps... oh well... that's why I said I don't know how relevant is.