Street Fighter 1 - Scorpion Engine

[mcgeezer]

Originally Posted by jotd

that's the most annoying part of a fighting game: character "compression" and also collision masks (you have to create some hit zones and some invincible zones else if for example you get punched in the leg you're attacking with, you're hit...).

There's a good reverse of SF2 collision system around. It's a lot of work to input such data.

not to mention the A.I. that you have to reverse more or less faithfully or the game isn't going to look like the original. A fighting game is never a piece of cake, even with Scorpion, because the hard part is the logic, not the basic blitting or animations.

Personally after I'm done with Karate Champ (if I can make it work) I'll take a vacation redoing Pengo or Phoenix or some other very simple game...

I'm with you on this, now speaking from experience this type of game is very difficult to get right, I probably now know a fair amount about it too and I didn't even use a Z axis on my game.

Memory is nearly always a factor... split your blits up to save on dead space, don't use interleaved blits if you want to go 25 frames and save memory. Your sprite routine should cookie cut from back to front.

Have a good and simple "data driven" way of handling enemy AI to apply the logic.

Your collisions must be absolutely spot on... if you're double buffering remember your collisions in code are one frame behind what you see on screen ( at least for me anyway)

Apologies for the ramble, my brain is fried at the moment.

[Tsak]

Originally Posted by saimon69

Blocky Skies was available for the unexpanded A500, made by Alpine9000 in 2016, you can check with him

I know but this has nothing to do with the question. I bet there have been other games as well which don't require more than 512k simply because they have lightweight gfx & music.

Besides that it's up to the dev basically. I can imagine some people might want to go with this restriction just for the challenge. However in my 15 years being an Amiga game dev and community member I don't remember anyone ever asking for plain 512k support. And while the subject is often mentioned in relative dev discussions, it's pretty universal among Amiga people that 512+512k for A500 IS the definitive standard. Would you disagree?

[saimon69]

Could but would not

[Tsak]

Originally Posted by mcgeezer

But we do it anyway because as developers we understand the boundary of what was possible when the Amiga was mainstream. This is what makes the gamedev a challenge on the Amiga.

I couldn't agree more.
However truth is it's not that often we see Amiga games and game devs targeting 512k in general. Especially if said project is a port from a more advanced arcade where you already have to compromise a ton of stuff.
And remember, we're also talking about Scorpion here. Would you as an experienced ASM coder ever consider going for 512k for a project like SF1?

[alain.treesong]

Of course, an A500 is 512K of chip memory and 512k of fast (aka slow :-) ).
In 1991+, almost every Amiga 500 users bought the 512K fast extension because games and demos needed it.
Games before 1990 requires only 512k total (chip) but this was often to the detriment of the sound and sometimes added painful disk access.
Obviously Turrican 2 (end of 1990) for example or Lotus 1 (1990) work only with 512k :-)
Anyway, I know I'm repeating myself, the problem is the Chip memory and 16 colors for the characters, it will be very very hard to do. Even with 8 colors, it's not obvious but more realistic.
For information, in the "New Impact" demo, I use all the chip in the Ryu vs Ken scene and I don't have half the movements of the arcade version (and of course I'm in 8 colors).

[Galahad/FLT]

Originally Posted by Tsak

I couldn't agree more.
However truth is it's not that often we see Amiga games and game devs targeting 512k in general. Especially if said project is a port from a more advanced arcade where you already have to compromise a ton of stuff.
And remember, we're also talking about Scorpion here. Would you as an experienced ASM coder ever consider going for 512k for a project like SF1?

For me it wouldn't be a consideration, 1 meg is the default, 99.99% of Amigas had it, restricting yourself with only 512k just seems like a self imposed handicap that at some point the programmer will have to concede.

Tiertexs version isn't crap because they were restricted to 512k, its crap because no care or effort was expended in doing it.

I understand some people want to restrict themselves to what the original developers had, but it just feels self defeating and will lead to a conversion that isn't the best it can possibly be, which is surely the entire point in revisiting them.

[malko]

^ +1

[mcgeezer]

Originally Posted by Tsak

I couldn't agree more.
However truth is it's not that often we see Amiga games and game devs targeting 512k in general. Especially if said project is a port from a more advanced arcade where you already have to compromise a ton of stuff.
And remember, we're also talking about Scorpion here. Would you as an experienced ASM coder ever consider going for 512k for a project like SF1?

I might not have been exactly clear in my post, but yeah I consider 512/512kb the norm for a base Amiga.

In game dev terms I'm nearly always more impressed when coders start with a memory footprint of what they intend to do in a game because it's generally always the starting point. However I also appreciate that it's far from easy and the appeal of Scorpion engine is great for the Amiga community even if stuff won't run on stock hardware.

Originally Posted by Galahad/FLT

I understand some people want to restrict themselves to what the original developers had, but it just feels self defeating and will lead to a conversion that isn't the best it can possibly be, which is surely the entire point in revisiting them.

Rightly or wrongly I personally do it to prove to myself that I had the capability to do it, and with a bit of mentoring I could have been a games programmer back in the day. I sometimes regret that I wasn't but my circumstances at the time just didn't work out for me.

I'm not joking when I say I could have had Devils Temple released 6 months ago had it not been for the memory constraints I'm working under.

[jotd]

All my arcade remakes of early games (early eighties) need 512k+512k to run except Pacman that needs 512k chip only. I could reduce memory footprint by using lower resolution sounds but what the hell...

On the other hand I didn't optimize Karate Champ memory and now it's requiring 2MB... for a 1984 game... That sucks. Part of the explanation is 1) I didn't even try to decompose large character sprites (that only use 2 bitplanes though) and 2) original game has a free symmetry by being able to blit the tiles from left to right or right to left. In that aspect, portrait mode has an advantage on Amiga display as the blitter can work in reverse order, but only in Y.

So it's very difficult to make a game run in 512k/512k and requires extra efforts, that devs back in the day had to endure. And sometimes they used 512k expansion in a very subtle way. I only recently found out that Cadaver had slightly more sfx with 1MB than with 512K. Never noticed before...

[Tigerskunk]

The Amiga opens up a lot at 512k/512k.

I mean, I have the highest respect for people back in the day who were able to cram all that shit into 512k chip like SotB for instance, but damn, having those 512k extra for code and tiles leads to so much more fidelity in games.

[acidbottle]

If anyone is sat there with a stock A500 with 512k they are not even getting to enjoy the full catalogue of great games that released back in the day!

1MB, especially in 2022, should be a bare minimum, surely. Have to tip my hat to coders who cram some great games into 512, especially ports, takes a lot of skill and patience.

[jotd]

Jim Power code (not including TFMX replayer) makes sure it doesn't go over 32Kb for the game code, has a kind of overlayed code (some code parts are level-specific and are loaded with the level) so it can use word pointers, be faster (on chip) and use less space.

The result is a game running with 512k that could have needed 1MB.

[CCRider]

Originally Posted by Tigerskunk

The Amiga opens up a lot at 512k/512k.

I mean, I have the highest respect for people back in the day who were able to cram all that shit into 512k chip like SotB for instance, but damn, having those 512k extra for code and tiles leads to so much more fidelity in games.

SotB could have well wasted an extra half meg implementing a more interesting gameplay code...

[saimon69]

You forgot the mindset of people back then: they (and me) thought "if they can do miracles with 38k/41k on the speccy and C= 64, why does it needs more than 512k to do the same on an Amiga/ST?"

Well, because words/longwords instead of bytes? 16-bit 512k does NOT equate to 8-bit 512k unfortunately: 512k on an 8-bit machine can be compared to have like eight megabytes of chip RAM in an Amiga: plenty! (despite paging)

[Tigerskunk]

Originally Posted by saimon69

You forgot the mindset of people back then: they (and me) thought "if they can do miracles with 38k/41k on the speccy and C= 64, why does it needs more than 512k to do the same on an Amiga/ST?"

Well, because words/longwords instead of bytes? 16-bit 512k does NOT equate to 8-bit 512k unfortunately: 512k on an 8-bit machine can be compared to have like eight megabytes of chip RAM in an Amiga: plenty! (despite paging)

Mmmh, I think thats definitely not directly comparable.

Bitplanes use every single bit, for instance.
I guess sounds do the same.

The C64 is a bit special, since it's kind of a tile based machine with its charset. Almost like consoles.
Needs a lot less memory for that than setting up four 8k bitplanes for 320x200 to get 16 colors.

Same with sounds. Those samples just take so much memory.

The Amiga needs almost all of its chipRAM just for keeping decent Blitter assets, bitplanes and sound+music.

Those additional 512k do wonders if you don't need to cram your code and tile assets into chip

[saimon69]

Originally Posted by Tigerskunk

Mmmh, I think thats definitely not directly comparable.

Bitplanes use every single bit, for instance.
I guess sounds do the same.

The C64 is a bit special, since it's kind of a tile based machine with its charset. Almost like consoles.
Needs a lot less memory for that than setting up four 8k bitplanes for 320x200 to get 16 colors.

Same with sounds. Those samples just take so much memory.

The Amiga needs almost all of its chipRAM just for keeping decent Blitter assets, bitplanes and sound+music.

Those additional 512k do wonders if you don't need to cram your code and tile assets into chip

Hybris (and maybe Battle Squadron too) had this nice idea of storing 8x8 subtiles and creating 16x16 tiles on the fly in RAM from those assets; that method could be used even today if made the right way - that or storing game assets as vectors and rendering in a vectorbob (latter might work better with faster CPU though)

[msmalik681]

for now I am targeting the 1MB amiga 500 but without tile based graphics it will be over. I can handle the graphics and the sound effects just need help with the music as the amiga uses such a odd music format.

[saimon69]

Originally Posted by msmalik681

for now I am targeting the 1MB amiga 500 but without tile based graphics it will be over. I can handle the graphics and the sound effects just need help with the music as the amiga uses such a odd music format.

Please Define "odd" - normal midi would not do the cut because needs at least eight channels to sound good, so songs need to be rewritten in protracker format, plus scorpion does not support midi as far as i know.

By the way mod is not THE standard of amiga music, just the "de facto" standard

[alain.treesong]

Originally Posted by msmalik681

for now I am targeting the 1MB amiga 500 but without tile based graphics it will be over. I can handle the graphics and the sound effects just need help with the music as the amiga uses such a odd music format.

To clarify, amiga 1mb = amiga with 1mb of chip or with 512K chip/512k fast ?

[Tigerskunk]

How is mod "odd"?
It's just sequenced samples.