Robocop AGA
 

Initial Update / Background

As I've enjoyed following the development threads for the likes of Rygar, Kung Fu Master, Pacman, Turrican 2 AGA etc. I thought I'd create a thread to document progress of my Robocop port for AGA Amigas.

Although I've been a high-level programmer for 20-odd years now, this is my first delve into 68k ASM and utilising the Amiga hardware by "banging the metal", and I must say it's bloody hard work!

I started with Photon's startup code and tutorials, and over the past 18 months have tinkered on, bent more experienced coders' ears (quite a lot) and through experimenting with various other ports and ripped graphics, settled on Robocop and came up with what we have today.

Now, please don't expect updates or the general development progress that you're used to seeing from the likes of mcgeezer, jotd or Muzza... I have nowhere near the experience that those guys have but I'll try and keep on top of this and post progress when I can.

The current engine is nothing special; it runs in 64 colours, utilising 64 pixel wide sprites for the background parallax on level 1, and a 4x fetch mode. Graphics were converted from the arcade originals, and reduced down with Paint and Photoshop into various banks of 16 colours; Robocop is 16 colours and I think the background right now is 32 colours although I could be wrong.

I use PPaint and PicCon on the Amiga, and Photoshop, Tiled and Aseprite on the Mac. Emulation is with FS-UAE.

My first test engine was an initial attempt at scrolling through a map using the hardware, and blitting into an offscreen column:

https://www.youtube.com/watch?v=U-1sKhaWc98

This worked well, but I still had to implement the blitter restore routine for the main sprite. I was happy with my progress up to now though, so that head-scratcher could wait!

Update #1

So that was a quick update! I've picked up my code again recently and implemented the dreaded blitter restore routine, which wasn't as bad as I thought it would be.

It seems to work well.

I also updated the scrolling routine and fixed a few bugs in there relating to Robocop's position when he reaches the end of the level. All simple stuff really, but it needed doing.

The video here is pretty much the same as the last one, obviously with the restore routine implemented, Robocop now doesn't leave a trail behind him!

Ahhh... simple things :)

https://www.youtube.com/watch?v=OKDL_ZOSuNQ

Fantastic ! looks like the arcade, really impressive. It was one of my favorites!:bowdown

Amazing! Watched the movie a couple of nights back to. Looks like you have nailed the visuals. The potential in the AGA was never fully reached back in the days, hope you pull this one off :)

Looks stunning, more quality northern programming like with mcgeezer lol. They have the arcade cab at Leeds Arcade Club btw.

it really looks great! AGA is definitely the proper target with that one

Looking very cool. Am I correct in seeing the scrolling looking a little slower or 'steppy' in the second video?
I am looking at some ASM coding after years of JS and Python. Any suggested books to read?

This looks great and I'm happy it's being done now by 2 people, but Robocop is 100% possible on an A500, the game is pretty simple, I'd say Robocop2 on Amiga is actually beyond the arcade engine.

https://www.youtube.com/watch?v=K845O9IPAvs

I am still tempted to do an A500 port, just waiting on the A500 thread to be updated to see if the port there is abandoned or not...

Thanks for the positive comments everyone :bowdown

Probably just the screen recording and/or FS-UAE as I hadn't changed anything in the scrolling code; it remains the same. I still need to check on real hardware, but I need to get my CRT monitor fixed first.

Getting into ASM coding? Coming from a high-level language too, maybe go down the same route I did with Photon's tutorials: https://www.youtube.com/watch?v=p83QUZ1-P10 and it's wonderful "Hello, Amiga Coders" line.

you can use my Pacman Amiga port source code and try to rebuild it, then hack into it. It's pretty simple actually (Mspacman WIP source code is better because it has blitter cookie cut routines too)

There are also python scripts to generate assets in amiga raw format.

Also, if you're using macOS then I wrote a small tool to help with a few problems I came across whilst starting: http://eab.abime.net/showthread.php?t=97698

Awesome, thanks DanielAllsopp and jotd. checking it out now

You shouldn't wait but take the lead with your port. Keep it moving! :)

I quite agree ;)

(if you begin yours, it doesn't meant that the other version has to be stopped - it just means that we may finish by having two versions :p).

I am not sure I agree, the visuals on Robocop 2 are no where near the quality of Robocop arcade.

Agree with the above, robocop 2 looks inferior to first one, think the kung fu master remake looks way better than robo2, which is a fair-ish style comparison.

Not the graphics, the engine.


Skip and watch the final battle in Robocop2 on the Amiga, it's epic! Really shows off the engine.

How do you have an engine without graphics? What is that engine doing ?

I mean you can have a great engine that can quickly move things around calculate physics etc etc, but if the graphics are then mode O amtrad cpc

it's pretty tough to separate an engine from the actual game. The engine is built around the game and not the other way round.

Another way to say that is that there is no engine, only a game. You can copy over bits and pieces of it to a new game.