Spectrum Computing

highrise wrote: ↑Mon May 13, 2024 3:51 pm Interestingly, Moon Cresta was actually the first officially licensed arcade conversion for the Spectrum.

Is this a joke I don't get? I thought we all knew it was Hunchback?

I noticed there's a slight graphical glitch in Galaxian arcade... don't know if it happens all the time or only some of the time.

I managed to pause the youtube video on the exact frame one of the aliens started swooping and it disappeared for a frame. So it looks like there may be a 1 frame gap between the alien leaving the static sheet and being added to the swoop list (again, I think only 1 disappeared so it may not happen always, maybe the aliens start swooping 1 frame apart though?).

Not that it would matter for a conversion I'd rather it didn't do that though

Ok my attempt at a sheet shoot em up is underway, day 1 progress.



Red border is how long it takes to redraw everything.

* Drawing each row at a time instead of each column. I think it will be fast enough to manage it. I'm going to need to draw 1 extra alien on each side I think though to handle erasing of stuff on the edge when they move

* Nothing is moving yet but it is drawing all that each frame

* I think the galaxians need to be closer together (might try 12 pixels apart instead of 16 pixels apart) - that will make the galaxian colours a bit weird though I think

* It's completely unrolled (as in each line it draws is completely unrolled lol, no loops at all) although it does do an indirect memory access which I can probably replace by working out the correct graphics to poke for the next frame into the LD REG, (graphicsaddr) instructions to just be LD REG, graphicsdata, via self modifying code.

* everything is put to the screen using the stack (and it's all PUSH there are no POP instructions since I know what graphics to load into the registers I push).

* next step is to turn the line drawing into a macro so I can position stuff at arbitrary Y coordinate (currently using Y offset of 0 or 4 from the top of a character row). I'll need to change that to see how it looks if they are 12 apart rather than 16 apart.

I'll probably open another thread in programming when I start animating them.

They are 12 apart in Y direction I might try 10 instead.

That probably won't fit well with the attribs though. Main thing is getting the bottom 3 rows to be same colour I guess and the top one to be mainly yellow. I'll probably do a stripy attribs thing to see what might look best.

I can't squash them up in X direction cos of the stack being used to draw the pixels.

Tomorrow I'll at least get the top row moving (probably none of the other rows they are more complicated - top row does not animate at all)

@highrise do you want the thread splitting? From around here it started morphing into a Galaxians thread.

I just realized i did not know Pacman had these many cutscenes!
I especially liked what you did with the 3rd cutscene maintaining the yellow and the red separate and keeping a smother movement (than a 8 pixels jump): great job!
plus: you used the "one pixel up-one down/one pixel left-one right" (that is what i call it) technique (I first saw this in DEATH SQUAD's games like Thunder turd, Dung Darack and others) which makes the parts of your sprite more interconnected

GREAT JOB!!

Pleeeeease, try to make the game much more evolved compared to the old Galaxians: more weapons, upgrades to the ship, more ships, animations and colors for aliens, two players at the same time, etc. I think that such improvements are desired by the whole community. Also, you may add an option: Classic game and Modern game (with improvements). Just a suggestion, I love your work.

I imagine it would be a doddle to design the aliens so they bridge two rows of attributes, so you could then have, say, the top 2/3 of an alien one colour and their lower few pixel rows and dangly bits another colour? Cheap effect without any multicolour hacking.

ok, let's get back to the topic, full game playthrough.

ionut76 wrote: ↑Thu May 16, 2024 10:36 am Pleeeeease, try to make the game much more evolved compared to the old Galaxians: more weapons, upgrades to the ship, more ships, animations and colors for aliens, two players at the same time, etc. I think that such improvements are desired by the whole community.

No they're not. Please please don't.

highrise wrote: ↑Thu May 16, 2024 2:56 pm ok, let's get back to the topic, full game playthrough.

That is looking pretty darned excellent, although starting on a score of 9,810 is somewhat unconventional

thanks, yes, I think I was testing the high score bell or something

testing the 'Plus' mode.

What's with the ghosts not moving first time you eat a power pill? It worked fine 2nd time you did it.

I don't know if you've read the youtube blurb but this is a different game mode, when you eat the fruit you get random effects.

Rather than replicate Pacman plus exactly, I decided to riff on it a little and have a bit of fun with it. In this version, the game is faster and it is the fruit that generate random effects. The following effects can happen when eating a fruit:

1) All the ghosts turn blue and freeze. This works but I need to stop the eyes from freezing, which I will fix shortly.
2) All the ghosts turn blue and temporarily invisible. This is from Pacman Plus.
3) All the ghosts turn blue and the whole maze turns invisible. This is also from Pacman plus.
4) Pacman turns green and is temporarily invincible and can pass through ghosts.
5) Pacman flashes red and yellow and can move at twice his normal speed.

Nope I watched it embedded so that's why I didn't see the blurb.

If you do that maybe you should consider wandering fruit like in Ms. Pacman as well?

initially I just wanted to implement Pacman Plus and added a few more features and I'm pretty much all-Pacced out now I do have Ms Pacman pencilled in to do next year maybe, as well as Crazy Otto.

I'm confused. Last I heard you were bug testing the game, but this video says it's released and he plays it.

Strangely, though, he credits the release to "Midnight Brew" and makes no mention of either your name Allan Turvey, your publisher name "Highrise", or your brand name "Happy Coding"! Do you go by four names? (I'm confuuuuuused.)

yes, I guess it has got a bit complicated, but I will explain.

Highriser was my coding name and my itch.io shop name, i.e me
Happy Coding ZX was my Youtube and Facebook group name, i.e my work
Midnight brew is the publishing company which I run, which publishes my games as well as those of some of my friends.

However, a lot of people started calling me Happy Coding, so I don't use highriser any more. Now it's just me, Happy Coding the coder, and Midnight Brew the publisher. I changed my itch page to reflect this too.

As for the video, you will note as he says in the video that it's a preview copy - I send preview copies out to channels I appreciate so they get a little scoop and show the game before it is released. Although my games are commercial, I often give them away to fellow coders, Youtubers and so on.

I hope that explains it all! The game is out by the way...

This is a thing of exceptional beauty. The presentation is stunning - the bezel REALLY makes it pop visually - the speed and smoothness impeccable and the sound excellent. The stylish title screen, boot sequence and cutscenes round off the package. We've come an incredible distance in a couple of years, from the primitive Atarisoft version to Pac-Hack to Pac-Man ZX Arcade (and via the emulated +3 version) to this, each one a huge leap over the last.

Nitpicks: the first couple of levels seem overly fierce, both in terms of ghost speed (mostly Blinky) and how short the powerpill duration is. In the arcade it was pretty easy to get 1600-point ghosts on the Cherry and Apple stages (I'm always slightly disappointed not to hit a max 14,800 on level 1), here it seems close to impossible. And it's a shame the "safe spot" isn't implemented. But it's much better for a simple arcade game to err on the side of too difficult than too easy, and there's always Casual.

This should be the benchmark for converting portrait-mode arcade games to the Speccy from now on (especially the bezel aspect). I'd love to see someone do a more complete, machine-code version of the highly playable BASIC Frogger that took the same approach.



But for my money this is THE best Speccy port of Pac-Man, better-looking than even the emulated one, and running on a humble 48K to boot. Fantastic work.

Yeah looks top notch work, well done. (I also noticed the power pill timer seemed a bit off). If there's a pause you don't really need the safe zone implemented... I read how it's supposed to work but I'm sure it would still be possible to go around anticlockwise to reach Pac Man when in the safe spot as I read it?

Don't make too much money off it or Namco lawyers may have something to say about that lol

I'll probably do a bit more on Galaxian soon now I'm over my Scrabble mini-obsession I started on Friday night/Saturday morning

Thanks guys. Although the game is released, it's certainly not complete because there's no better testing that in the wild. What I would say is:

- The safe zone was implemented quite early on, so I'm not sure why it has stopped working. I'll have to investigate.

- All the timings for the blue ghosts are based on the 'pac-man' dossier, but I'll check them again as well.

ok, I checked the blue ghost pill timings and I think it's out by about a second so I've added that.

There is definitely a bug in the 'cyan' ghost logic that seems to have creeped in from somewhere. If you watch this video you'll see the safe zone and ghost logic was fully working. These things happen, and I will sort it.

Have you adjusted the timings for 50fps as well? I would have thought timings would want to be in frames rather than seconds since the arcade runs at 60fps. Unless you scale the movement speeds up as well I suppose.

I wonder if Ms. Pac-Man is on the list of future considerations?