New version of PacMan (PuckMan) for the BBC Micro

[fwibbler]

I'm using 4.14
Just tried it on B-Em and no such problems.

[chrisn]

I suspect it has a bug in the BIT zp instruction and the AND part.

Well, there is a bug in BeebEm 4.14 (but not in those instructions). The problem was with address wraparound with LDA (zp),Y. There's more info here. Running under the debugger, I can see that PacMan executes a LDA (zp),Y that generates address &1001F, which should wrap to &001F.

The bug was fixed in BeebEm 4.15.

[tricky]

Well supported Chris, I think we spoke about that bug a little while ago, soon after you had fixed it in the latest beebem and I had fixed it in my ancient version. But in the couple of weeks since, I had forgotten all about it and didn't even think that I still used that code. It always surprises me when a bug this old shows up.

[tricky]

Added more scoring and some fruit code, although you can't collect it yet.
Known bugs!
Sometimes a ghost will get stuck in a tunnel.
Pacman leaves some crust behind when he dies or completes a level.
The first fruit is debug code and the rest can't be collected.
There are no/infinite lives.
Some bits of dots go missing or occasionally one gets drawn on the maze wall.
Probably others, that I would love to hear about.

[fwibbler]

Added more scoring and some fruit code, although you can't collect it yet.
Known bugs!
Sometimes a ghost will get stuck in a tunnel.

Haven't had that one yet.

Pacman leaves some crust behind when he dies or completes a level.

Thats happened every time I complete a level so far.

There are no/infinite lives.

This is just as well (for testing purposes).

Some bits of dots go missing or occasionally one gets drawn on the maze wall.

Thats happened a couple of times.

Probably others, that I would love to hear about.

I've also managed to go through a ghost without eating it (when it was blue) twice so far.
Apart from that, I think that the ghost change direction a little too often compared to the arcade?
Cheers!

[fwibbler]

If you're desparate for a loading screen (and if no-one does anything better) then I put this one together using Image to BBC...

[tricky]

Thanks for playing and that looks great. I don't usually go for loading screens as they annoyed me bits with tape loading.
I display some kind of mode 7 splash screen, then load the compressed game and finally change the message, or with the Trickysoft ones, display the controls until someone presses start and then launch the game.

I forgot about going through ghosts, I've only seen it when they are blue, but it is the same code either way and shouldn't be possible! You can go through ghosts in the arcade about 1 in 8 times.

[Arcadian]

I played up to 60,000 points - no crashes and no new issues (what's the last 'fruit' btw? I was expecting a key! ).

Within 10 seconds of starting I walked through a ghost (I hadn't eaten a power pill, so it wasn't deep blue). Bottom right corner heading up - Inky (blue) was above me heading towards me, Clyde right behind Inky. I walked through Inky but no such luck with Clyde - life lost (well it would have been if lives had been implemented, heh). The walking through a ghost bug didn't occur again on this try.

At approx 20,000 points, Blinky (red) got stuck in the left tunnel. No power pills left (see below) so he stayed there until the end of the level.

At approx 35,000 points, three ghosts (not Blinky) got stuck in the left tunnel. I noted this was a second or two after a power pill had expired. I then found I was able to release the ghosts by eating another powerpill.

Inky got stuck in the left tunnel and Pinky simultaneously got stuck in the right tunnel. Again, this was within a second or two of a powerpill powerup expiring - and once more, eating another powerpill released the ghosts.

So the tunnel issue is definitely related to the power pills somehow!

(I captured short videos of the above three issues should you need to see them, though only from after the ghosts had gotten stuck).

[oss003]

Walking through ghosts in the arcade version is explained here: http://forum.arcadecontrols.com/index.php?topic=69109.0

Greetings
Kees

[tricky]

Originally I was going to allow walking throughout them as per the arcade, but it feels like you were cheated if they are blue.
I added a check before and after the ghosts move, meaning that it should be impossible to walk through ghosts in any stage, but I must have the second check in the wrong place.
I'll have another look at the tunnel code, but I think I know what is causing the ghosts to get stuck, but not how it can happen if that makes sense.
I'm glad there are no new issues!
I'll check what the last fruit is.

[fwibbler]

Thanks for playing and that looks great. I don't usually go for loading screens as they annoyed me bits with tape loading.

Yes, I remember sitting there thinking that the game could have been loaded in the time taken to load that screen (particularly if it was a mode 1 or 2 screen).
But then as soon as I bought a disc drive the opposite happened. I always thought their screens would have looked better in either mode 1 or 2 instead of the mode 5 they usually chose...

[Rich Talbot-Watkins]

That screen would compress down to 30% I'm sure!

[tricky]

I did think that
Having loaded it, I would immediately have to hide it to load the game though.
Actually the 32K game (maze only exists in screen memory) currently compresses to about 12.5K, but loads at &4924.

[fwibbler]

Oh, I didn't realise the maze was done like that.
Damn Acorns stingyness with RAM!

[tricky]

What I did for Phoenix was to load the mode 7 splash screen and after 10 seconds load the mode 1 splash screen and keep swapping every 10 seconds and then*run the game when you press fire. That way, if you are in a hurry, you don't have to wait for the "loading" screen to load. Let me have a play once I sorry the ghosts out.

[tricky]

I've fixed a few bugs: dots not drawn correctly when ghosts reverse, pizza crust left when pacman dies and the siren sticking on when you complete a level while the ghosts are blue.
Known issues:
ghosts can get stuck in tunnel when changing back from blue.
you can still go through ghosts if timing is perfect.
fruit can't be collected and fruit starts on at beginning of level.
Half dots are still erased near junctions.
Energisers still have lines throught them for a short time after ghost has passed over them.
I'm sure that there are others that I am forgetting about!
1,420 bytes free, so still room for fixes and minor features.
There might be room for a 1/4 size version of that "loading" screen, I'll have a look.

[tricky]

Fixed two bugs in ghost speed, may still be a third.
Hopefully fixed moving through ghosts.

[tricky]

Got another hour, so fruit is now edible and fixed lines on energisers.

[FourthStone]

Wow! Have been following this thread keenly and really impressed at how great it looks and plays

Only bugs I noticed are the lines on the energisers when the red ghost reversed over one and the half dots around.

[tricky]

Thanks for testing. I thought that I had fixed the lines on the energisers when the ghosts go over them. Did you notice of they had just reversed direction? I thought that the reverse code was the same as the normal, but I've just remembered it is not, so that explains it.
You can still cause the line of you turn back at the last minute.
Still around 1.4K left.

PS The half dots are a pain to fix and will probably cost a couple of hundred bytes.

[Arcadian]

Wow, looks like a really solid release this, played through past 100k points (which was achieved relatively quickly now thanks to the addition of the fruit bonuses!).

No crashes, no pacman 'crusts', no pixels stuck in walls, no chunks of walls missing, no walking through regular ghosts/blue ghosts (even though I tried and tried and tried) and no ghosts getting stuck in the tunnel (despite powerpills expiring when ghosts were in the tunnel on a number of occasions).

I'd say the time spent this afternoon has really paid off! What aspect(s) are you going to look at next??

P.S. Have taken a screengrab of the 'key' FYI - which seems to transform into cherries halfway down

[tricky]

Thanks again for testing.

I'm open to suggestions for what is most important, but this is what I can think of off the top of my head and roughly the order I think that they need doing.

I need to add lives and game over.
The high score needs hooking up.
There are a couple of no entries to one way streets for ghosts that need implementing.
I want to fix the key.
There can be a dot hidden by a ghost when the player dies.
I want to display the fruit collected.

I would like to get Pacman's dying animation, but to align properly will take a lot of space.
It would be nice to get some sort of intermission animation with a tune.

The half dots are a pain to fix but would be nice to fix. (half fix for when dying added)

Pacman can still cause the lines in the energisers, as do reversing ghosts.

I would also like to get some better sound effects, but I don't know where from.

[tricky]

Out of order but, fixed "fruit" key and levels over 21 bug.
I'm not 100% that the ghosts are doing the correct thing

Added displaying lives - not in this .ssd though

As with my other games, you start with 4 and there are no extra lives, so it is very unlikely to become a marathon game.

You can also see where there should be a dot, up and left of pacman. This is the ghost hides a dot when pacman dies bug.

[tricky]

Fixed dots hidden by ghosts when Pacman dies (also tidies up 1/2 dots).
Only the first life is transferred to the maze, you still don't loose lives.

[tricky]

Added lives and high score, but game over just immediately restarts.
Also took the pause off eating fruit as it just didn't feel right.

[oss003]

Looks like the train is running tricky .....
Nice job .. keep up the good work.

Greetings
Kees

[tricky]

Unfortunately, the engine driver had to go and do other things, but he was back after he overslept!
Tidied up game over, the hi-score updates when you start the next game, so that you can see if you beat it.
RETURN or FIRE to start a new game.
I still haven't tested an of this new stuff on real HW
1,114 bytes remaining.

[tricky]

Added fruit collection display - will mess fruit display up after 16 fruits have been collected!
1078 bytes left.
All the remaining items are polish, I think the game play is now done, but please let me know of any bugs or missing features.

I would like to get Pacman's dying animation, but to align properly will take a lot of space (928 bytes just for gfx - cut down one would be ~400).
It would be nice to get some sort of intermission animation with a tune (guessing 200-300 bytes + tune).
The half dots are a pain to fix but would be nice to fix. (probable 200+ bytes)
Pacman can still cause the lines in the energisers, as do reversing ghosts (150+ bytes).
I would also like to get some better sound effects, but I don't know where from (? bytes).

[oss003]

Because the dying animation is relative slow, can't you do real time shifting for the dying sprites?

Greetings
Kees

[tricky]

Yes, of course, thanks.
Sometimes it's too easy to overlook the simple solution.
Ironically, I was writing a mode.4 version of Pacman back in the early 80s and everything was sixteen on the fly!