Nice!

Btw, noticed a little bug that I'd not seen in any of the other versions.

I /think/ this was achieved by my bullet just/almost clipping the edge of the O ... ?

Thanks Dave, that is annoying! I thought that I had fixed that.

The targets are stored as left-X, mid-X, right-X, gap... and when I hit something i go right until i find a gap and then blank the three things to the left - this means that somewhere I have gone badly wrong.

Was it near to either end of the middle row when you clipped it as the ends of the middle row are a bit messy - I swap left-mid-right for right-mid-left as the are mirrored when travelling along the middle row.

Ah, I see.

Anyway, I'm pretty sure the point of [near] impact was the farthest-most O (on the right hand side) in the chain of O's. So fairly central-ish really?

I did find another bug that might cause "strange" things, usually a corrupt bonus box.

New image attached.

Happy new year and as a special treat, here are some dancing bears

EDIT: not as hypnotic as some of my demos, but still strangely compelling!

Here is a new disk image with bonus levels, there is still quite a bit to do, but the game-play should be complete now; barring difficulty tweaks.

Happy New Year to you too!

Well, you've managed to slot those bears in nicely - good work! I /think/ the increments in the bear's speed after each shot are slower/more gradual than in the arcade version, but (if I'm right) that's probably a good thing!

Best score so far is 24620 on level 6.

I did manage to crash the game once (on the third level) by firing a bullet at the music icon - but obviously you've not implemented toggle music on/off yet, so probably nothing to worry about at the moment.

One thing I've been meaning to raise for a while - can you double check the collision detection on bullets hitting the pipes? As sometimes I appear to hit them bang on yet they don't disappear.

I didn't check the speed of the bears, nor how they speed up, I just put in what felt like it might be ok and left it at that.

I keep feeling the collision on the left pipes when they are pointing up is a bit dodgy too, but only did a quick check of the code and couldn't see anything obvious - just had a thought, it might be from when I moved everything right by 4 pixels and didn't change the pip collision code - maybe that.

It is possible to miss a pipe on the right if the bullet goes up on the same frame that the pipe comes down - same with the falling ducks; these are also on the to do list.

Hitting the music toggle is probably a problem as it will assume you have hit a falling duck and that is unlikely - another issue from moving everything right (which was an optimisation for drawing the three rows of targets!)

I still have over 1/2 a KB left plus the 4 partial pages, so should have plenty of room left for the basics. Different sprite sets etc will have to be different "games" on the disk, as that saves code and data (the three rows of targets take nearly 2KB).

Off to try and beat your score now - will edit if I beat it

I've moved the music toggle box over so it doesn't crash the game and tweaked the duck generation code to make "camping" on the first level less attractive!

I'm on it ... !

Took a while, but finally reclaimed the hi-score

30480

EDIT - if only that last shot hadn't missed the [10]

Looks brilliant - a near-perfect conversion! I'd be inclined to put some colour interrupts in there, just so that every row has its own colours - not for authenticity, but just because you can, and it'd make the Beeb version look better than the original arcade version

You can also use all of page 3 (used only by the OS VDU code) and all of page 8 (used by the OS sound system). Blurp also uses some of the zero page for code, plus all of page 1 (minus 16 bytes reserved for stack), all of page 2 (apart from &204, &205 and &258), and all of page &D (apart from &D00 which is set to RTI). Hopefully that should give you a little more space to play with.

It also should make assembling the code a little more straightforward, as you can just assemble it in a big block from &100, with things like the IRQV pre-set (using SKIPTO &204 / EQUW myIrq in BeebAsm). Should save all the faff of having to copy bits of code all around the place. Another thing to consider is doing all your one-time initialisation before relocating the code down, which should save clogging up memory with code that's only executed once at startup.

Seriously excellent work there, most impressed!

Thanks Rich, helpful as ever.

I was planning on looking through the other OS's to check what was actually used once I unpacked my old EPROMs, but you just saved me some searching.

My first reaction was that I don't have any one time code, but of course I do, the relocation code is already dumped, but the interrupt setup code isn't - because it is with the mode setup, but that can easily be fixed.

I will also need to add some hi-score display, keyboard remapping and probably some other intro code and that can all be disposable if I do it in mode 7 - a much better use for the space than the sampled audio I was planning.

Added the font and labels (don't know why Z is the only letter that is 5 pixels wide!).
Added explosions, but haven't checked if I have the correct explosions for everything - bears should have 1 frame of red (blood spatter!), but I didn't put it in.
Reworked pipes (and non-pipes) collision (it was broken on left), so prepare for all new bugs.
The font went into the second half of page 2 and all of page 3 - thanks RichTW, but I seem to have misplaced a page somewhere, probably due to re-working the relocation code to give me a bit more space!

New .ssd attached

I'm on it

Wow, you've managed to cram a lot of frames into each explosion. Impressed!

Heh, is that for 'compassionate' reasons (as opposed to memory restrictions etc). If the former, then I'm with you on that!

Also, the last thing we want is the game getting a PEGI 18 rating due to animal cruelty!

Well, pipe collision on the right(!) has definitely improved too - in fact it seems perfect now.

Only had a few goes (at it's rather late, LOL) but I've not spotted any new bugs. Though bullets still occasionally leave a trace behind: something that seems to affect the bonus stages in particular.

I've seen bullets left on the gun row of the bonus stage (they shouldn't even be drawn their). I will check all the bullet routines next. Later than me

Just had a quick play of latest update.

The game keeps looking better. Very smooth. I like RTW's different colour on each row idea.. would really make the game stand out.

Tricky, hope you can squeeze in a high score table and also joystick control. This would make the game a surefire hit at Retro computer meet ups!

Just this minute finished adding the hi-score table, although you will need a hex editor to read it at the moment, although it should be sorted and rank should work. I haven't tried the save/load of HISCORE yet, but it is written.
Still have a bug with hitting pipes and have managed to leave a bullet on the edge of a falling duck.
I've stuck the HISCORE in the the stack page, and am into my last page now.
I have only used 32 bytes of zero page and some of that was for sfx which I haven't added yet.
I think with a big tidy up, I could have two pages (1/2 KB) total memory left, so things are really getting very tight now - I should really be adding things in priority order as it is looking more and more like I am going to run out of space and I really don't want to take stuff out again.
I will post a new image tomorrow sometime after I have had a chance to check HISCORE load/save and maybe fixed a couple of bugs.