104 replies to this topic

[opcode]

Greeting programs!

Well, I resumed my Pac-Man Collection programming this week and here is a record of my activities so far:


UPDATE (May 10th):

- Ok, the gameplay is now starting to work out. I can't help but say it seems just... perfect. It amazes even myself. In the end I am hoping for 99.9% perfect gameplay.
- Pac-Man movement routines completed. It's a perfectly 3/4 scaled down version of the original Pac-Man movement. (check the new screenshots. BTW, if you look closely you will notice even that sprite bug from the original arcade. It still wasn't corrected in my sprite driver)


UPDATE (May 5th):

- Completed routines to deal with sprite attributes and animation.
- Created all sprite patterns. PMC will use two sets of sprites: a full sized pixel perfect set (the CV is such a nice machine with its perfect arcade resolution), which will be used with all intermissions and opening, and a 3/4 scalled down set, which will be used for the gameplay itelf. It's similar to Namco approach in Namco Museum, but I think I managed to produce a better looking set.
- Started work on preliminary sprite driver, which will be responsible for displaying sprite on screen in the desired scale, in adition to flickering things when necessary.

April 30:

- Finished all sound routines for Pac-Man and Ms Pac-Man. As usual routines are a direct port of the original arcade code, with the necessary changes required by CV sound hardware.
- Finished coding sound data for Pac-Man music and sound fx (but not for Ms Pac-Man yet). Again, sound data is a direct port of the original data. However here there is a key difference: the original Pac-Man hardware is capable of using wave samples, while the CV is just capable of square waves. Worst, some of those wave samples are fairly complex, so I was forced to make a lot of adjustments in frequency till I got the right sound for each FX.
- Overhall, I think Pac-Man has never sounded this good in a classic system. It's far better than Atarisoft's Pac-Man and slightly better than the MSX version of Pac-Man.

The following screenshot is old, but it shows the final maze for Pac-Man, including an inflated fruit counter.

Attached Thumbnails

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[Adrian M]

Wow. I've been very impressed with your CV ports of classic arcade titles thus far. I've never owned a CV, but you're making it more and more tempting with each new release!

[opcode]

Adrian M said:

Wow.  I've been very impressed with your CV ports of classic arcade titles thus far.  I've never owned a CV, but you're making it more and more tempting with each new release!  

Thanks!
The ColecoVision is a nice machine, with a lot of obscure (but very enjoyable) arcade ports.
About PMC, current plans are to have the Pac-Man portion of Pac-Man Collection playable in time to AGE 2.

[holygrailvideogames.com]

Please put me down for a pre-order. I can't wait to get this one. Your work is always great.

[Dav]

Very nice. Just curious, how are you handling the random number generation for pacman? Will you be able to duplicate the arcade version? I'm guessing you probably don't have an extra 8k to build a table. You could do it in a lot less if you rewrote the routine, though. But still, it would take a lot of space relatively.

[SS]

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

[holygrailvideogames.com]

SS said:

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

I bought my Colecovision because of the Space Invaders Collection as well. I still don't have that many games for the system, but hopefully I will change that in the future.

[Xot]

I forget, will this include Pac-Man Plus as well?

[Zaxxon]

mcgrail0007 said:

SS said:

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

I bought my Colecovision because of the Space Invaders Collection as well. I still don't have that many games for the system, but hopefully I will change that in the future.

I can't understand you Atari fans . How can you consider yourselves classic gamers and refuse to own a CV for 22 years? End the non-Atari system hate

[video game addict]

[Cootster]

Eh, I desperately want a CV (or its cheaper clones, do homebrews work on the DINA?), and, yeah the controllers are a tad lame, as are every second-generation control (What was this strange mutual keypad fetish? Why not something with a smaller footprint and more comfortable design?) . . .

And Pac-Man Collection looks awesome. Not too keen on SIC, just because it's not one of my favorite arcade games (Have the ROM, though, and it's probably the best port there is, although INV_ on the 2600 gives it a run for the money.

I want one for Lady Bug, and Pepper II, and the DK conversion that's even better than the one on Nintendo's own system, and Mindmaster w/o a Supercharger, and Zenji, and . . . There is just a very high cream-to-crap ratio with that system, it seems. Shame everybody and their dog making crappy games for the 2600 killed the market.

And another question: I was stoked about Magical Tree, and now it looks like I'll never be able to get it on a cart once I get a CV. Will the ROM be released since there are no plans to sell it?

[SS]

Cootster said:

Mindmaster w/o a Supercharger

That one was never officially released. It'd be nice to get a repro of it though.

[Zaxxon]

SS said:

Cootster said:

the DK conversion that's even better than the one on Nintendo's own system, and Mindmaster w/o a Supercharger, and Zenji, and . . .

That one was never officially released. It'd be nice to get a repro of it though.

Patience..

[opcode]

Dav said:

Very nice.  Just curious, how are you handling the random number generation for pacman?  Will you be able to duplicate the arcade version?  I'm guessing you probably don't have an extra 8k to build a table.  You could  do it in a lot less if you rewrote the routine, though.  But still, it would take a lot of space relatively.

Random number generator? I haven't found any random number generation routine so far. Anyway if it is there I am sure it doesn't need a 8k lookup table... Pac-Man original program is just 16KB (not including graphic roms), so there isn't space to such 8kb lookup table. And since I am more than 60 % done, I don't believe I will find any. If it is just a routine, well, I can't see why it wouldn't be reproduced.

mcgrail0007 said:

SS said:

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

I bought my Colecovision because of the Space Invaders Collection as well. I still don't have that many games for the system, but hopefully I will change that in the future.

Wow! Really?! I can't think of a better compliment and surely it will keep me motivated!

Xot said:

I forget, will this include Pac-Man Plus as well?

Hopefully it will....

Cootster said:

And another question:  I was stoked about Magical Tree, and now it looks like I'll never be able to get it on a cart once I get a CV.  Will the ROM be released since there are no plans to sell it?

The fun thing about Magical Tree is to have it as an exclusive game for contests, so the answer is probably not, I won't release the ROM. But there will be another chances to get a cartridge, including some which won't require any game skill.
Anyway I find it interesting the way people get crazy about something which they can't buy or own... :wink:

[Thomas Jentzsch]

So all ghosts follow a pattern (or rules) completely without any randomness?

[opcode]

Thomas Jentzsch said:

So all ghosts follow a pattern (or rules) completely without any randomness?

Yep, they follow rules. That's the nice thing about PM, each ghost has its own algorithm, though Pokey (the orange ghost, not that Atari sound chip) uses a lot of randomness. I will talk about it here later...

[SS]

opcode said:

mcgrail0007 said:

SS said:

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

I bought my Colecovision because of the Space Invaders Collection as well. I still don't have that many games for the system, but hopefully I will change that in the future.

Wow! Really?! I can't think of a better compliment and surely it will keep me motivated!

Really. I played the "Space Invaders Collection" at the PhillyClassic on Saturday. On Sunday I went home with a copy of it in one arm and a Colecivision to play it on in the other!

[Cootster]

SS said:

Cootster said:

Mindmaster w/o a Supercharger

That one was never officially released. It'd be nice to get a repro of it though.

Feh. I'd just build me one of those nifty link-cart devices like CPU showed off on here once. Expensive, but worth it, considering the amount of good protos the CV apparently has. . . Although I think Telegames made a lot of them on cart.

[Dav]

---------------random number generator------------------------
4dc9,4dca is the seed number out 4dc9 is new seed, a=rnd(0-ff)
2a23 2ac94d ld hl,(#4dc9) ;load seed number
2a26 54 ld d,h
2a27 5d ld e,l
2a28 29 add hl,hl
2a29 29 add hl,hl
2a2a 19 add hl,de
2a2b 23 inc hl ;hl=5 x seed +1
2a2c 7c ld a,h
2a2d e61f and #1f ;drop bits larger than $1fff
2a2f 67 ld h,a
2a30 7e ld a,(hl) ;read byte from 0 to $1fff
2a31 22c94d ld (#4dc9),hl ;store new seed number
2a34 c9 ret

The Roms are the lookup table. Many changes and the attract mode is different. The ghosts aren't random all the time just some of the time.

Dave

I can never remember how to keep the columns straight

[opcode]

You are absolutely right!
Well, this means I would need to include 8KB of code just to keep the gameplay intact. So be it....

[Nukey Shay]

Small price if it means that the gameplay will be more authentic

BTW Dave, you can [code] and [/code] your snips so that the text formatting remains unchanged.

[Dav]

It only uses the lowest 2 bits for direction, so I suppose you could chop it by 1/4 right off the top. It resets every level so you could probably cut that down. Or you could trap the significant attract mode reads. During the game no one will know the difference unless they run their pattern with a tolerance to match the frame rate. But as long as you have the space...


Thanks, Nukey I need to write that down.

Dave

[opcode]

I posted a few updates....

[Bruce Tomlin]

One instruction random number generator:

LD A,R

This is the refresh register used by the Z-80 for refreshing 16K DRAMs. On the ColecoVision, it's actually not used for anything (the DRAMs are controlled by the TMS9928), but it still counts up every clock cycle. Only seven bits of it change, and I never tried to see if the high bit is latched when loaded, or if it always stays off.

If you don't depend on it too much, and if varying user inputs cause varying cycle counts, it should be a decent source of randomness.

[holygrailvideogames.com]

Zaxxon said:

mcgrail0007 said:

SS said:

Adrian M said:

I've never owned a CV, but you're making it more and more tempting with each new release!  

The "Space Invaders Collection" is what pushed me over the edge into Colecovision ownership!

I bought my Colecovision because of the Space Invaders Collection as well. I still don't have that many games for the system, but hopefully I will change that in the future.

I can't understand you Atari fans . How can you consider yourselves classic gamers and refuse to own a CV for 22 years? End the non-Atari system hate

Actually I had one as a good. I bought one in 1982 with my brothers. All four of us put our money together and bought a system We have about 60 games. The only thing is that since we all bought this together it still remains at my parents house.

I have had other Colecovision since then, but they always broke. The one that I have now seems to be holding up so far. I had to find a working one so that I could play Space Invaders Collection.


Opcode,

If you need someone to test Pac-Man Collection on a real Colecovision after you are done, send me a private message. Pac-Man is still one of my all-time favorites.