WIP: Bubble Bobble

[scalz8]

Hey there! I'm not exactly a pro developer, more of a VIC20 enthusiast. For years, I've harbored a dream: to see a VIC20 rendition of Bubble Bobble. We've chatted about it for ages, but sadly, no progress has been made, except for another user who crafted a demo with the Bubble Bobble soundtrack and a moving Bub.

So, just to spark some interest in this dream, I've whipped up a super simple demo, using only the most basic RAM requirements. Only Bub and a monster falling down And get this, it's all in BASIC! Yeah, I know, it sounds a bit old-school, but there's something special about revisiting my VIC20 programming days from childhood. <3

Feel free to check out the demo, borrow character ideas, heck, do whatever you like with it! If it inspires any talented developers out there to create a basic version of Bubble Bobble—even just a 10-level version with limited features, objects, and a couple of monsters—that would be amazing! Let's make this dream a reality!

BubSprites220125.d64.zip

(1.77 KiB) Downloaded 25 times

[Mike]

Hi, scalz8!

First of all, welcome to Denial!

I just made a quick peek at your WIP or demonstrator. For ease of discussion, here's the program text:

Code: Select all

10 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT
11 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT
100 POKE36869,255
103 POKE36878,20
105 POKE36879,13
110 FORI=7168TO7679:POKEI,PEEK(I+25600):NEXT
130 FORI=7168TO7247
140 READA:POKEI,A:NEXT
142 REM***SCREEN***
143 FORM=0TO22:POKE7680+M,8:POKE38400+M,10:NEXTM
144 FORM=0TO22:POKE8164+M,8:POKE38884+M,10:NEXTM
145 FORM=0TO21:POKE7702+M*22,8:POKE38422+M*22,10:NEXTM
146 FORM=0TO21:POKE7723+M*22,8:POKE38443+M*22,10:NEXTM
147 POKE8116,9:POKE38836,15:POKE7770,9:POKE38490,15
148 FORI=0TO1:FORM=0TO4:POKE7834+154*I+M,8:POKE7842+154*I+M,8:POKE7851+M+154*I,8
149 POKE38554+154*I+M,10:POKE38562+M+154*I,10:POKE38571+154*I+M,10:NEXTM:NEXTI
151 REM***DRAGHETTO***
153 X=7685:C=30720
154 Y=7694:D=30720
155 POKEX,0:POKEX+C,15:POKEX+1,1:POKEX+C+1,15
156 POKEX+22,2:POKEX+22+C,15:POKEX+1+22,3:POKEX+22+C+1,15
157 FORT=1TO2:NEXT:POKEX,32:POKEX+1,32
158 POKEX+22,32:POKEX+22+1,32
159 X=X+22:IFX>8185THENX=7685:C=30720
160 FORT=1TO100:NEXT
165 REM***MOV.MOSTRO***
167 POKEY,4:POKEY+D,10:POKEY+1,5:POKEY+D+1,10
168 POKEY+22,6:POKEY+22+D,10:POKEY+1+22,7:POKEY+22+D+1,10
169 FORT=1TO2:NEXT:POKEY,32:POKEY+1,32
170 POKEY+22,32:POKEY+22+1,32
171 Y=Y+22:IFY>8185THENY=7694:D=30720
172 FORT=1TO100:NEXTT:GOTO155
188 DATA2,34,37,37,151,151,27,155,0,128,80,220,48,48,48,48
189 DATA149,20,41,41,35,199,214,154,84,48,84,240,252,252,252,186
190 REM*** MOSTRO ***
191 DATA15,63,63,63,51,51,51,63,252,255,251,226,34,59,62,248
192 DATA63,0,42,42,58,62,12,0,254,42,170,170,168,176,48,252
195 REM***TILE&BANANA***
196 DATA151,93,117,214,90,105,165,150,10,3,2,14,10,43,172,240
900 POKE36869,240

This is for unexpanded VIC-20.

Some remarks:

• When using UDGs (user defined graphics) in BASIC, you need to make sure that the BASIC interpreter cannot overwrite your UDGs or, vice versa, the UDGs overwrite vital data/variables of your BASIC programs. Usually, either the top of available memory is lowered (with POKE55,...:POKE56,...:CLR) or the BASIC start is raised (that's a bit more complicated but covered in some other threads here in Denial).
• It is not necessary to make a full copy of the character set in line 110. At the moment, you do not use the standard character set at all, but even if so, you already have access to the non-inverse characters of the original character set by printing them in inverse. This is due to an address wrap-around of the video chip, and this is a technique that was well established already in contemporary computer magazines.
• The shapes are displayed for a comparatively short amount of time only, leading to noticable flicker. If you change the order of the corresponding POKEs, that flicker is much reduced:

Change lines 155..159 and 167..171 as follows (omitting the loop "FORT=1TO2:NEXT"!):

Code: Select all

155 POKEX,32:POKEX+1,32
156 POKEX+22,32:POKEX+22+1,32
157 X=X+22:IFX>8185THENX=7685:C=30720
158 POKEX,0:POKEX+C,15:POKEX+1,1:POKEX+C+1,15
159 POKEX+22,2:POKEX+22+C,15:POKEX+1+22,3:POKEX+22+C+1,15

167 POKEY,32:POKEY+1,32
168 POKEY+22,32:POKEY+22+1,32
169 Y=Y+22:IFY>8185THENY=7694:D=30720
170 POKEY,4:POKEY+D,10:POKEY+1,5:POKEY+D+1,10
171 POKEY+22,6:POKEY+22+D,10:POKEY+1+22,7:POKEY+22+D+1,10

... and you see the difference.

[pixel]

Nah. It's impossible to achieve on the VIC. Looking good though.

[beamrider]

Chat GPT says it's possible

Creating a version of Bubble Bobble for the VIC-20 is an exciting project! The VIC-20 is a classic home computer that runs on the 6502 microprocessor. Developing a game like Bubble Bobble on this platform involves several key aspects: understanding the limitations of the VIC-20, programming in 6502 assembly language, and designing game mechanics and graphics suitable for the hardware.

Key Considerations:
Memory Constraints: The VIC-20 comes with 5 KB of RAM by default, which can be expanded, but games need to be designed to run within this limited memory if you aim for broad compatibility.
Graphics and Sound: The VIC-20's graphics capabilities are modest, with a 22x23 character display and a 16-color palette. Its sound capabilities are also limited compared to more modern systems.
Programming Language: You'll need to program in 6502 assembly language, which is the native language for the VIC-20's microprocessor.
Steps to Create the Game:
Game Design:
Simplify the game mechanics of Bubble Bobble to fit the VIC-20's capabilities.
Plan the level design, character movement, and scoring system.
Graphics Design:
Design sprites within the limitations of the VIC-20. Each sprite typically occupies a single character cell.
Use the VIC-20's color palette effectively to make the game visually appealing.
Sound Design:
Compose simple sound effects and possibly a background tune using the VIC-20's three voice sound synthesizer.
Programming:
Start by setting up a development environment that includes an emulator and a 6502 assembler.
Write the core game loop, input handling, collision detection, and game logic.
Optimize memory usage to ensure the game runs smoothly on the VIC-20's limited hardware.
Testing and Optimization:
Test the game thoroughly on an emulator and ideally on actual VIC-20 hardware.
Optimize code and graphics to improve performance and reduce memory usage.
Distribution:
Once the game is complete and thoroughly tested, consider how you will distribute it. Options include making it available as a ROM file for emulators, or even producing physical cartridges for enthusiasts.
Tools and Resources:
VICE Emulator: A popular emulator that can simulate a VIC-20 and help with testing.
CBM prg Studio or Kick Assembler: Software for developing and compiling 6502 assembly code.
Online Communities: Forums and online communities can provide support and advice from experienced VIC-20 developers.
Developing a game like Bubble Bobble for the VIC-20 is a challenging but rewarding project that requires a deep understanding of both game design and low-level programming. It's a great way to delve into vintage computing and game development!

[majikeyric]

[pixel]

Chat GPT says it's possible

Yes. If you play it through. chatGPT, I mean.

[scalz8]

Next version chatGPT will reply like this: “Yes, it is possible but
not needed, since smart guys in the Denial community already did that. The vic20 porting of Bubble Bobble became a milestone of retroprogramming fans after Doom, Popeye and Prince of Persia. Or the new generation games such as Cheesy Trials, Cheese and Onion, and many others available on line on the third millennium. ” !!!!!

PS: maybe calling it Cheesy Bubble would be a way to trigger the attention of the most … famous … coders in this community

Chat GPT says it's possible

Creating a version of Bubble Bobble for the VIC-20 is an exciting project! The VIC-20 is a classic home computer that runs on the 6502 microprocessor. Developing a game like Bubble Bobble on this platform involves several key aspects: understanding the limitations of the VIC-20, programming in 6502 assembly language, and designing game mechanics and graphics suitable for the hardware.

Key Considerations:
Memory Constraints: The VIC-20 comes with 5 KB of RAM by default, which can be expanded, but games need to be designed to run within this limited memory if you aim for broad compatibility.
Graphics and Sound: The VIC-20's graphics capabilities are modest, with a 22x23 character display and a 16-color palette. Its sound capabilities are also limited compared to more modern systems.
Programming Language: You'll need to program in 6502 assembly language, which is the native language for the VIC-20's microprocessor.
Steps to Create the Game:
Game Design:
Simplify the game mechanics of Bubble Bobble to fit the VIC-20's capabilities.
Plan the level design, character movement, and scoring system.
Graphics Design:
Design sprites within the limitations of the VIC-20. Each sprite typically occupies a single character cell.
Use the VIC-20's color palette effectively to make the game visually appealing.
Sound Design:
Compose simple sound effects and possibly a background tune using the VIC-20's three voice sound synthesizer.
Programming:
Start by setting up a development environment that includes an emulator and a 6502 assembler.
Write the core game loop, input handling, collision detection, and game logic.
Optimize memory usage to ensure the game runs smoothly on the VIC-20's limited hardware.
Testing and Optimization:
Test the game thoroughly on an emulator and ideally on actual VIC-20 hardware.
Optimize code and graphics to improve performance and reduce memory usage.
Distribution:
Once the game is complete and thoroughly tested, consider how you will distribute it. Options include making it available as a ROM file for emulators, or even producing physical cartridges for enthusiasts.
Tools and Resources:
VICE Emulator: A popular emulator that can simulate a VIC-20 and help with testing.
CBM prg Studio or Kick Assembler: Software for developing and compiling 6502 assembly code.
Online Communities: Forums and online communities can provide support and advice from experienced VIC-20 developers.
Developing a game like Bubble Bobble for the VIC-20 is a challenging but rewarding project that requires a deep understanding of both game design and low-level programming. It's a great way to delve into vintage computing and game development!

[scalz8]

Thank you Mike for your greetings and your kind explanation on your decision to move the post. I was in doubt on where to position the post, indeed. So, thanks for your understanding on my mistake.
I can’t wait to try to change those lines!
Like when I was a child typing by hand those looooooong codes from vic20 magazines
Thanks also about your info about the character set, which I was used to notice when I was a kid, indeed, but never know it was intentional.
About poke56 clear, instead, what am I supposed to do? Just to type that command at first?

Thanks and bye!

Hi, scalz8!

First of all, welcome to Denial!

I just made a quick peek at your WIP or demonstrator. For ease of discussion, here's the program text:

Code: Select all

10 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT
11 PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT:PRINT
100 POKE36869,255
103 POKE36878,20
105 POKE36879,13
110 FORI=7168TO7679:POKEI,PEEK(I+25600):NEXT
130 FORI=7168TO7247
140 READA:POKEI,A:NEXT
142 REM***SCREEN***
143 FORM=0TO22:POKE7680+M,8:POKE38400+M,10:NEXTM
144 FORM=0TO22:POKE8164+M,8:POKE38884+M,10:NEXTM
145 FORM=0TO21:POKE7702+M*22,8:POKE38422+M*22,10:NEXTM
146 FORM=0TO21:POKE7723+M*22,8:POKE38443+M*22,10:NEXTM
147 POKE8116,9:POKE38836,15:POKE7770,9:POKE38490,15
148 FORI=0TO1:FORM=0TO4:POKE7834+154*I+M,8:POKE7842+154*I+M,8:POKE7851+M+154*I,8
149 POKE38554+154*I+M,10:POKE38562+M+154*I,10:POKE38571+154*I+M,10:NEXTM:NEXTI
151 REM***DRAGHETTO***
153 X=7685:C=30720
154 Y=7694:D=30720
155 POKEX,0:POKEX+C,15:POKEX+1,1:POKEX+C+1,15
156 POKEX+22,2:POKEX+22+C,15:POKEX+1+22,3:POKEX+22+C+1,15
157 FORT=1TO2:NEXT:POKEX,32:POKEX+1,32
158 POKEX+22,32:POKEX+22+1,32
159 X=X+22:IFX>8185THENX=7685:C=30720
160 FORT=1TO100:NEXT
165 REM***MOV.MOSTRO***
167 POKEY,4:POKEY+D,10:POKEY+1,5:POKEY+D+1,10
168 POKEY+22,6:POKEY+22+D,10:POKEY+1+22,7:POKEY+22+D+1,10
169 FORT=1TO2:NEXT:POKEY,32:POKEY+1,32
170 POKEY+22,32:POKEY+22+1,32
171 Y=Y+22:IFY>8185THENY=7694:D=30720
172 FORT=1TO100:NEXTT:GOTO155
188 DATA2,34,37,37,151,151,27,155,0,128,80,220,48,48,48,48
189 DATA149,20,41,41,35,199,214,154,84,48,84,240,252,252,252,186
190 REM*** MOSTRO ***
191 DATA15,63,63,63,51,51,51,63,252,255,251,226,34,59,62,248
192 DATA63,0,42,42,58,62,12,0,254,42,170,170,168,176,48,252
195 REM***TILE&BANANA***
196 DATA151,93,117,214,90,105,165,150,10,3,2,14,10,43,172,240
900 POKE36869,240

This is for unexpanded VIC-20.

Some remarks:

• When using UDGs (user defined graphics) in BASIC, you need to make sure that the BASIC interpreter cannot overwrite your UDGs or, vice versa, the UDGs overwrite vital data/variables of your BASIC programs. Usually, either the top of available memory is lowered (with POKE55,...:POKE56,...:CLR) or the BASIC start is raised (that's a bit more complicated but covered in some other threads here in Denial).
• It is not necessary to make a full copy of the character set in line 110. At the moment, you do not use the standard character set at all, but even if so, you already have access to the non-inverse characters of the original character set by printing them in inverse. This is due to an address wrap-around of the video chip, and this is a technique that was well established already in contemporary computer magazines.
• The shapes are displayed for a comparatively short amount of time only, leading to noticable flicker. If you change the order of the corresponding POKEs, that flicker is much reduced:

Change lines 155..159 and 167..171 as follows (omitting the loop "FORT=1TO2:NEXT"!):

Code: Select all

155 POKEX,32:POKEX+1,32
156 POKEX+22,32:POKEX+22+1,32
157 X=X+22:IFX>8185THENX=7685:C=30720
158 POKEX,0:POKEX+C,15:POKEX+1,1:POKEX+C+1,15
159 POKEX+22,2:POKEX+22+C,15:POKEX+1+22,3:POKEX+22+C+1,15

167 POKEY,32:POKEY+1,32
168 POKEY+22,32:POKEY+22+1,32
169 Y=Y+22:IFY>8185THENY=7694:D=30720
170 POKEY,4:POKEY+D,10:POKEY+1,5:POKEY+D+1,10
171 POKEY+22,6:POKEY+22+D,10:POKEY+1+22,7:POKEY+22+D+1,10

... and you see the difference.

[MrSterlingBS]

Hi @ all,

I am very interested in implementing Bubble Bobble on the VIC. How can I support?

BR
Sven

[scalz8]

Hello Sven.
I think the best way is to use something like “Turbo Rascal” environment platform. But I tried and honestly didn’t manage to make it working for my Vic20

[pixel]

Kay. How about you write a tiny 6502 assembler with Turbo Rascal and then ask again who wants to invest months in a game for nothing in return.

[Mike]

[...] who wants to invest months in a game for nothing in return[?]

It is somewhat unfair to come up with this argument to someone who first of all just asked about a possible port of BB to the VIC-20. One still finds companies that sell commercial game software for the VIC-20, so there must be a market for it. If one writes a game for the VIC-20, and asks nothing for it, it is a hobbyist project. With perhaps a chance to obtain a good ranking in the Oldskool Games Compo on Revision (see here ).

There is also the matter with ports of games still in copyright versus implementations of own/new game ideas. In the former case, there is always the licence issue. The original design of the Bubble Bobble arcade was done by Taito - it is not especially funny to obtain a licence when the game idea/mechanic still is actively marketed (there exist ports of BB on current game consoles, for example).

scalz8 - it always possible to put an inquiry of that kind here, and maybe that inquiry even strikes a chord with someone (like what happened with me with Mah Jongg years ago), but you can't count on that and then the second best outcome is to equip yourself with the necessary knowledge (and for this, you will find lots of examples here in Denial!) to do it yourself. That is pretty much the same situation you are now in as another poster who just recently asked about ELITE to be ported.

I'd recommend you to re-acquire yourself with the VIC-20 and its technical capabilities. The handling of user defined characters is discussed in roughly every 10th topic in the Programming section here in Denial, so you should refer to those. Alternatively, take a look at other people's programs/games how they handle things. For a starter, check out my Games Collection for the unexpanded VIC-20 from 2013. It mostly contains contemporary type-ins and these should give you a good idea how to do animation in games and concurrent movement of two or more objects, combined with joystick control, score display, sound and what not.

[bjonte]

The screenshot looks nice! This would be a very challenging project though. It kind of requires double buffering and it’s not the VIC’s strength because of the limited graphics memory.

[pixel]

[...] who wants to invest months in a game for nothing in return[?]

It is somewhat unfair to come up with this argument to someone who first of all just asked about a possible port of BB

You're right. I'm overly pessimistic. Perhaps make it a group effort. I'd love to see it, too.

I'd start out with cc65 as a skeleton and doing the boring stuff like saying hello or disk I/O. A working and rather fast sprite engine with variable dimensions is also there and the game logic, call me crazy, could be done in C. The problem is that megaton of sprites. No double buffer required.

[scalz8]

[...] who wants to invest months in a game for nothing in return[?]

It is somewhat unfair to come up with this argument to someone who first of all just asked about a possible port of BB to the VIC-20. One still finds companies that sell commercial game software for the VIC-20, so there must be a market for it. If one writes a game for the VIC-20, and asks nothing for it, it is a hobbyist project. With perhaps a chance to obtain a good ranking in the Oldskool Games Compo on Revision (see here ).

There is also the matter with ports of games still in copyright versus implementations of own/new game ideas. In the former case, there is always the licence issue. The original design of the Bubble Bobble arcade was done by Taito - it is not especially funny to obtain a licence when the game idea/mechanic still is actively marketed (there exist ports of BB on current game consoles, for example).

scalz8 - it always possible to put an inquiry of that kind here, and maybe that inquiry even strikes a chord with someone (like what happened with me with Mah Jongg years ago), but you can't count on that and then the second best outcome is to equip yourself with the necessary knowledge (and for this, you will find lots of examples here in Denial!) to do it yourself. That is pretty much the same situation you are now in as another poster who just recently asked about ELITE to be ported.

I'd recommend you to re-acquire yourself with the VIC-20 and its technical capabilities. The handling of user defined characters is discussed in roughly every 10th topic in the Programming section here in Denial, so you should refer to those. Alternatively, take a look at other people's programs/games how they handle things. For a starter, check out my Games Collection for the unexpanded VIC-20 from 2013. It mostly contains contemporary type-ins and these should give you a good idea how to do animation in games and concurrent movement of two or more objects, combined with joystick control, score display, sound and what not.

Thanks Mike for your comments. Anyway, never say never.... I haven't got your skills, but in the future.. I'll try to trigger the interest of this community, who knows, by some other demos

Hewco UK, who for sure is reading this now .... also made a nice video with the soundtrack, few years ago.

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

Also, there was an interesting port for the Game Gear, with simplified levels which could inspire additionally someone
https://www.youtube.com/watch?v=dMDLhdNnI6k