Ghostbusters (Activision)

[ChrisB]

Sometimes things take longer than you expect - and sometimes things "just work". As such I've added the driving section into the game flow. This includes speed up, slow down and different speed cars - although you can't change which car you have currently.

The ghosts on the car screen are still just decoration - the next job is to make them appear at appropriate times - and to allow them to be vacuumed up.

I'm not convinced about the colours yet and might try a different variation next release. There's also occasional corruption on the driving screen that I need to fix. It's also quite obvious that your rate of earnings is far to low to complete the game so there needs to be rebalancing here. 2.5K free.

gb.ssd

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[ChrisB]

This release changes the colours - I think I like these better. Comments welcome. The ghosts also appear according to how far along the drive path you are when you cross them. Pressing Action (L) will vacuum them up if they are over the car - no animation for this they simply disappear - but they are reset back to the corners of the map so this gameplay "works". Internally - because there are very few 1 bit sprites - I've removed the reversed plot routine and inserted mirrored sprites instead. I've also added more frames for the Marshmallow man. I believe that overall this saves some memory and simplifies the plot code - although it's close. I'm probably going to look at updating the 1bit plot code to allow sprites to appear/disappear at the top/bottom of the screen. Other items on the list:

Marshmallow man logic.
Shop/Intro screens.
Final screen(s).
Various character animations.

gb.ssd

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2.3K free.

[Dave_E]

It's really superb now. Feels like it's very near completion too. I love the way you've incorporated the road 'speed up' and 'slow down' effects at the start and end of the journey. I thought of a few questions:

1. Are you planning to put in the 'bouncing song lyrics' at the beginning?
2. Are you planning to recreate the 'unique account number' (combined with account name) that allows 'save progress' to work on every other version?

It's so great having this game on the Beeb finally. I can't wait to see the finished version.

[ChrisB]

There's still quite a bit of game logic to go at the moment. I am slightly concerned with space - we'll see how it goes.

1. Are you planning to put in the 'bouncing song lyrics' at the beginning?
Yes - but this is going to be one of the last things to do.
2. Are you planning to recreate the 'unique account number' (combined with account name) that allows 'save progress' to work on every other version?
Yes - I have the algorithm from elsewhere. The whole "shop" experience needs to be added. All the text and graphics is already included in the build but there's a decent amount of logic to write. I'm intending to run it in mode 1 so there needs to be a new plot routine (or possibly I can re-use/modify the current one - not sure.).

[fwibbler]

Yep, this is looking and playing nicely.

Just a couple of things,
Will the cards travel at different speeds ?
When I first enter the map screen, the player symbol moves about twice as fast as normal. After travelling somewhere it moves at the normal speed thereafter.
When you go back to GHQ will you add the men running out to the car?

Cheers!

[ChrisB]

Will the cards travel at different speeds ?
Yes - This is already in but you have no means to select the car as yet. That's the reason it defaults to the "sports" car to move around the map faster.

When I first enter the map screen, the player symbol moves about twice as fast as normal. After travelling somewhere it moves at the normal speed thereafter.
That's not something I seem able to reproduce here. What environment are you running under?

When you go back to GHQ will you add the men running out to the car?
Yes - The animations like this (And things like taking a full trap back to the car after capturing a ghost) are intended to be in. The status scroll on GBHQ is just there to force a pause at that point at the moment.

[ChrisB]

Time for another update. I've started adding the shop screens. At the moment the first text screens are fixed - no account details entry. However you can show the car options with Space and choose the car types with 1-4 (No currency restriction at the moment). The car chosen will be used in the main game. These screens are mode 1 (as opposed to mode 2 in the game) and I've used the OS text plotting routines for the text to save space. I've also modified the sprite plot routines to allow the same routine to be used for Mode 1 and 2.
Lastly the ghosts on the driving screen have been updated to allow them to clip to the top and bottom to make them appear gradually.

gb.ssd

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1.9K free.

[fwibbler]

Will the cards travel at different speeds ?
Yes - This is already in but you have no means to select the car as yet. That's the reason it defaults to the "sports" car to move around the map faster.

When I first enter the map screen, the player symbol moves about twice as fast as normal. After travelling somewhere it moves at the normal speed thereafter.
That's not something I seem able to reproduce here. What environment are you running under?

Finally got round to making a short video of this happening:
I'm using Beebem 4.17 on Windows 7.

[ChrisB]

Finally got round to making a short video of this happening:

Thanks for that - Further investigation shows it happening on a model B under emulation bit not the BPlus. As such it's probably just an uninitialised counter. I'll have to check that logic.

Anyhow - time for another update. This version allows you to enter an account number and have this affect your starting balance. The cars also have a cost associated with them so you'll need an account number to afford the "High Performance" car. I'd suggest "MICRO,BBC" and account 40606300 for $32000. Account numbers are broadly compatible with the C64 version. I've restricted account names to being textual only (for input validation simplicity) and the account number to exactly 8 digits so any "proper" numbers from the c64 version should work but some of the "cheat" codes out there won't. Comments on the restriction welcome. The code for generating the account number when you win is also present - but not used.

I've also updates the text plot to appear gradually - but faster than the C64 version which took an age to write the first screen.

Currently looking at the most efficient way to do the equipment screens so I think they will be next. Still slightly concerned about the amount of free space but I have some ideas around this.

gb.ssd

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1.6K free.

[ChrisB]

Now with shopping.

This version adds the equipment buying part of the game. As always this is not exactly the same as another version but I'm quite happy with it. All the functionality should be present with equipment slot limits per vehicle and cash reduced as you purchase items. As far as I can tell in the original there doesn't seem to be a way to "undo" a purchase and you can quite easily get to an invalid loadout without a way back. I've not "corrected" this.

Note that the only item that affects gameplay at the moment is the number of traps you have purchased. All the other equipment is just cosmetic for now.

gb.ssd

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The shop code took more space that I expected and I currently have 959 bytes free. Things left to do include:

• Add Keymaster/Gatekeeper to the map screen
• Add marshmallow attack
• Add "final" screen
• Add remaining game logic including game end
• Add animations
• Add the limited sound effects
• Finalise house colours

Of the above the end screen is the most problematic. The CPC uses a normal house screen for the end section where you have to avoid the marshmallow man and doesn't have a "final" screen. I might have to go down this route (although I'll try my best not to). I was always intending to produce a version with sampled speech but this was going to be sideways ram only. If I can't fit these extra screens into the "base" game they will be included in that version.

[Rob_hawk]

Another great update as the year comes to an end Chris. It will be just superb if the there’s a sideways RAM version with the sampled speech as well! Good luck with fitting the ending in!!

[ChrisB]

Watch out - there's marshmallows about! This version adds the marshmallow attack. At the moment this occurs much earlier on in the game than it would normally for testing purposes (first one will be just after 1300 PK energy). Press B as the ghosts are gathering to divert them to your location. No check is made for how much bait you have so this will work every time. If you don't press B in time then the building will be destroyed.

As part of this routine I've changed the ghost movement to use the generic goto. This also allows you to lay bait when there isn't a marshmallow man on screen - and the ghosts will go there and cluster round the bait.

I also noticed that I was overcomplicating the ghost movement and allowing it to happen when the map screen wasn't displayed. Going back to the c64 version I see this doesn't happen and the ghosts remain in place as you move to the other screens. Therefore this movement has been moved into the map screen - saving a few bytes.

Lastly I've tidied up the clearscreen to set the palette to blue to hide the drawing routines.

gb.ssd

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443 bytes free. Which brings me to a couple of tough decisions. There's almost no way that I'm going to be able to fit the remaining logic in at the moment on a standard beeb. There are some space savings to be made - but not that much that I can see. As such I'm probably gonig to have to drop some features if I want to produce a version that can run there (which I would still like to do). Th SW RAM version is still on the cards as an extended version and this should retain all the original features.

My thought at the moment is that the keymaster/gatekeeper sprites add very little here. Te sprites themselves are small (<32 bytes) but there's a whole piece of navigation logic to get them round the city and to the Zull building that adds almost nothing to the gameplay. I'm thinking that simply recolouring the Zull building when it's about to be active then flashing red when you need to go there.

I've also mentioned the ending scene prevously as problematic so this isn't likely to be on the standard version (as per the CPC). Lastly the cars that sit outside the capture building are merely decoration. Rather than remove them completely I'm looking to keep one of the cars which should give around another 200 bytes.

Does anyone have any thoughts or comments on the above?

[nicolagiacobbe]

Thanks Chris, it is getting better every time and the memory is disappearing fast too. Hope you'll reach the end with al least a few bytes to spare.

[Rob_hawk]

Hi Chris, Thanks for the next update. I think it will just be great to be honest to have a version of this for the unexpanded Model B that has most of the functionality and then an enhanced version for SWRAM models that has all the bells and whistles, especially the speech! I think I remember saying that a high percentage of people had some SWRAM and in any case I think both versions will be very well received

Cheers

Rob

[ChrisB]

Testing required for the grand finale.

I've implemented the "final" screen for the normal BBC version. This version jumps directly to this after the equipment purchase. Dodge the marshmallow man and enter the open door (just to the right of the lefthand door). Get two men through to "win". Please let me know what you think.

It is possible to see all three endings.

• Fail to get two men through to lose
• Buy a low value car and a single trap to have more money that you started with and win
• Buy a high value car and/or lots of equipment to win but have the bank foreclose

gb.ssd

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About 170 bytes free. I need to add logic to get to the endgame, fix a corruption that happens on the driving screen, make the equipment actually do something and add the animations. Bit tight still!

[Cybershark]

Tested!

Wow, it's a pretty tight window to get your guys through the door... Only seemed to manage it 50% of the time. Out of curiousity, what happens if you only have one guy remaining when you get to that point? Are you congratulated if you only have one fella left?

Did you say you'd done the account code system? I tried using one from a winning game (and was sure I had it right) but it was rejected.

[ChrisB]

At the moment you are assumed to arrive with three men (Even if you've lost some during the game - the final showdown reenergises the ghostbusters... something something ... movies etc.) Didn't seem fair to force the player to go back to GBHQ when the game will prompt you to go to zuul. However if you only manage to get one man through then you will lose the game. Don't know whether to end the game when you lose 2 men though. Would allow the player to practice for next time. Thoughts?

Regarding the account number - yes that should work - and it works for me. Remember that you need to enter your name last<comma>first - it's displayed as first<space>last on the end screen. You don't have to enter two names so a single name might be easier to test with.

[lovebug]

great

[ChrisB]

Feature complete?

Two versions today. This release brings the last piece of gameplay logic in. As the endgame approaches the Zuul building will turn pink indicating that Zuul is nearly here. Shortly after this the building will go red and flash. Go to the building to start the end game. The win/lose conditions have also been updated - The final balance is now checked BEFORE the final showdown - rather than after meaning you need to make your starting money back before the winning $5000 bonus.
There are two versions here - version a triggers the endgame after about 3000 PK energy for testing. It's perfectly possible to win with a frugal build - Version B more at the intended range of 8000+ also allowing the marshmallow man to appear.
Other changes are as follows:

• The marshmallow man only visits once a successful ghost capture has been performed
• Equipment is now required to perform it's functions.
• Image intensifier routine implemented. The capture ghost is less visible without. I'm thinking of making this less visible - feedback appreciated.
• Doubled the speed of the ghosts on the driving screen
• Parked car for capture and finale removed for memory purposes
• Moved the loader down to &1200 to allow space for later
• Reordered the equipment screens to make code elsewhere easier

This is very close to it's final look and feel (At least for the 32K version) and I would really appreciate how people thing it feels/plays. Is the difficulty/balance right?

gb_a.ssd

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gb_b.ssd

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115 bytes free - I will need to look at what I can do here as the things to do list is a little long.
Things to do:

• Fix the action button not working well on the capture screen
• Make he ghost leave if the capture times out
• Fix the screen corruption on the driving screen
• Incidental sounds
• As much animation as I can fit in (gb exit, ghost capture whilst driving, and the capture screen animations.)
• Updated loader screen with key redefinitions, song lyrics etc.

After that I'll look to create a sideways RAM version with any remaining animations, sampled sound and an extended finale with additional graphics.

[fizgog]

Congrats Chris on getting it this far, I envy your skill and determination.

I'm still working long hours at work as our deadline has been moved to Feb1, but with a lot more features added, so have not been able to even look at any of my own code.

I've downloaded both files and will try and find some time tonight to give it a quick test, even though I'm not a big fan of the game

Keep up the good work.

[garfield]

This is quite impressive, especially given the RAM limitations.

[Dave_E]

I've just played through the 'b' version of the game. I echo that this is really amazing so far.

I didn't manage to make more than my opening balance on my first playthrough. I think I caught about ten ghosts and I had the Ghost Bait so was able to avert Marshmallow attacks. I also bought the vacuum.

Here are some thoughts on it, probably you're aware of some of them already.

1. It seems really hard to place the men on the ghost screens. A short tap of the 'fire' key never works. You have to really hammer it both to place a man and to start the streams. It's really annoying and distracts from the ease of the original.

2. It seems quite hard to catch the ghosts, much harder than the SNES or the Spectrum versions in fact. I'm not sure if the streams are just a few pixels too short - the ghost I thought I had pinned perfectly between the streams somehow managed to escape over the top of them on a few occasions.

3. The vacuum effect on the car travel screen is missing, but vacuuming the ghosts does work as you'd expect otherwise.

4. There's no key (keymaster) and lock (gatekeeper) milling about on the streets, like there is in other versions of the game. I know they're not technically necessary but I liked this effect. Any chance they could be added?

5. On one occasion, I went to a red building and captured the ghost. When I returned to the map screen, the marshmallow man arrived *instantly* and destroyed a building causing $4,000 of damage and giving me no time at all to drop the bait to save the cash. In fact, the Ghostbusters logo had not even appeared on the map screen. I've never seen that happen on any other version so that seems to be a (serious) bug.

I think, even in its current state, it could qualify as a finished product. Thanks so much for writing it.

[ChrisB]

Hi Dave,

Thanks for taking the time to play through. To address your points.

1. It seems really hard to place the men on the ghost screens. A short tap of the 'fire' key never works. You have to really hammer it both to place a man and to start the streams. It's really annoying and distracts from the ease of the original.

Yes - this is a known issue - and will be fixed in the next version.

2. It seems quite hard to catch the ghosts, much harder than the SNES or the Spectrum versions in fact. I'm not sure if the streams are just a few pixels too short - the ghost I thought I had pinned perfectly between the streams somehow managed to escape over the top of them on a few occasions.

I was feeling this might be the case. I there is a collision detection bug in this version that means the ghost passes through the top of the streams. I might look to restrict it's maximum height some more. I'm also not quite happy with the movement and this might be tuned.

3. The vacuum effect on the car travel screen is missing, but vacuuming the ghosts does work as you'd expect otherwise.

This is one of those "if I get space" animations unfortunately. I will see what can be done but I'm fully intending to have this in the SW ram version.

4. There's no key (keymaster) and lock (gatekeeper) milling about on the streets, like there is in other versions of the game. I know they're not technically necessary but I liked this effect. Any chance they could be added?

This was a decision I took a couple of versions back and I just don't have the space for them. They will return in the SWRAM version though.

5. On one occasion, I went to a red building and captured the ghost. When I returned to the map screen, the marshmallow man arrived *instantly* and destroyed a building causing $4,000 of damage and giving me no time at all to drop the bait to save the cash. In fact, the Ghostbusters logo had not even appeared on the map screen. I've never seen that happen on any other version so that seems to be a (serious) bug.

I'll need to look into this. From what I can tell the Marshmallow man on the C64 tends to appear as you re-enter the map screen. Sounds like the GB logo missing is giving the feeling that you can't press Bait but you should be able to.

There are some balance issues to address - I think the ghost capture reward needs to be a little higher and the time that you have to react to the marshmallow man needs tuning. If you have any other comments about how the pace of the game feels (number of houses going red and similar) I'd be interested to hear.

[fwibbler]

This is looking and playing well now, with the following exceptions: (and bear in mind I've only ever played the Spectrum version of this (I'll ignore the Sega version)
1. When returning to GHQ, there is no animation of the 3 men running out of the door to the car. (this maybe down to lack of space but I thought I'd mention it.
2. At one point (I think it was on the map screen), my cash showed as $7?00
3. The B key doesn't work if the ghost have started to assemble.
4. 3 times during my game, the ghost flew straight through the proton stream, thus escaping my trap.
5. Finally, the game ended while I was actually catching a ghost. On the Spectrum version it lets you catch the ghost (and get paid for it) and then when you return to the map screen the game ends (or moves on to the Marshmalllow door thing stage)

Hope this helps.
Cheers!

[ChrisB]

Thanks for the feedback. I'll take a look at these. Ghost movement seems like it's the biggest issues at the moment so I think I'll concentrate on that first.

[Dave_E]

Hi ChrisB,

Just played it through again. I'm attaching a few save states showing a few issues:

1. Ghostbusters-With-Question-Mark.uef
This is mentioned above, the money is corrupted with a ? appearing.

2. Ghostbusters-With-Less-Than-Sign.uef
This may be the same bug, the money is corrupted with a < appearing.

3. Ghostbusters-Flocking-Without-GB-Icon.uef
This is a bug that seems to occur if you catch a ghost and then return to the map. The GB sprite isn't plotted before the marshmallow routine and ghosts 'flocking' effect starts.

4. There's also a small bug (doesn't need a save state) if you try to visit a red building with no empty traps. The scrolling message "YOU HAVE NO EMPTY TRAPS" isn't cleared. When I hammered on the UP key to visit the property, it started scrolling the 'part-scrolled' message and looked ugly. Probably a 2 min fix.

[Cybershark]

Haven't tried the latest builds yet but, from looking through a comparison of the various versions, I think Mr Stay Puft should appear a bit more grand.



A couple of the versions there have him barely bigger than the player sprites, which just don't sit right! Can he be easily scaled up in your version to be more intimidating (and truer to his scale in the film)?

[ChrisB]

It's largely a matter of memory. Current sprite height 20 pixels. Marshmallow man is currently 64 pixels tall (3.2 times the man). C64 marshmallow man is 84 pixels tall (4.2 times the man). This would take about another 40 bytes of the 230 that I have remaining. How important is this compares to - say - some more animations at screen transitions? Right now I'll leave him be - but I think I could use a variant on the C64 version for the SW RAM Version.

[Cruxinc]

this game looks great!
do you have any tips for someone(me) learning basic who wants to eventually go on to assembly?
it looks so confusing!
thanks and have a good day

[ChrisB]

This version addresses some of the concerns raised. Changes are as follows:

• Gone through the code and optimised for space - now 280 bytes free.
• Updated loader to use new compression routines.
• Fixed "Action" not working on capture screen.
• Changed ghost movement on capture screen from random movement to circular. This should make ghost capture more predictable - feedback appreciated.
• Corrected an issue causing the top of the beams not interacting with the ghost.
• Game no longer ends whilst you are on the capture screen.
• Automatic movement and quit on ghost capture screen when there is no ghost.
• If a building times out when you are on the capture screen the ghost will leave.
• Changed the colour of the large arched door to green.
• Displayed ghostbusters logo on map screen whilst ghosts are moving for marshmallow man. This is simply a visual update as it was always possible to press the B key here (I could prevent the marshmallow attack on the saved state supplied). I've also slightly increased the time allowed to press B. This is not linked to the ghosts assembling so you need to be quite quick - although you have 40% more time if you have the marshmallow detector. I could change this to be simply any time whilst the ghosts assemble - with some extra time at the start if you have the detector. Again - feedback here appreciated.

There are still some things to finish up here so I'm going to leave "nice to haves" until later. However I've looked at the requests above.
Increased marshmallow man size - This might be possible. There is currently an unused reflection of the capture ghost. My intention was to change the capture ghost sprite depending on the direction it was moving however it doesn't look too bad at the moment so I could use this space (30 bytes) to increase the marshmallow man.
Animation on leaving GBHQ. I've implemented this - however it's around 115 bytes larger than the current routine - which is a significant chunk of the leftover space. Given the other things I have to do I'm not sure this will make the cut for the "standard" version - it will definitely be in the the SWRAM version though.

I've also noticed some missing things that need adding. Most notably this is the limited incidental sound including some replacements for the speech. This should be relatively simple but needs doing. I also need to add logic for the portable laser confinement system (should be small).

gb.ssd

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Edit: Cruxinc - Basically have a project as a target - say a simple invaders game or similar. Assembler is just like BASIC if you could only use GOTO, GOSUB, RETURN, IF, ?, AND, OR, EOR, addittion, subtraction and multiply and divide by 2, and you only had three 8 bit variables. Just requires breaking things down into smaller steps.