Along Came a Spider...

Pedro Lambrini · Post by **Pedro Lambrini** » Fri Mar 27, 2009 3:57 pm

It looks like Kenz is releasing Psytroniks first Vic 20 game:

http://psytronik.blogspot.com/

Sounds like quite a nice game. A definite purchase for me - especially after the news of the probable closure of Cronosoft.

Here's hoping there's plenty more Vic goodness on it's way from Kenz and his cronies!

jdxpolygon · Post by **jdxpolygon** » Sat Mar 28, 2009 8:16 am

That's my game

Just need to get PSYTRONIK onto the title screen, and get it loading from tape, and it's ready.

Kweepa · Post by **Kweepa** » Sat Mar 28, 2009 10:39 am

Can you tell us a bit more about it? About the production process?

Pedro Lambrini · Post by **Pedro Lambrini** » Sat Mar 28, 2009 1:01 pm

Yeah, I'm nosey too. It's always interesting hearing about the 'process'. Out of more interest did you contact Kenz or did he suggest it? Was there a lot of work needed to make this a 'commercial title?? Told you I was nosey!

jdxpolygon · Post by **jdxpolygon** » Sun Mar 29, 2009 1:08 pm

Not sure if its the development process you want to know about, or the process of getting it published.

Development-wise, it's taken me since about October last year (in short occasional bursts of productivity) to make the game. I cross-developed it on PC using C64ASM (bad choice - had to go back and hand-code zero page references to save memory

). I did my character graphics in one of Covert Bit-Op's C64 tools. Levels were designed on a tile-map editor first, and then manually converted to a 'plotter' style proprietary format, which fits a full screen level into about 70 bytes on average.

I wouldn't say there was a particularly large amount of work required on my part to make this game commercial, no more than anyone else making VIC-20 games in recent years has put in. I'd like to think it's of similar quality to some of the Cronosoft games you'll have seen (or created

) in recent times.

Kenz had mentioned wanting to expand to other formats in an interview in Retro Gamer magazine, and one of the formats mentioned was VIC-20. I had just recently got interested in programming the VIC-20 (as opposed to the C64) as I had bought a VIC-20 from a work colleague to save it from the car boot sale/rubbish tip. I'd initially sent an email to Cronosoft about the game when it was in development but didn't get a response. A month or two later I bought some Psytronik games and was impressed by the quality of their products, so when I finally got around to finishing the game in Jan/Feb this year, I sent a near-complete version for Kenz to take a look at, and he said he'd like to publish it. He got Smila to create cover artwork for it, and I looked into how to do the duplication (I don't think Kenz has a working VIC-20 (or any VIC-20), mines as I've said is on it's last legs, which is why I've looked into making a mastering program on the C64 instead). And that brings us up to now

I've just got a few non-gameplay-related modifications to make, and finalize the mastering solution, and then it'll mainly be over to Kenz to do his production/distribution magic.

If theres anything else in particular you'd like to know about the game, let me know

Post by **Jeff-20** » Sun Mar 29, 2009 2:03 pm

Robin was right. I would like to publish a game too!

Does anyone know how BinaryZone works? I would like to brand and package my own. Maybe I could just do it myself and mail it from here.

Pedro Lambrini · Post by **Pedro Lambrini** » Sun Mar 29, 2009 5:19 pm

I would presume the mastering process to be the most difficult part.

@ jdxpolygon. What are your plans with regards to mastering? Maybe it would help Jeff get into it.

It's a shame that Cronosoft is, presumably, down the tubes. He only published 3 games for the Vic but they were all great. As an aside, do you have plans for future releases?

TBH, I had considered getting into publishing games for the VIc a while back but the amount of stuff I would have to learn and buy (gear for mastering tapes, printing and art stuff, sourcing cassettes etc...) put me off. Then RL got in the way and it's never happened.

jdxpolygon · Post by **jdxpolygon** » Sun Mar 29, 2009 5:52 pm

Pedro Lambrini wrote:I would presume the mastering process to be the most difficult part.

@ jdxpolygon. What are your plans with regards to mastering? Maybe it would help Jeff get into it. It's a shame that Cronosoft is, presumably, down the tubes. He only published 3 games for the Vic but they were all great. As an aside, do you have plans for future releases?

TBH, I had considered getting into publishing games for the VIc a while back but the amount of stuff I would have to learn and buy (gear for mastering tapes, printing and art stuff, sourcing cassettes etc...) put me off. Then RL got in the way and it's never happened.

I'm just off to bed so I'll give you a quick answer on this

I'm pretty sure Kenz does all his C64 duplication from actual Commodore hardware, i.e. real datasettes. It seems to me like a good idea, I imagine the reliability of that is pretty good, where (relatively) small batches of copies are needed. The problem I have with CTS is that it initially uses screen memory for some data, and as far as I can tell there's no good way to load in/save out data from screen memory on an unexpanded VIC without the data being corrupted by system text output. I think the game's too big to have a de-crunching algorithm in with it, so I don't think I can make it a single file game. My idea was either to save the various parts out in kernal tape format from a C64 application (where the memory area $1000-$1FFF isn't interfered with by the system and there's plenty of extra memory to move things around), or to use a program like WAV-PRG to assemble a WAV with all the relevant memory regions output in the right sequence. The problem with the first solution is I was advised that different clock timings between the VIC and C64 in PAL territory could raise incompatibilities (although C64->VIC is supposedly alright). The problem with the WAV solution is, then you're moving to an 'audio' duplication procedure more or less, rather than direct from code, and that might not be ideal for Kenz. Then again either solution might be fine

My first go at a mastering program flopped, probably just made a mistake somewhere in there. I'll give it another go soon, I've just been preoccupied lately with my day job (which is also games programming

).

With regard to future releases, no specific plans on the VIC yet, but since I invested a little bit of time in getting the software sprites working, I would like to re-use it - when I started on Carling, I temporarily diverted into another game idea before going back, so I may revisit the other idea if everything on CTS goes well.

I think you hit the nail on the head, the two main bottlenecks are duplication and product packaging, and thats where Kenz/Psytronik shine through. I think the actual duplication process is still evolving, but the whole presentation side of things is very authentic.

Kweepa · Post by **Kweepa** » Sun Mar 29, 2009 11:02 pm

jdxpolygon wrote:I think the game's too big to have a de-crunching algorithm in with it, so I don't think I can make it a single file game.

I'd be very surprised if pucrunch didn't work for you:
http://www.cs.tut.fi/~albert/Dev/pucrunch/

jdxpolygon · Post by **jdxpolygon** » Mon Mar 30, 2009 3:40 am

Kweepa wrote:
jdxpolygon wrote:I think the game's too big to have a de-crunching algorithm in with it, so I don't think I can make it a single file game.
I'd be very surprised if pucrunch didn't work for you:
http://www.cs.tut.fi/~albert/Dev/pucrunch/

Can you tell me more about how it works? Literally every byte from $1000 to $1FFF is occupied at the start of the app ($1E00-$1FFF is then moved to OS space) so where does the decrunching code go? I think I've just figured it out, it relocates itself to OS space

I'll look into it.

carlsson · Post by **carlsson** » Mon Mar 30, 2009 5:29 am

If your program is really tight coded however, it may not be able to crunch the c:a 20-25% required (512 bytes + decompressor) to get a single filed version. But wonders have been made with customized versions of Pucrunch, e.g. Marko managed to get a single filed version of Pinball Wizard, which is one of the top 5-10 most crowded games I know for the unexpanded VIC-20.

jdxpolygon · Post by **jdxpolygon** » Mon Mar 30, 2009 8:44 am

I'll give it a go when I get home today. It'd be very handy if it did work!

Something I'm starting to think about as well now is NTSC - what needs to be done to make a game NTSC compatible, is there a chance my game already is?

Kweepa · Post by **Kweepa** » Mon Mar 30, 2009 2:26 pm

jdxpolygon wrote:Something I'm starting to think about as well now is NTSC - what needs to be done to make a game NTSC compatible, is there a chance my game already is?

If you haven't changed the screen size from 22x23 and you aren't timing your sprite drawing, then it should just work. Stick it in VICE and see.

If you have changed the screen size and position, then you'll need to check for NTSC and set the screen X and Y appropriately. There's a recent thread in the Programming section talking about the various ways to detect and handle that.

If the game runs off a raster interrupt and is tight on timing, you might be in trouble, since there's 20% less time per frame on NTSC, and the processor ALSO runs 10% slower. For Blue Star I had to spread the object updates across multiple frames (and double the movement speed of the objects that thunk once a frame).

Thanks for the development info by the way! Any info about the game itself? Number of screens? Any music? Gameplay?

jdxpolygon · Post by **jdxpolygon** » Tue Mar 31, 2009 3:14 am

Kweepa wrote:
jdxpolygon wrote:Something I'm starting to think about as well now is NTSC - what needs to be done to make a game NTSC compatible, is there a chance my game already is?
If you haven't changed the screen size from 22x23 and you aren't timing your sprite drawing, then it should just work. Stick it in VICE and see.

If you have changed the screen size and position, then you'll need to check for NTSC and set the screen X and Y appropriately. There's a recent thread in the Programming section talking about the various ways to detect and handle that.

If the game runs off a raster interrupt and is tight on timing, you might be in trouble, since there's 20% less time per frame on NTSC, and the processor ALSO runs 10% slower. For Blue Star I had to spread the object updates across multiple frames (and double the movement speed of the objects that thunk once a frame).

Thanks for the development info by the way! Any info about the game itself? Number of screens? Any music? Gameplay?

Thanks for that advice - I tried switching VICE over to NTSC to see how well it worked - the game seemed fine, it did occasionally jitter every few seconds but I'm not sure if that's VICE or my game. The game's speed is only tied to polling the H-line register, I can't remember exactly which line it refers to for this. I'm not actually sure if Psytronik is catering to an NTSC market as well, it hasn't been discussed yet anyway. Since its possible that tapes will be duplicated on the C64 for PAL VIC-20s, is it likely that these tapes won't load on NTSC VIC-20s? If they were duplicated on a PAL VIC-20, would that work better?

Ok, a little info about the game. I managed to fit in 8 screens, which repeat over 3 difficulty levels, eventually mirrored horizontally. Once you reach a difficulty level (indicated by the border colour) the game stays at that difficulty so you don't have to start from the easiest difficulty again. There's a little tune on the title screen, and quite a good number of sound effects in-game. Gameplay is 50fps, the character moves around pretty quick and by the 3rd difficulty level, the enemy balls move seriously fast as well. Jumping is gravity-based (like your Blue Star game). You've got full horizontal control of the character throughout the jump, again like Blue Star. As I mentioned before the game uses software sprites that can be drawn at any X/Y, and they OR together and colour-clash with the background/other sprites, rather than move infront of/behind. Most (well all) of the animation in the game is for the spider character, he runs, jumps, and gets squashed by the balls

Mike · Post by **Mike** » Tue Mar 31, 2009 3:54 am

jdxpolygon wrote:... - the game seemed fine, it did occasionally jitter every few seconds but I'm not sure if that's VICE or my game. The game's speed is only tied to polling the H-line register, I can't remember exactly which line it refers to for this.

The following discussion in the thread 'QUIKMAN 2008 for the unexpanded VIC 20' might be very interesting to you in that regard.

(Hint: It's not VICE)

http://sleepingelephant.com/ipw-web/bul ... 3&start=65

Michael