My version of Space invaders for C64 (2021)

Mirazulado · Post by **Mirazulado** » Thu Mar 18, 2021 1:38 pm

Hi, friend. My name is Mariano and I would like to share a version of Space Invaders for commodore 64. I developed this version throughout 2020. It is my first assembly development and I would like your opinion about it.

Download: http://pastbytes.com/mkalafatovich/

GamePlay: https://youtu.be/tUHQu4WB4Ss

Cheers! and long life to Commodore 64.

Mclane · Post by **Mclane** » Thu Mar 18, 2021 2:52 pm

Its great, the shot sound is odd but the rest is spot on, does it do the 13 shot thing where you count the shots to get a 300 ufo every time?

Mirazulado · Post by **Mirazulado** » Thu Mar 18, 2021 3:37 pm

Yes! the ufo point table is the same as the original. Also, the appearance of the ufo screen depends on whether your shots were odd or even since the game started. Sound is a problem. The original machine has four channels of analog sounds. It is very difficult to adapt it to the three channels of the c64. MAME uses digitized sounds due to the difficulty of emulating in analog sound. Thank you very much for the opinion!

Mirazulado · Post by **Mirazulado** » Thu Mar 18, 2021 4:20 pm

the original trigger sound is two generators mixed together. One is a rare sine / square signal mixed with a noise generator. both have a long vibrato and pass through filters, all analog. In the 80s the clones simply changed the sound for a simpler shot. In the 90s sampled sound was used. There are still discussions of what the original sound was because it was analog and there were hundreds of pirate clones.

Rhialto · Post by **Rhialto** » Thu Mar 18, 2021 4:43 pm

Looks great! Congrats. Why have you disabled comments on YouTube? Just curious.

Mirazulado · Post by **Mirazulado** » Thu Mar 18, 2021 4:54 pm

Thanks for the comment, it was my mistake to close the comments on youtube. I created the video as "content created for children". I'm sorry!

Richard of TND · Post by **Richard of TND** » Thu Mar 18, 2021 6:09 pm

Wow. That is two or three space invaders games in one season. I saw Sprite Invaders, also mini Invaders. Now this game. Nice conversion. Another for my C64 collection

ricky006 · Post by **ricky006** » Thu Mar 18, 2021 6:23 pm

I like it

Neo-Rio · Post by **Neo-Rio** » Fri Mar 19, 2021 1:16 am

Very impressive!

So how close is this to a straight port/translation of the Space Invaders assembly code?
Any reason why you chose not to do samples of the sound?

willasm · Post by **willasm** » Fri Mar 19, 2021 3:24 am

Just tried this out. Very nicely done! Great version of a classic.
Thank you for sharing this with us.

STE'86 · Post by **STE'86** » Fri Mar 19, 2021 3:36 am

did you use bitmap or charset for this?

OneCheekyDevil · Post by **OneCheekyDevil** » Fri Mar 19, 2021 8:10 am

I haven't played the original enough to be able to compare this, but I'm impressed with the closeness of the graphics and sounds.

Congrats!

mrr19121970 · Post by **mrr19121970** » Fri Mar 19, 2021 10:44 am

STE'86 wrote:did you use bitmap or charset for this?

Video $0400, Charset $3800 (RAM)

MeneerJansen · Post by **MeneerJansen** » Fri Mar 19, 2021 11:32 am

Very nice port to the 64! Thanks man. The sound of the shot on the original Arcade machine sounds to me like noise through a high pass filter. Maybe you can fix that...

Mirazulado · Post by **Mirazulado** » Fri Mar 19, 2021 12:35 pm

Neo-Rio wrote:Very impressive!

So how close is this to a straight port/translation of the Space Invaders assembly code?
Any reason why you chose not to do samples of the sound?

do not use sampled sound in game as the commodore 64 can only play one channel of sampled sound and the space invaders requires four channels. With a lot of work I could reduce to three channels (SID) but it would be impossible to use only one channel.
Thank you very much Neo-Rio for the comment!

Kim Lemon Beer

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