Tuesday, February 08, 2005

Seibu SPI encryption

I'm looking at the Seibu SPI graphics encryption at the moment. For now, I'm fixing the small mistakes in the tilemap layers of Senkyu etc., after that I might look at the sprites as well.

Most of the work has already been done on the tilemap layer, but there are some mistakes. I have understood while they are happening and already fixed one of them. It's clear how the algorithm works, it's a bitswap + arithmetic calculations (additions instead of simple XORs - this is not common). Replacing the lookup table with formulas and fixing the remaining bugs is just a matter of time and patience at this point.

18 comments:

Anonymous said...

Nicola,

You are the greatest! Working on decryption is difficult and time consuming. It is great that you spend your time. I have always loved arcade games, and MAME is one way to rediscover the games I played as a child. Keep up the great work.

Stephen

Anonymous said...

This is really great news!

Anonymous said...

Thanks a lot Nicola, really thanks!!

Anonymous said...

You...are...so beautiful...to me.

Anonymous said...

/me is hoping on Raiden II.....all the very best of luck & may your hard work go as rewarded as it is appreciated!!

morpheus said...

Great blog !
Keep writing it for a long time.

I wrote an article about it:
http://morpheus.splinder.com/1107862442#4016421
Hope you'll like it.

Anonymous said...

thx for the hard work! really appreciate it :)
raiden dx on the way! :D

Anonymous said...

Raiden 2 and DX are not on seibu spi

Anonymous said...

Correct me if I'm wrong but these are teh games on Seibu SPI:-

Battle Balls
E-Jan High School
Gun Dogs
Raiden Fighters
Raiden Fighters II : Operation Hell Dive
Raiden Fighters Jet
Sen kyu
Viper Phase 1
Viper Phase 1 New Version

Anonymous said...

mille mille grazie dr.mathemtico :))))

Lillymon said...

Gun Dogs was the prototype name for Raiden Fighters. Aside from that, the Seibu SPI list posted is mostly correct, though some games referred to as Seibu SPI games are actually Seibu SYS386 games.

More info: http://www.mameworld.net/maws/driverinfo/seibuspi.c

Anonymous said...

Ah yes finaly your working on Seibu games, YEAH!!!!
Please don't give up on breaking the encryption codes and making them playable.
You are the best,and the very best of luck.

Anonymous said...

My dreams are anwsered, god bless you Nicola.

Anonymous said...

Yes, Yes!
Is it possible that we all can play the Raiden series and Viper Phase 1 series soon, I hope so.
Nicola you are the best!

Anonymous said...

Madonna che lavoro immane che ti sei sobbarcato, complimenti!
Se passi qui a Firenze, ti sei guadagnato un grandioso Chianti e la cheesecake della cioccolateria Hemingway.

Kekule
http://pastaaltonno.splinder.com

Anonymous said...

Nicola,

You are a genius! I have always loved arcade games and MAME is absolutely the best. I especially love the Raiden series and have been hoping for ages now that these will be playable in the future. I know that this may take a while to figure out but it's good to see that someone (especially someone with your talents) is working on this.

Many thanks for all your time spent and effort spent.

Anonymous said...

gods bless you nicola,s for all you have done for the emulation of arcade games, thank you for your time.

i have been waiting for seibu spi games to work. i can,t think of anyone better for the job.

gods help you.and keep up the good work.

Anonymous said...

gods bless you nicola,s for all you have done for the emulation of arcade games, thank you for your time.

i have been waiting for seibu spi games to work. i can,t think of anyone better for the job.

gods help you.and keep up the good work.