David Youd
David Youd
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Silicon Warrior mystery: Intro to Retro Debugger and 6502Bench
Exploring a 40-year-old C64 game mystery using the reversing tools Retro Debugger and 6502Bench.
Updates:
- 16 hours after I posted this video, Markus Fritze analyzed the Atari version of Silicon Warrior in Ghidra, and posted that the black hole logic is as simple as add 3 then mod 25, WAY easier to predict than the Commodore 64 version. Thanks Markus!
- The Retro Debugger's Debug Events comments bug has been fixed (in 5/25/24 release)
Links:
Retro Debugger (v0.64.66 with embedded Vice 3.1 in video)
- download: github.com/slajerek/RetroDebugger/releases/
- documentation: github.com/slajerek/RetroDebugger/blob/master/docs/README-C64-65XE-NES-Debugger.txt
- donation link: tinyurl.com/C64Debugger-PayPal
6502bench (v1.8.5 in video)
- download: github.com/fadden/6502bench/releases
- documentation:
-- reference manual: 6502bench.com/sgmanual/index.html
-- tutorial: 6502bench.com/sgtutorial/
Silicon Warrior (Epyx / The Connelley Group, Atari 1983, Commodore 64 1984)
- Atari manual: archive.org/details/silicon-warrior-epyx/mode/2up
- C64 manual: archive.org/details/silicon-warrior-c-64-manual
zhlédnutí: 1 103

Video

Alter Ego, Explained in 64 Seconds
zhlédnutí 164Před 4 měsíci
Alter Ego, explained in 64 seconds. Created by Dr. Peter J Favaro. Links: - Dr. Favaro's books: www.goodreads.com/author/list/1344083.Peter_J_Favaro Alter Ego Reviews: - Digital Antiquarian's take: www.filfre.net/2014/11/alter-ego/ - Digital Antiquarian's wife's take on the female version: www.filfre.net/2014/11/dortes-view-alter-ego/ - www.c64-wiki.com/wiki/Alter_Ego - www.thealmightyguru.com/...
CRX2023: Mark Lemmert, Nox Archaist technical deep dive
zhlédnutí 270Před 10 měsíci
Mark Lemmert gives a deep dive into some of the technical underpinnings of Nox Archaist. Topics include A* search for NPC schedules, data compression, performance optimization, and 5-bit sound on a 1-bit Apple II speaker. Links: - www.crxevent.com/ - www.6502workshop.com/p/nox-archaist.html
CRX2023: Piracy AI vs. a Python script
zhlédnutí 235Před 10 měsíci
A discussion on the algorithms used in 8-bit game AIs; uses the game Piracy as a concrete example. Links for stuff mentioned in the talk: CRX 2023: - www.crxevent.com/ The python script: - github.com/c64cryptoboy/explainedIn64Seconds/blob/main/piracy/piracyAI.py Piracy game: - Piracy, Explained in 64 Seconds: czcams.com/video/_Nb6iEZDy18/video.html - Scans of the instructions are here, for both...
Piracy, Explained in 64 Seconds
zhlédnutí 725Před 10 měsíci
Piracy (game), explained in 64 seconds. Programmed by Clive Barrett. Notes: - Scans of the instructions are here, for both the C64 game and boardgame versions: archive.org/details/piracyInstructionsC64GameAndBoardgame - C64 game instructions say you win by blowing out all the enemy port holes. I tested this, and it does not generate an immediate win against a 2nd player, only killing all pirate...
DIY Musicbox River Lullaby - Prince of Egypt (1998)
zhlédnutí 1,2KPřed rokem
Music box arrangement of the song Jochedbed sings to her child as she sends him away on the river Nile, saving him from the Pharaoh's decree to kill all newborn Hebrew males. River Lullaby was composed by Hans Zimmer/Stephen Schwartz for the animated film Prince of Egypt (DreamWorks 1998). Ruby Noosa requested the music strip pattern, so here it is: youdzone.com/music/riverLullabyeV1.0.jpg
Introduction to Ghidra: Commodore 64 Copy Protection Analysis
zhlédnutí 3,5KPřed rokem
TOC: 0:00 Introduction 3:11 Basics of Ghidra and 6502 assembly 11:12 Introducing floppy disk copy protection schemes 16:39 Start of Robots of Dawn copy protection analysis 25:52 Using python window to perform deobfuscation 30:13 Introducing custom scripts 34:57 Crash course in CBM DOS calls 39:45 Code relocation using the python window 42:35 Searching binary for strings 54:11 Protection reveale...
Juke Box, Explained in 64 Seconds
zhlédnutí 156Před rokem
Many thanks to my fellow youtuber, retro-gamer, and music buddy Glenn Case for donating this episode. :) Glenn links: - CZcams video games: www.youtube.com/@glenncase-videogames421/videos - CZcams music: www.youtube.com/@glenncase/videos - Glenn has a ginormous internet footprint, here's the best place to get started: glenncase.com (or linktr.ee/glenncase) Juke Box manual: archive.org/details/j...
Make Your Own Murder Party, Explained in 64 Seconds
zhlédnutí 280Před rokem
Make Your Own Murder Party, Explained in 64 Seconds
Sword of Fargoal (VIC-20), Explained in 64 Seconds
zhlédnutí 697Před rokem
Sword of Fargoal (VIC-20), Explained in 64 Seconds
Music Construction Set, Explained in 64 Seconds
zhlédnutí 580Před rokem
Music Construction Set, Explained in 64 Seconds
Spot (C64) vs. Ataxx (Arcade)
zhlédnutí 198Před rokem
Spot (C64) vs. Ataxx (Arcade)
Infection, Explained in 64 Seconds
zhlédnutí 147Před rokem
Infection, Explained in 64 Seconds
Realm of Impossibility, Explained in 64 Seconds
zhlédnutí 405Před rokem
Realm of Impossibility, Explained in 64 Seconds
C64anabalt, Explained in 64 Seconds
zhlédnutí 891Před rokem
C64anabalt, Explained in 64 Seconds
Lords of Conquest, Explained in 64 Seconds
zhlédnutí 630Před rokem
Lords of Conquest, Explained in 64 Seconds
Rocky's Boots, Explained in 64 Seconds
zhlédnutí 590Před rokem
Rocky's Boots, Explained in 64 Seconds
Archon, Explained in 64 Seconds
zhlédnutí 1,1KPřed rokem
Archon, Explained in 64 Seconds
Lode Runner, Explained in 64 Seconds
zhlédnutí 832Před rokem
Lode Runner, Explained in 64 Seconds
10-line BASIC game: DuetHero (VIC-20)
zhlédnutí 319Před 2 lety
10-line BASIC game: DuetHero (VIC-20)
Ultima III Soundtrack
zhlédnutí 3,5KPřed 2 lety
Ultima III Soundtrack
8-Bit Symphony: Kentilla (Rob Hubbard)
zhlédnutí 343Před 2 lety
8-Bit Symphony: Kentilla (Rob Hubbard)
CRX2021: The Runic Commodore 64
zhlédnutí 448Před 2 lety
CRX2021: The Runic Commodore 64
CRX2021: Chris Abbott interview "The Little Book of Sound Chips"
zhlédnutí 126Před 2 lety
CRX2021: Chris Abbott interview "The Little Book of Sound Chips"
Anastasia DIY Music Box "Once Upon a December"
zhlédnutí 3,8KPřed 3 lety
Anastasia DIY Music Box "Once Upon a December"
Sheet music excerpts from C64 JollyDisk Yule Log Juke Box
zhlédnutí 349Před 3 lety
Sheet music excerpts from C64 JollyDisk Yule Log Juke Box
World of Commodore 2020: Chris Abbott Interview
zhlédnutí 299Před 3 lety
World of Commodore 2020: Chris Abbott Interview
Candy Fun Tube (social-distanced trick-or-treating)
zhlédnutí 1,1KPřed 3 lety
Candy Fun Tube (social-distanced trick-or-treating)
Hundred Acre Wood Music Box
zhlédnutí 901Před 3 lety
Hundred Acre Wood Music Box
CRX2020: ChiptuneSAK
zhlédnutí 455Před 3 lety
CRX2020: ChiptuneSAK

Komentáře

  • @andrewdunbar828
    @andrewdunbar828 Před 7 dny

    I'm not a C64 guy but I am an 8-bit era guy and a reverse engineering guy and a Ghidra guy and this video hits all of those spots! I'm now working on my own bunch of stuff for using Ghidra with Retro systems just for fun.

  • @jamessager5358
    @jamessager5358 Před 9 dny

    Archon is the most confusing game ever.

  • @MichaelDoornbos
    @MichaelDoornbos Před 22 dny

    This video is a diamond in the rough. So much to unpack.

  • @Nemethon
    @Nemethon Před 23 dny

    I played this game so many times, all the music is burned forever into my mind. ;D

  • @partitionhlep
    @partitionhlep Před 28 dny

    awesome rendition!

  • @doctechno2241
    @doctechno2241 Před 29 dny

    VC-20 Gorf has such a distinct "PEW" sound for your laser that it stands out amongst all of the versions. Pretty good port for such a limited computer.

    • @DavidYoud
      @DavidYoud Před 29 dny

      Yah, Commodore did a great job with both the Gorf and Omega Race ports on the VIC-20. One of these days, I'm going to disassemble one (or both) to see what clever soft-sprite techniques they may have used.

  • @THX723
    @THX723 Před měsícem

    Loved this game!

  • @charlesfatt
    @charlesfatt Před měsícem

    One of my favorite games. Thanks for the video.

    • @DavidYoud
      @DavidYoud Před měsícem

      Hey, I see you just dropped a new Lode Runner video yourself. :) Watching now...

  • @LordInvictus-yt
    @LordInvictus-yt Před 2 měsíci

    Excellent

  • @sa3270
    @sa3270 Před 2 měsíci

    Those were the times programmers could get away with stuff like that.

  • @anttimaki8188
    @anttimaki8188 Před 2 měsíci

    The 1st part of the Wander was my friends old nokia phone song.

  • @rootlabs
    @rootlabs Před 2 měsíci

    The Power of Jim is the only parameter anyone ever needs

  • @michaelokovit3926
    @michaelokovit3926 Před 2 měsíci

    Thanks

  • @MrNickharp
    @MrNickharp Před 2 měsíci

    Works every time😂🤙

  • @Daniel-Goodfeather
    @Daniel-Goodfeather Před 2 měsíci

    Beach Head, Castles of Dr Creep, Lode Runner, and Jumpman were some of my favorites as a kid.

  • @vincentleeadams
    @vincentleeadams Před 2 měsíci

    You could’ve also used goats blood.

  • @JMKLTII
    @JMKLTII Před 2 měsíci

    I remember those days like it was yesteryear. Pro tip, use goats. Less hurt for you and the C64 can't tell the difference

  • @DavusClaymore
    @DavusClaymore Před 2 měsíci

    Raid Over Moscow anyone? Or can I not mention that game?

  • @DavusClaymore
    @DavusClaymore Před 2 měsíci

    Fortunately my copy program never failed.

  • @8_Bit
    @8_Bit Před 3 měsíci

    Unexpected solution!!! :O

  • @yucelbilik
    @yucelbilik Před 3 měsíci

    Nice video, thanks.

  • @oliver4953
    @oliver4953 Před 3 měsíci

    Whenever that Logo appeared on my C64, I knew that a fun game with good quality was about to start. Electronic Arts was a good game company at that time. Good old times.

  • @hai.1820
    @hai.1820 Před 3 měsíci

    One of the best game tunes in history..

  • @MusicBoxlovesong-yf7yw
    @MusicBoxlovesong-yf7yw Před 3 měsíci

    This is the best song))))

  • @saganandroid4175
    @saganandroid4175 Před 3 měsíci

    Intuitive is not a word l have ever seen used to describe Retro Debugger.

    • @DavidYoud
      @DavidYoud Před 3 měsíci

      :D Maybe it's the kind of intuitive that means "easy to remember once you know" as opposed to "easy to discover". Either way, I found it more friendly than I expected.

  • @thefadden
    @thefadden Před 3 měsíci

    This is awesome! Great example of working with a disassembler and debugger together. I just wanted to mention a couple of things. - 1:28:45 there's currently no facility to apply a rewrite function (e.g. XOR) to obfuscated portions of the binary in SourceGen. (It's on the to-do list.) - 1:02:15 you can toggle the byte-combining behavior project-wide with Toggle Data Scan (Ctrl+D) when you just want to format something quickly. - 1:00:07 pre-labels are meant to provide access to the pre-relocation address for relocated sections, so the label stuff doesn't happen automatically. (I have a "label alias" item on the to-do list that might be what you want; for now you just have to put the group label on the first byte.) - 44:13 I often turn off "seek nearby targets". Maybe it shouldn't be on by default? It's either really handy or really annoying. - 36:47 if you're uncertain about a label, you can stick a '?' on the end. (If you don't feel like writing out "unknown".) - you can regain some horizontal screen space when recording a video by collapsing Flags and Attr, which are rarely useful.

  • @BRich057
    @BRich057 Před 3 měsíci

    Lastly I would like to propose an answer to your question about what to do with leftover code up concerning the 6502. I personally would renew, reuse and recycle all electricity that comes out of intelligent work. Because it gains knowledge the same as we do. So use those magic squares. Start by arranging those numbered tiles in silicon warrior according to the art. And the Black hole(a) will guide you in the ways of proper handling the now coherent electricity.

  • @BRich057
    @BRich057 Před 3 měsíci

    So if one takes the 3 magic squares and multiples each number by 3. You get 9, 12, 15. Add those together and you get 36. Which stands for 369 degrees also ,6*6. The 3 rd 6 comes from 15 not being able to divide into 36 evenly and so leaves a remainder of 6. Now add those 6's together and you get 18. Well 1+8=9 and 3 is the square root of 9..

  • @BRich057
    @BRich057 Před 3 měsíci

    Wow you are so amazing. I have been watching this video 1-3 times a day since finding it 4 days ago. I do have a hopeful piece of info that should lead to something phenomenal. Those tiles are ,5 wide and five deep. That is a magic square. There are 3 magic squares total that are currently known. And because these magic squares can be added or subtracted from each other. They make up all other squares. I believe the other 2 magic squares are 4 and 3. How many power pyramids are there on that screen. Also how many sides? 4 if you count the bottom. Lol

  • @pascalweill9635
    @pascalweill9635 Před 3 měsíci

    Very great work. What a pleasure to remind soft old days when playing Ultima III as a teen.

  • @8_Bit
    @8_Bit Před 3 měsíci

    That rewind to last read/write of a particular location would be amazingly useful. All this new-fangled stuff, it's going to put us all out of jobs!

  • @brileyh
    @brileyh Před 3 měsíci

    You are definitely a computer scientist. In a way, you are treating this entire video as a puzzle solving a game like Zork's twisty little passages. LOL! I have learned more about assembly language from THIS video than I did back in college. BTW- I hated coding at such a low level but it was a required course. Changing the labels makes it much easier to understand. Fun video watching how your puzzle solving mind works.

  • @RyanWeaving
    @RyanWeaving Před 3 měsíci

    Awesome video. Retro debugger looks super fun

    • @DavidYoud
      @DavidYoud Před 3 měsíci

      Hey old friend, long time no see. Yah, try out Retro Debugger on some old favorite game, you'll like it.

  • @puzzud
    @puzzud Před 3 měsíci

    Thanks for the video. I learned some good stuff that I will definitely try out. I use this program all the time but I guess didn't rtfm enough!

  • @markusfritze
    @markusfritze Před 3 měsíci

    Thanks again for such an informative video. For the heck of it, I've looked at the Atari code (with Ghidra and my Atari8BitGhidra plugin - it's on GitHub): completely different! I guess there was no shared source code - that was quite common at that time. The "rule of 3" on the Atari implementation: at game launch the variable for the black hole tile is set to 0. When a black hole should appear, the tile index is incremented by 3 and that's where the hole will appear. At 25 it wraps around. So, years, trivially to predict. And the comment suddenly makes sense.

    • @DavidYoud
      @DavidYoud Před 3 měsíci

      Whoa, thank you for so quickly answering the question I posed at the end of the video! I just found a youtube video showing the black holes on Atari gameplay, and yes, it's really as simple as t=(t+3)%25 in the original. :D I find it fascinating that (you determined that) the Commodore port didn't use any code from the Connelley Group's Atari original. Does anyone know who the original programmer is? Yes, Ghidra is quickly becoming well-suited for 6502 work. The most useful thing to me is the pcode emulation, which allows large windows of self-modifying 6502 code (common in copy protection) to update itself in the Ghidra dissessembly, just as it would on the 8-bit machine. On my c64_ghidra github, I wrote a rudimentary Ghidra emulator harness that gets the emulation job done, but it could certainly be improved upon. Once again, thanks for looking into this; you sir have officially put the nagging black hole question to rest. :)

    • @DavidYoud
      @DavidYoud Před 3 měsíci

      I added your findings to the video description in the updates section.

    • @markusfritze
      @markusfritze Před 3 měsíci

      ​@@DavidYoud You video about Ghidra I still watch ever now and then. It is such a well done video on how to approach reverse engineering C64 code. I didn't know about 6502Bench, but I am on a Mac, so I try to avoid Windows.

    • @markusfritze
      @markusfritze Před 3 měsíci

      ​@@DavidYoud It was quite common to _not_ have the code for a port. Often the license for a specific platform was sold and the company then was looking for developers to write the code. If you were lucky, you had access to the original version, so you could see. That combined with schedules counted in weeks, it often resulted in quick ports. Also: we can't forget that often the development happened on the original machine as well. A machine without enough memory. So you see code with 1-character symbols and no comments at all. Today some old code can be found at GitHub, like Fort Apocalypse - it is really written to be compact. Been there, done that… Later (Atari ST, Amiga) cross-development was more common. I've developed an assembler (TurboAss) for the ST, which supported an output API. This was used to transfer via parallel cable code to e.g. an Amiga with a minimal stub. Crashes were caught and the TurboAss supported not just "GOTO line number", but also "GOTO address", so you could just enter the crash address to see where the crash happened. Turn-Arround times were less then 30s, not bad at the time.

    • @DavidYoud
      @DavidYoud Před 3 měsíci

      @@markusfritze I'm going to pin this thread to keep it on the top of the comments. :)

  • @75338
    @75338 Před 4 měsíci

    Did you get the chicken?

  • @EATABAGOFHELL
    @EATABAGOFHELL Před 4 měsíci

    floppy disk plastic only blocks visible light; it's completely transparent to the infrared that'll REALLY fuck your eyes up. it's like one of those cheap green laser pointers that lacks an IR filter: not enough visible light to produce pain or force your pupils to constrict, but more than enough IR light to fry your retinas. actually staring at the sun with your bare eyeballs would be better for you.

  • @fractalMD
    @fractalMD Před 4 měsíci

    Amazing

  • @MattKasdorf
    @MattKasdorf Před 4 měsíci

    Oh nutz would have been nice to know about this trick before the eclipse 😮

    • @DavidYoud
      @DavidYoud Před 4 měsíci

      I'm not sure if it's eyeball-safe, but it's 8-bit fun. ;)

  • @aliciafernandez1206
    @aliciafernandez1206 Před 4 měsíci

    Had all the nurses outside with the floppies too 😂

  • @aliciafernandez1206
    @aliciafernandez1206 Před 4 měsíci

    Niiiiice!!!!

  • @Tamir.servis
    @Tamir.servis Před 4 měsíci

    super

  • @nikolajosorov4941
    @nikolajosorov4941 Před 4 měsíci

    Thank you! Please more of that

  • @aethermass
    @aethermass Před 5 měsíci

    From the wiki entry: Alter Ego was the first game that was also released in a "female version". Furthermore, it was the first game to get a "parental warning". Sounds like something everyone should play at ~14. Bonus points for not being woke =)

  • @Wasabialt
    @Wasabialt Před 5 měsíci

    Explain Mama Llama in 64 seconds.

  • @anarespicio-ki1sr
    @anarespicio-ki1sr Před 5 měsíci

    Favorito amei esto🎁

  • @BeyondWrittenWords
    @BeyondWrittenWords Před 6 měsíci

    legendary

  • @ronmartinez8781
    @ronmartinez8781 Před 6 měsíci

    Hey! Nice work. I produced and developed this, and wrote The Big Kill. Thanks for your review!

    • @DavidYoud
      @DavidYoud Před 6 měsíci

      I'm so pleased that you dropped by! Thanks for adding this fun memory to my childhood. :)

  • @LetsNeverPlayAgain
    @LetsNeverPlayAgain Před 6 měsíci

    Fairly good SID interpolation but feels slightly different than what I remember on hardware?

  • @psycho.artist
    @psycho.artist Před 6 měsíci

    Woah this is so cool!