I held a talk about Amiga Cracktro Programming at the DevHouseFriday 2016-05 at Userlike offices. This is the cracktro i made for this talk.

1. Amiga Cracktro
Programming
DavidVoswinkel
david@optixx.org

2. About me
• Developer at www.userlike.com
• Hobby projects at www.optixx.org
• Gaming consoles
• Micro controller
• Retro computing

3. Motivation
• Learned programming on the Amiga 500
• Use modern development tools
• Interesting platform
• Total control
• Batteries included

4. Whats is a Cracktro?
• Spread with pirated games released by
cracker groups
• via mail letters , later via modem
• Mostly logo, text and music
• Demonstrate technical skills
• Competition & fame

5. Cracktros come in
many form
• Small, packed, absolute or relocatable
• Standalone, injected or in bootloader
• Compilations / Trainers

6. World of Wonders

7. Quartex

8. The Company &Vision Factory

9. Amiga History
• 1985: Amiga 1000
• 1987: Amiga 500 & Amiga 2000
• 1990: Amiga 3000
• 1992: Amiga 1200 & Amiga 4000
• 1994: Bankruptcy of Commode Inc

10. Amiga 500
• 16/32bit Motorola 68000 CPU
• 32bit registers
• 16bit databus
• 24bit external address bus
• 7 MHz
• 512KB RAM Chip Ram
• OCS
• Price 800 DM in 1988

11. Amiga 1200
• Motorola 68EC020 CPU
• 32bit register
• 32bit databus
• 24bit external address bus
• 14 MHz
• 2MB RAM
• AGA
• Price 900 DM in 1992

12. Custom Chips
• Original Chip Set (OSC)
• Enhanced Chip Set (ESC)
• Advanced Graphics Architecture (AGA)
• Advanced Amiga Architecture (AAA)

13. Original Chip Set
(OCS)

14. Agnus
• Controls Chip RAM
• DMA
• Access only 512KB of Chip RAM
• Hosts the Blitter and Copper

15. Blitter
• BLock Image Transfer - Blit
• 4 Channels, boolean combination
• Copy, clear and fill
• Draw lines

16. Copper
• Co-processor
• Commands: MOVE,WAIT and SKIP
• Programs are copperlists
• Set video hardware registers
• Change color registers mid-frame
• Create rasterbars

17. Denise
• Display encoder
• Lowres 320x256 @50Hz PAL 32 Colors of 4096 palette
• Hires 640x256 @50Hz PAL 16 Colors of 4096 palette
• Interlaced
• Extra-HalfBrite (EHB)
• 64 Colors
• Hold-and-Modify (HAM)
• 4096 Colors
• Dual playfields
• 8 Sprites 16 pixel width

18. Paula
• Audio and peripheral
• IO
• Floppy controller
• Serial port
• Mouse / Joystick inputs

19. Chunky vs. Planar
• Planar
• Represents pixels with layered bitplanes
• Info spread on different planes / RAM
locations
• Chunky
• Packed pixel
• Pixel are grouped together in RAM

20. Emulate vs Hardware
• Emulator
• WinUAE, FS-UAE
• Lots of emulated hardware
• Hardware
• Real hardware with Gotek floppy emu
• MIST FPGA

21. Coding 1988
• Seka assembler (later ASMone)
• IDE, compiler and debugger in one
• Project management
• Floppy disks
• Paper & pen
• Pocket calculator
• Documentation
• Books & Printouts
• Word of mouth (phone calls)

22. Load & compile

23. Run

24. Debug

25. Coding 2016
• Crosscompiler: vbcc, vasm68k and linker
• Texteditor + Git
• Emulators
• FS-UAE
• WIN-UAE
• Documentation
• Blogs & Forums

26. Hack…

27. Compile

28. Emulate

29. Debugger

30. Code Flow
• Save system state
• Turn system off
• SetupVBI
• Mainloop
• Jump to effects routine
• Jump to music play routine inVBI
• Restore system state

31. Effect Explained
• Logo Wobbel
• Create a copperlist that manipulates the image
• Static vs. dynamics
• Update copperliste
• Use sine LUT
• Use hardware scroll register for < 16px
• Bitplane scroll register for >16px

33. Getting Started
• Photon’s ASMSKOOL videos & resources
• http://coppershade.org/
• Amiga Cross Dev
• https://github.com/kusma/amiga-dev

34. My Cracktro
• Logo with wobble effect
• Horizontal rasterbars
• 2-pixel sinescroller
• Sinescroller mirror with water effect
• Background starfield

35. Now Live Demo!