Here are some interesting resources if you want to code in assembler on Apple II.
This is absolutely not a complete list, your favorite search engine should give you a lot of results, but those are the websites that helped me the most.
Also, for generic 6502 algorithms, have a look at what the C64 scene can offer you!
Update 08/06/2019: added cc65 and Visual Studio Code
Generic 6502 and 65C02 reference
- 6502.org Tutorials – The reference site for 6502 and 65C02 CPUs
- Codebase64: 6502/6510 maths – One of many C64 resources for 6502.
- WUSDN IDE – Eclipse 6502 plugin that integrates assemblers, emulators and disk tools
- Visual Studio Code – C64 extensions add support for 6502 syntax coloring
- acme cross-assembler – 6502 cross-assembler that can generate A2 binaries
- cc65 cross-assembler – 6502 cross-development full package
- AppleCommander – A2 disk image utility (creation/modification)
- GrafX2 – Paint tool (Win/Mac/Linux), v2.6 supports RGB HGR and DHGR
- ADTPro – PC/Mac <-> A2 fast disk transfer tool through a null modem cable
- Bmp2DHR – BMP <-> DHGR/DLGR converter for NTSC Apple II
- Apple II documentation project – Amazing archive of A2 tech reference: check index.txt!
- Apple II graphics – Good overview of A2’s GR/HGR modes
- John Relay’s Apple II Archive – I/O Memory – Cheat sheet for A2’s hardware switches
- Apple II Double Hi-Res from the ground up – How to program DHGR
- DHGR – Pushing limits – Very complete writing on the mess that is NTSC DHGR
- Apple Underground – (French) Lot of information on Le Chat Mauve RGB cards, DHGR mixed-mode used in Extasie and differences between NTSC and PAL A2
- Apple II 64k cycle counting megademo – Amazing demo for Apple II+ by VMW prod
- Prince of Persia Code review – A great introduction to Apple II architecture
- festro – Festro by Digarok
- dos33fsprogs – Disk tools, and the Apple II demos by VMW prod
- Apple II PT3 Vortex Tracker Player – Vortex YM player by VMW prod
- a2-4am – Disk preservation and modern crack tools, .woz format
- Ctrl-Pomme-Reset – French Touch’s final code archive (GPLv3), contains a lot of unreleased demos/effects and good hardware detection functions
- Latecomer (party version) – My first A2 demo
- Prince of Persia Apple II – The official Prince of Persia source code by Jordan Mechner
Modern hardware upgrades for Apple II
- VidHD – Call-A.P.P.L.E.’s incredible HDMI card for Apple II
- Floppy Emu – BMOW’s floppy disk emulator for Apple II / Lisa / Mac. Can also act as a ProDOS hard drive if your Apple II has a smartport firmware.
- a2heaven – Many upgrades, you can get the Mega audio soundcard there (emulates every audio soundcard available for the A2).
- Apple2.net – Ian Kim’s website, home to the Mockingboard 4c for Apple IIc. He sells it on eBay when a batch is available.
- How to fix Apple Joystick’s buttons – Instead of buying another one 🙂
- Open Source Scan Converter – Converts analog RGB to HDMI, it works very well with Le Chat Mauve RGB cards and adapters.