nesdev.org

Lots of good comments - thanks, folks. I'm going to open tickets on my project for .setcpu (actually, more generally, "anything you can set by the commandline should be settable by an assembler pragma") and for the bankswitching extensions on the HuC6280 (the only bit missing from supporti...

How about 65816, Hu62c80, and 65c02 processors? 65816 and z80 support have never really been on the table for Ophis, since I don't have a personally compelling application for them and there's a lot of extra infrustructure involved in supporting it unused by the other systems. It's a lot closer to ...

I've just published a modernized version of my old "Ophis" assembler: http://michaelcmartin.github.com/Ophis/ It does seem like the community has largely standardized on CA65, which is a very good assembler indeed, but there are three reasons this may be of general interest: Its complexity...

This is a fun trick - I associate it with OO-style method calls, myself. I first encountered it in Gradius, which has longer code but which preserves the (non-A) registers for the same 4 bytes of RAM: asl ; A = A * 2 stx $9B ; Cache X and Y sty $9A tay iny ; Y = A + 1 pla ; Put RTS's return address ...

After some gentle prodding I've renewed development of my old "Ophis" assembler[1]. Part of this work is building up some basic "header files" for the platforms I want to support. This, of course, includes the NES. I've got two main questions as I work up the NES supporting mater...

P65 has been retired for awhile now, actually; it evolved into "Ophis" and doesn't require extra stuff installed. It's apparently closest to DASM in terms of expressive power, at least from the email I've received.

The Commodore 64 Programmer's Guide, chapter 5, is one of the best gentle introductions to 6502 machine language out there.