View Full Version : 65C816 assembly (IIgs)

Oct 27, 2002, 05:33 PM
I have a IIgs, the ORCA/M assembler, and full set of programming books for the IIgs (actually, I stole them from Arn, and the IIgs monitor I am using as well). I toy with the idea of getting into 65C816 assembly on that machine. The 65C816 seems a perfect balance of power vs. complexity if you ask those who have programmed it (as opposed to, say, x86 or 680x0 assembly). There would be no practical reason to pursue this other than to have tried my hand at asm in a non-academic setting. (In college I spent a semester doing a significant amount of x86 assembly language, having written a graphical Battleship game to be run on two serial-linked computers that played each other---fun stuff, be sure.)

Anyone ever think of going down such a road?


Oct 28, 2002, 04:28 PM
I took a semester of 68K programming as well. It is required for graduation here still (builds character I guess). The most complex thing that I did was a CLI calculator that parsed the input args and outputted a result (sort of like the Unix bc, a few hundered lines). Sounds like you really got into the assembly scene with serial i/o, graphics, and such. Assembler was probably more widely useful when you took it, due to hardware limitations of the time.

I also have a IIgs that I recently put a HD on and have started to tinker. Western Digital still maintains processors close to the 65C816, AFAIK. A lot of people still program in 68K assembler for the TI-89 and 92 which have a 68K architecture.

Assembler for the 65C816 would definitely be better than BASIC. I've thought about programming the IIgs, but I don't know how rewarding it would be beyond s&g. Definitely interesting though.

Oct 28, 2002, 10:40 PM
The DragonBall processor in current Palms has an embedded 68EC000, and as such there are certainly folks currently doing 68000 assembly. Some SCSI boards and other embedded devices have 68020+ on them still, and there's call for assembly there, as far as device BIOS, etc. I had a DPT SCSI board for a PC that had a 68000 10MHz on it, actually.

Good stuff.


Oct 29, 2002, 07:43 PM
Awww this is the best this reminds me of the old Apple 1 days. You guy's are awesome. Good Luck.

Aug 1, 2003, 05:45 PM
I just bought a ][GS because I'm a sucker for old hardware. I haven't even got it home yet to try it out, but once I get the system software running I plan on looking into development tools.

Probably the best bet would be to use a cross compiler on linux to build the application and an emulator for testing (pretty common approach). Of course getting it linked, loaded, etc. is an issue. ca65 appears to have a 65816 target, so it's a good place to start.


After years of developing software in C/C++ and Java for modern machines, I'm ready for a real challenge. I did some 6502 assembly back in high school and some 68k assembly in college, so I do have some idea as to what I am getting into.


Aug 2, 2003, 10:46 AM
I still have a 6502 machine available for assembly language programming, as well as other languages and playing games.

6502 assembly was just so sweet and I have a 65802 (6502-pin compatible 65816) but never found a machine for it. 68000 still has the best instruction set though, but you pay for it with complexity.