Both absolute and indirect addressing modes on the 65x are 16bit. 16bit addressing wasn't a stranger to 8bit cpu, it was the norm. If you mean indexing, then yeah - only 8bit. The 6809 cpu has 16bit indexing though.
I know that. My point though was more the fact that the 6502 lacks actual 16 bit registers to do the aforementioned things. It'd be nice if they used a CPU that did for the SuperGrafx. I'd venture to guess that it would be fine to use a 65816, since you can kick them into 65c02 emulation mode. I'd also guess that Hudson would come up with some hybrid thing anyways like they did with the 6280.
You should see the C64 w/ a SuperCPU. It's pretty wild. The one game for it (Metal Dust), pulls things off the C64 crowd could never dream of otherwise. The game's not exactly great, but it shows the difference you can actually get. the speed and the 16-bitting help a great deal. This is why all of those Doom/Wolf3D games for C64/Speccy/etc are pretty rough. You really need more bittage to achieve those kinds of things.
Imagine what you could do on the SuperGrafx with a 16 bit CPU that is faster than the 6280. I suppose, if Spenoza's idea of using the 6280 as a coprocessor went into effect too, you wouldn't need to worry about compatibility.
Something similar is often discussed in Amiga land. People think the Amiga line should have been backwards compatible with the C64/128 line. They want the exact opposite. 8 bit CPU instead of a 16 bit one... weird.
It's all preference though, and I don't see the point in debating it any further. SuperGrafx just needed some sort of 16 bit CPU. It's kind of apparent that the 6280 wasn't powerful enough to deal with everything well.
EDIT: added some C64 nonsense.
Not really debating so much as listing our wishes/wants of what the console should have came with
I think the easiest solution for a 16bit upgrade is to make the 6280 just like the 65816 in the register extension department. You have a flag that sets whether the bus and regs are 8bit, or 16bit. In 16bit mode, everything is extended. A, X, and Y are 16bit. PC is 32bit. Bus is 16bit. All the instructions are the same, just wider regs. D7/D6 flag logic would be extended to D15/D14, etc. If they really wanted to be cheap, they could keep the 8bit data bus like the 65816 does (but no need to multiplex the address bus since the 6280 already has a much bigger address line set than the 6502 and 65c02). But there's nothing stopping someone from just putting a cpu on the hucard just like SNES did. If SNES did it, then it's fair game. Same for my wish for extra two DMA DAC channels. The hucard slot has the audio line in, and the channels would be fine for mono (I'm was thinking along the lines of bass instruments and drumkits - they way some CD games to do chip music use the ADPCM channel for this. Fiend Hunter sounds great ).
