Are you planning to develop for revival of never released Commodore 65, http://mega65.org/?
No, but something a bit similar I guess... I am the creator and main developer of
Hacker's Edge, a multiplayer online hacking simulation game. The game uses a 65c02 Virtual Machine/Emulator to run all the virtual in-game computer systems, and most of the game is going to need to be programmed in 65c02. So far I wrote a pretty primitive operating system in 65c02 Assembly using the ca65 assembler, and cc65 is also able to target my in-game virtual machines. However, I very much prefer the Pascal language over the C language, which is why I was asking about how easy it can be to port FPC to target the 6502 with a custom memory map and program load addresses. Getting cc65 to work was very easy, as it has a fully working clib made in 6502 assembly, I only needed to update the crt0.s(C startup code), and a couple machine specific function calls like standard input/output, and it was able to compile code. However, I do understand that the FPC compiler isn't aware of 6502 whatsoever. I do see that AVR is supported, so it doesn't sound impossible to do, if an AVR target is possible, then I don't see why a 6502 target shouldn't be.
Another interesting advantage of supporting 6502 is being able to target even more Nintendo consoles.
I see Wii, NDS, and GBA are all supported targets. However, Nintendo's most iconic system, the Nintendo Entertainment System is absent as a FPC target. Adding 6502 code generation support will invite the NES along for the FreePascal ride as well. Although GBA/NDS are subsets of ARM, and Wii is a subset of the PPC targets... FreePascal could be the go-to language for targetting every single Nintendo platform.