I am building a portable 65c02-based computer that might serve as a useful tool in addition to what I will learn in the process.

All code and hardware is available at https://github.com/snorklerjoe/useful6502.

Here is the rundown of my goals:

• 65c02 processor with surrounding logic to provide some additional functionality:
  • User/kernel execution modes
  • Protected memory
  • Bank-switched application memory (up to 48kiB memory per process)
• PIC16 peripheral coprocessor, DMA interface through dual-port SRAM
  • PIC-orchestrated bootloading through the dual-port SRAM
  • SD card interface
• PS/2 keyboard interface and character LCD(s) for primary user interface
• Software
  • Pre-emptive multitasking 
  • Basic socket-like FIFO queues
  • Trap/syscalls through BRK instruction
  • FAT32 filesystem support
  • Basic UNIX-like utilities
  • Custom libc for cc65 to cross-compile applications

The schematic is available here.