The F256 Jr is a 65C02 based system that includes the following features:

512K of Shared System & Video RAM (256k on the Rev A)
256k of flash
256k of cartridge ram/rom
TinyVICKY Graphic Chip (CFP9599)
1x Simple 3-wire UART (RS-232 Port, Feather ESP8266 wifi, or Feather MIDI)
2x Atari Style Joystick Ports, 1x DB9 to interface to NES/SNES Adapter (For Rev B Only)
1x IEC Port to interface to Commodore Drives
2x Internal PSG Sound Chip
2x External SID Sockets

Hardware Setup

Kernels

There are two kernels for the Jr.