F256JR

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

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Kernels

There are two kernels for the Jr.

• The TinyCore MicroKernel
• OpenKERNAL

MicroKernel

The TinyCore MicroKernel comes installed by default. It is an advanced kernel with an integrated IP stack.

Flash blocks are available from both the kernel/dos github repo: https://github.com/ghackwrench/F256_Jr_Kernel_DOS

Flash blocks tested with the latest SuperBASIC may be found in the source/releases folder of the SuperBASIC project: https://github.com/paulscottrobson/superbasic

When using the MicroKernel, the dip switches act as follows:

* 8 - enable gamma color correction
* 7 - 640x480x60 if on, 640x400@70 if off.  Not presently implemented.
* 6 - Enable scanning of a CBM keyboard (F256-Jr); Sound expansion installed (F256-K)
* 5 - SIDS are installed
* 4 - SLIP enabled
* 3 - Serial description: If SLIP is enabled, ON implies WIFI mode; if SLIP is disabled, ON implies MIDI mode.
* 2 - Not yet assigned
* 1 - If ON, the kernel will auto-start the first program found in the first 64k 

OpenKERNAL

OpenKERNAL is a clean-room clone of the CBM KERNAL as described in the C64 documentation. It may be found here. Note that it is presently somewhat out of date, as the FPGA's keyboard and IEC interfaces have changed.

Hardware Setup

• Port pin-outs
• Adding a mouse port on early Rev B Boards

Documents

Hardware Setup

Ports and Connectors