Project maintainers


Name: system09
Created: May 16, 2003
Updated: Jan 31, 2021
SVN Updated: Apr 9, 2021
SVN: Browse
Latest version: download (might take a bit to start...)
Statistics: View
Bugs: 9 reported / 7 solved
Star5you like it: star it!

Other project properties

Category:System on Chip
Development status:Stable
Additional info:
WishBone compliant: No
WishBone version: n/a
License: GPL


6809 System On a Chip that emulates the SWTPc 6809. It has been ported to a variety of FPGA boards including the XESS XSA-3S1000, BurchED B5-X300 and Digilent Spartan 3 Starter board. The System09 project page with revision history can be found at . System09 runs the Flex9 disk operating system for the 6809 which can be found at the Flex Users Group . The Flex disk operating system and most of the associated software has been placed in the public domain. The source code for Flex9 can be found in the CVS repository. I have included ROMs for the NOICE debugger for the 6309/6809.


- 6809 instruction compatible
- 6850 compatible ACIA/UART (57.6 KBaud)
- Hardware Trap Logic
- Dual 8 bit I/O port
- Simple timer
- 80 x 25 character Video Display with colour attributes
- Compact Flash interface
- PS/2 Keyboard Interface
- SYS09BUG Monitor ROM with Video driver
- Dynamic Address Translation supports up to 1Mbyte of RAM
- Fits in 300KGate Spartan IIe
- Uses Xilinx Block RAM for monitor ROM and VDU memory.
- Optional NOICE ROMs


  • Skeleton implementation on Digilent Zybo Z7-20 board (56k in BRAM, SBug ROM and serial console over Pmod RS232) using ISE 14.7.
  • Skeleton implementation on Digilent Atlys Spartan6 board (56k in BRAM, SBug ROM and serial console over usb2uart) using ISE 14.7.
  • Implemented on XESS XuLA-200 using ISE 12.4.
  • Implemented on Terasic DE1 board using Altera Quartus II.
  • Implemented on XESS XSA-3S1000 + XST-3.0 running Flex9 from IDE drive / CF card
  • Implemented on Digilent XC3S200 Starter Board with RAM disk
  • Implemented on BurchED B5-X300 FPGA Board running Flex9 from CF.
  • Limited Implementation on Digilent XC3S500E starter board using Block RAM.
  • Runs the SYS09BUG Monitor ROM with Video Display drivers.
  • Runs the Flex9 Disk operating system from RAM Disk, IDE Drive or Compact Flash
  • Also run NOICE Monitor for the 6809
  • Implemented with WebPack ISE 7.1i for upward compatibility.