Multicomp Cyclone II-B

Portions of the hardware and designs on this page are based on Grant Searle's original work, which was published with the following license:

“By downloading these files you must agree to the following: The original copyright owners of ROM contents are respectfully acknowledged. Use of the contents of any file within your own projects is permitted freely, but any publishing of material containing whole or part of any file distributed here, or derived from the work that I have done here will contain an acknowledgement back to myself, Grant Searle, and a link back to this page. Any file published or distributed that contains all or part of any file from this page must be made available free of charge.” -, retrieved 12/14/15.


cyclone_ii_b_built.jpgThe Multicomp Cyclone II-B (v1.09) is a motherboard which provides peripheral connectivity for a Cyclone II FPGA development board commonly available on eBay. The board was designed by James Moxham and Max Scane and provides connectivity for the following peripherals:

  • VGA Screen with PS/2 Keyboard interface
  • Two RS-232 serial ports with DE-9F connectors
  • SD Card connector
  • Two RAM sockets to support up to 1 MB of RAM.
  • Unused signal breakout and prototyping area
  • DC Jack for 5 Volt power input

Due to the header installation on the Cyclone II module, the module is required to be mounted inverted onto the motherboard.

Z80 Emulation Features

The Z80 Emulation VHDL code is based on Grant Searle's original Multicomp which has been extended to support additional peripherals and features

The VHDL code includes the following enhanced features:

  • Memory Management Unit supporting up to 1MB of physical RAM with 16KB pages
  • Fixed Baud-rate for all serial ports
  • 20 ms interrupt generator

These features are supported in the ROM-MJS Enhanced Monitor



FilenameFilesizeLast modified
cyclone-ii-b-schematic.pdf54.2 KiB2016/01/03 23:13

Z80 Emulation Code

FilenameFilesizeLast modified
multicomp-_z80-cycloneiib-pof.zip85.8 KiB2016/01/04 00:45
boards/sbc/multicomp/cycloneii-b/start.txt · Last modified: 2016/01/04 00:49 by mscane
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