PCEmon: a Serial Monitor / Debugger for the PC-Engine / Turbografx



This is a program that I coded up on a whim (1-week vacation, yay!) in order to make it easier to do hacking and other actual useful things on the PC-Engine.  It's not for sheer beginners, and you need a 5V RS-232 (or FTDI TTL) serial port and a terminal program on your PC to make any use of it.  However, it does provide almost full access to any part of the PC-Engine's hardware.

Some Main Features:

  • Back up BRAM (save-files) to your PC, edit them, save them back to the PC-Engine (finally!)
  • Upload your own code to RAM and run it.  Upload larger files to CD-RAM and run them.
  • Upload image data to VRAM for viewing on the actual hardware.
  • Freeze a game in progress and view its screen data or RAM.
  • Resume a frozen game as-is, or resume from an uploaded savestate.
  • Search for and Activate RAM-freezing trainers for cheating in games.
  • Hex dump or Binary dump any part of the PCE's address space.
  • Disassemble the program space.
  • Dump the contents of VRAM to your PC as a .PCX file.
  • PCEmon can run as a stand-alone ROM or be embedded in games (eg: CD System Card.)
  • isn't this enough?

Connection Method (more detail here):

As seen to the right, all that is needed are 3 wires to be connected between the PCE controller port and one type of serial port (either in the form of a 9-pin RS-232 connector, or a specialized TTL molex connector).  Do NOT use an old, high-voltage (+-15~25V) RS-232 serial port!  You'll need to check and reduce the voltage of your serial line, or get a USB-to-TTL(FTDI) cable.  This project will be done at your own risk. You'll need a good terminal program on your computer, for example, Tera Term or Terminal.  The former has all input/output in the same window, which is more natural for an interactive monitor program like PCEmon.


Some pretty complete instructions are on this separate page.


PCEmon v 1.27.4  Contains .PCE ROMs for flash carts and ISO for burning onto a CD.  Source code is also included.

try connecting test leads at first
make an adaptor later
the view on-screen
a hex dump (of backup RAM)
uploaded a ROM directly to Super CD RAM
stop CD games at any time and view VRAM
download (V)RAM and re-upload later

©2015 Chris Covell.  Please send comments or feature requests here!