Thanks for the unexpected link! Well, some info & pics then:
PCEmon is an RS232/TTL debugging tool for hackers/developers, but it also has some useful features for non-technical people as well. Some 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.
* Freeze a game in progress and view its screen data or RAM.
* Upload image data to VRAM for viewing on the actual hardware.
* Hex dump or Binary dump any part of the PCE's address space.
* Upload data to any part of the PCE's address space.
* PCEmon can run as a stand-alone ROM or be embedded in games (eg: CD System Card.)
* Dump the current screen as a .PCX image.
* Disassemble any part of memory.
Connections:
** USER BEWARE ** about using a high-voltage RS-232 connection.