I found an ICD Display enhancer (flicker fixer) on eBay some time ago. To install, I removed the Denise chip from my A500, and replaced it with the ICD board. The board has a 9 pin connector attached that you can connect to a PC monitor direct.
The results are stunning, in Interlace mode while connected to a VGA monitor, but note the flicker fixer does not work on Commodore 1084 monitors, as the board simply passes through the 15 pin (RGB) connector unmodified.
