ReverendGumby, a core developer for MiSTer FPGA, has announced the completion of a significant update to the Super Cassette Vision core, following an in-depth reverse-engineering of the Epoch TV-1 video chip. This work, detailed in ‘doc/epochtv1.txt’, involved creating numerous test ROMs to precisely measure timing and behavior.
The core now boasts a highly accurate emulation of the original hardware’s rendering process. It successfully reproduces VRAM (sprite pattern) bus address patterns and even replicates specific graphical glitches observed on the original console, such as sprites dropping out when the CPU accesses VRAM during rendering.
As a result, all known display issues have been resolved. A new OSD menu option has also been added to mask the overscan region, improving the visual experience for scrolling games. This option, which now defaults to “large”, helps hide the edges of the display that would have been obscured by an old television bezel. This update marks a major achievement in preserving the Super Cassette Vision’s authentic visual behavior.
You can grab this latest version of the core, simply by running Update All.