Gameplay footage

A project log for GameTank 8-Bit Retroconsole

6502-powered game console with hardware-accelerated drawing

Clyde ShafferClyde Shaffer 12/12/2020 at 18:570 Comments

This is a few months ago, running a game on the v1 prototype. Note the color artifacts on high-contrast edges, and how faint the player character's hair is against the black background. These have subsequently been fixed by redesigning the video signal combiner circuit.

The game runs at a consistent 60 frames per second thanks to the blitter, which is capable of writing every pixel on the screen over 800 times per second if needed. It also runs independently of the CPU, which is free to perform other tasks during a draw operation. Thus it is very cheap to clear the screen and redraw a tilemap every frame, as well as draw movable objects on top. The blitter has a transparency mode which can skip zero-valued pixels, making it simple to draw animated characters to the framebuffer.