Andy Toone's VideoBeast FPGA-Based Coprocessor Offers "Monster Graphics" for Eight-Bit Retro Systems

Vintage computing enthusiast Andy Toone has designed a "monster graphics" coprocessor for eight-bit microcomputers, offering 512 colors, sprite handling, widescreen resolutions, and 1MB of video RAM: the VideoBeast.

"Timing is unpredictable, the display state is opaque and functions are often limited to the precise use case the firmware was designed for," Toone explains of the issues with trying to handle video on resource-limited eight-bit machines. "It's not surprising many developers miss the purity of classic video display processors. VideoBeast is intended to provide that purity. It behaves like an old-school memory mapped display whilst providing the powerful compositing features of 2D arcade boards, 1MB of video ram and modern display resolutions."

The Video Beast itself is a compact castellated board roughly the size of a Raspberry Pi Pico but hosting a field-programmable gate array (FPGA) which acts as a video processor. Originally, the project began life as a spin-off of Toone's MicroBeast, an all-in-one Zilog Z80-based eight-bit computer kit-in-a-box, as a means of expanding the on-board character display to support external monitors — but, Toone explains, it's host-agnostic and designed to work with almost any eight-bit microcomputer new or old.

"VideoBeast should work with any system that can write to 4,8 or 16k static RAM chips. It imposes no timing restrictions on the host computer, other than an estimated 70ns access time," Toone explains. "Most importantly, the hardware is designed to be simple to program yet deliver usable power for 8-bit systems. VideoBeast is designed to recreate the power of a discrete logic video card, but in a tiny form factor and at a fraction of the cost."

Preliminary specifications for the board have it offering up to six independently positionable layers chosen from four layer types: text with four fonts and a choice of 16 colors from a palette of 512; bitmap, with 16 or 256 color palettes and full transparency; tile, offering a 16-color 8×8 tilemap with full scrolling; and sprite, with up to 96 16×16 sprites with 16 colors chosen from 16 palettes. These can be rendered at a range of resolutions, from 320×240 up to a widescreen 848×480 — and there's even an SD Card interface for good measure.

"The hardware is designed to be simple to program yet deliver usable power for 8-bit systems," Toone claims. "This is not about absolute resolution or color depth — both of which can overwhelm host processors. Instead, multiple independent text, tile, bitmap and sprite layers can be manipulated through a small register set."

"The large video RAM means that a thousand sprite patterns, or four thousand tiles, can be pre-loaded, as well as four software fonts and a number of full-screen bitmaps," Toone continues. "These can then be efficiently positioned on screen with all the conveniences of transparency, double buffering, raster effects and scan-line interrupts."

More information on the device is available on the Feersum Technology website; units will be offered first to MicroBeast owners, Toone has said, with a larger production run to follow for general availability; pricing has not yet been confirmed.