Sunday, October 15, 2017

SBTGA: SBTCVM's graphics adapter.


It happened.

SBTGA mode G0, 114x81 @ 3-trit RGB, (27 colors)
SBTCVM, for the longest time, has had no framebuffered displays. and while the 9x9 and 27x27 plotters have proved functional, the time has come.

SBTGA currently has a standby mode (default), and Graphics Mode 0 (G0, shown). While its indeed colorful, SBTGA has more features planned: such as formatted text modes, and a new, high-resolution plotter mode to replace the old 9x9 and 27x27 plotters that have proven quite useful.


Under the hood, SBTGA is SBTCVM's first complex IObus device, (unless you consider a basic psudo-random number generator or scratch memory, complex)
it works via a pointer address that points to a portion of Memory Bank A (the first memory bank), that tells SBTGA where its DMA-based framebuffer is. 

Naturally this lets programs have precomputed framebuffer memory ranges.In fact, this is the first job of the new MK2-GAT.py utility (GAT meaning Graphics Adapter Toolkit): To convert 114x81 binary images, to SBTGA Mode G0 framebuffer maps.

And while for the moment, SBTGA lacks even sprites, Its a definite start to a new chapter in SBTCVM's development.

1 comment:

  1. Yay! I love the framebuffer demos, they remind me of having fun with 8-bit computers. :)

    I'm finally running SBTCVM on a screen big enough for my old eyes. It's good, and all the extra UI bits are nice too.

    -- eekee

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