VDC Soft-Sprite Demo

[Goodwell]

Here's a small, interactive demo that allows you to move a softsprite across a screen in 160x100 resolution (64 kB VRAM required).

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Use keys IJKL to move the ghost, X exits the program.
You can also list the sourcecode, which shows that the main loop is a regular basic program.

This uses the VDC-Basic extension which focuses on leveraging on the hardware capabilities of the VDC-Chip (block copy and block fill).
In 160x100, one byte holds two pixels.
Fully transparent bytes are skipped from block copy.
Bytes with one transparent pixel require a slow OR operation.

Still, drawing the softsprite only takes about 2 jiffies at 2 MHz.
This is using double buffering, so there's no flicker.

Looking at this, I think the C128 could have been capable of running DOS ports that never made it to the C64. Or ports that really were beyond the C64's strengths (eg Ultima VI)

You can find more information about VDC-Basic here: https://github.com/the8bittheory/vdc-basic