[pjc50]

Hardware sprite systems such as the Atari 2600 did not have any VRAM.

The 2600 had 128 bytes of RAM. It supported a small number of fixed sprites. These were implemented by setting the X and Y coordinates in registers; as the scan-out of pixels passed that point, it would switch to drawing in the sprite color if a pixel was present at the bit position in the sprite.

It was possible to count how far down the screen the scan-out had got and re-use a sprite that had already been used above, to get more than the allowed number of sprites.

See the book Racing the beam for a lot more detail.

Edit: however this WAS a VRAM system. Seems to have added a dedicated shift helper but is still using blitting to VRAM. See "game timing" section of OP page.