That reminds me of arcade games of the early 90s. So that is a decent job making an arcade quality game on a microcomputer (expensive one sure... but still not a dedicated console).

Haha. Thanks man. I dimly remember it took some messing with the arm assembly to get the scrolling fast enough to make the v-sync. And also that we used the hardware mouse pointer sprite to draw the player's spaceship, to get an extra couple of colours. Good times!