#raster irqs · 6 posts

Effects built on stable raster interrupts and cycle-exact timing.

12 October 2026 Effects intermediate

Sprite Interleave

A gap-free carpet of sprites on the C64: no interleave against 16px and 20px interleave, badline timing, and fast sprite pointer updates.

11 October 2026 Engineering hard

How No Bounds hides loading on the C64: background loading with Sparkle, transitions that cover the disk, clean IRQ handovers and music sync.

Series: No Bounds

05 June 2023 Effects hard

The finite bobs part from No Bounds: a bob trail plotted into charsets over an AGSP-scrolled C64 background, restored behind it as it goes.

Series: No Bounds

01 June 2023 Engineering intermediate

Finding and fixing uneven music play calls in C64 demos, using VICE monitor traces to spot missed, doubled and drifting calls.

Series: No Bounds

13 April 2022 Effects intermediate

How the big animating Genesis Project sprite logo in Memento Mori works on the C64: a 20px interleaved sprite carpet and delta-blitted frames.

Series: Memento Mori

30 March 2022 Effects hard

How the huge swinging Memento Mori logo works on the C64: a packed charset logo over an x-expanded sprite layer, with interleaved IRQ code.

Series: Memento Mori