Commodore Amiga
Production-ready patterns for Commodore Amiga development
Rendering
7 patternsBlitter Copy
Move a rectangular block of graphics with the Amiga's blitter instead of the CPU — set four registers, write BLTSIZE, and Agnus streams the copy while the processor does something else.
Blitter Line Draw
The blitter isn't only a copier — in line mode it plots a Bresenham line in hardware, one pixel at a time, straight into a bitplane. Feed it endpoints and an octant; it draws the line while the CPU moves on.
Cookie-Cut Blit
Draw a shaped, transparent object over the background using all four blitter channels — a mask decides pixel by pixel whether to keep the image or the scenery behind it. The heart of every Amiga bob.
Copper Colour Bars
Change the background colour at chosen scanlines from the copper list — no CPU, no interrupt, no jitter — to paint horizontal bars or a smooth vertical gradient the beam draws for you.
Copper List Basics
Build a copper list to set colours and sprite pointers. The foundation of all Amiga graphics programming.
Copper Split Screen
Have the copper reprogram the bitplane pointers part-way down the frame so the top and bottom of the screen show different bitmaps — a scrolling playfield above a rock-steady status panel, beam-locked and free.
Sprite Control Words
Calculate and update Amiga sprite control words from X/Y coordinates. Position sprites anywhere on screen.
Input
2 patternsAudio
3 patternsFour-Channel Music
Drive all four of Paula's channels from a note sequence, stepping the pattern on a timer interrupt and turning note numbers into periods — the skeleton of every Amiga tracker and MOD player.
One-Shot Samples
Play a sample once instead of looping, using Paula's channel interrupt to stop it after a single pass — the way sound effects fire, and the seed of tracker playback.
Playing a Sample
Point one of Paula's four audio channels at an 8-bit sample in chip RAM, set its pitch and volume, and let DMA play it — the foundation of all Amiga sound.