In this video I look at Commodore 64 Bubble Bobble and how its software sprite rendering works and demonstrate how the code can render extra sprites.

https://github.com/martinpiper/Debugg...

GMA disk loader:    • Disk fast load digital archeology - V...  

00:12 Introduction
00:29 Disk "Bleep load"
01:07 Memories
01:21 Looking for hardware sprites
01:32 ... and software sprites
02:38 More character masking
03:54 Starting to see dynamic characters
05:16 Two character sets!
05:48 Lots of hardware sprite frames
08:18 Memory write debug, for character sets
09:55 Using the machine code monitor
12:35 Backup screen data
14:15 Dynamic characters for each level
15:26 Collision data
18:18 Finding software sprite code
35:56 Finding frame, xpos and ypos tables
39:01 Rendering new sprites!
41:50 Technical summary