The VIC-20 has redefinable text characters. In normal text mode, the video chip fetches character definitions from ROM, but you can change a register so that it read them from RAM instead, making arbitrary 8x8 graphics possible for each character. And by using several such characters, you can build islands of bitmapped graphics. Just moving such islands of redefined characters around would make for jumpy movements (8 pixels at a time), and many less accomplished games do just that. This game achieves smooth pixel-by-pixel movement by dynamically redefining the character definitions for small movements (< 8 pixels) and moving entire character islands when the total movement reaches 8 pixels. It's a quite advanced technique, especially considering that it needs to handle arbitrary overlap between sprites, and do it within the very limited RAM of the unexpanded VIC-20 (it helps that it's a cartridge-based game, though, since code and static data can be left in ROM, leaving more RAM for graphics).
@@IoannisPafos It is official The story goes that HAL secured the rights to make Pac-Man for home computers from Namco themselves, releasing the game officially in Japan in 1981 Commodore then released the port overseas and renamed it to Jelly Monsters, well aware of the consequences and possibly without authorization from Namco Atari found out, and made Commodore get all copies of "Jelly Monsters" off the market
This is impressive work on a machine that has no bitmap graphics or hardware sprites, I wonder how the author of this pulled this off.
Thats true & i have no idea how but it is a fun game for sure.
@akira, thats because it was done by hal laboratory which developed some of the best games like revenge of the gator and smash bros. melee
The VIC-20 has redefinable text characters. In normal text mode, the video chip fetches character definitions from ROM, but you can change a register so that it read them from RAM instead, making arbitrary 8x8 graphics possible for each character. And by using several such characters, you can build islands of bitmapped graphics. Just moving such islands of redefined characters around would make for jumpy movements (8 pixels at a time), and many less accomplished games do just that. This game achieves smooth pixel-by-pixel movement by dynamically redefining the character definitions for small movements (< 8 pixels) and moving entire character islands when the total movement reaches 8 pixels. It's a quite advanced technique, especially considering that it needs to handle arbitrary overlap between sprites, and do it within the very limited RAM of the unexpanded VIC-20 (it helps that it's a cartridge-based game, though, since code and static data can be left in ROM, leaving more RAM for graphics).
Yes .. this is a cool version 👍
Wish I had this when i was a kid, i was stuck with cosmic cruncher
I wish i had parents but i probably would of traded them for Jelly Monsters Haha!
yo same even if I don’t have a VIC-20
This is pac-man not jelly monsters
No fooling you 😉
this version of pac man was named "jelly monsters".
@@IoannisPafos not in Japan! This is for all intents and purposes an official port of Pac-Man
@@martinefrensoquigomez7835 this version is NOT official. Namco and Atari didn't allow HAL Laboratory to make this version.
@@IoannisPafos It is official
The story goes that HAL secured the rights to make Pac-Man for home computers from Namco themselves, releasing the game officially in Japan in 1981
Commodore then released the port overseas and renamed it to Jelly Monsters, well aware of the consequences and possibly without authorization from Namco
Atari found out, and made Commodore get all copies of "Jelly Monsters" off the market