Retro Game Mechanics Explained
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rgmechex.com
Retro Game Mechanics Explained
@rgmechex.com
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A YouTube channel about video games & programming.
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Watch out, in the dark you might find a bug!
Subspace and the entirety of the Super Mario Bros. 2 level format explained in an upcoming video, available now for Patreon supporters and YouTube channel members!

patreon.rgmechex.com
May 7, 2025 at 2:02 AM
rgmechex.com
You can make it through all of world 1 of Super Mario Bros. 2 without beating a single boss, but you need some clever tricks to make it happen. New video soon, and available now for channel members and patrons!

patreon.rgmechex.com
January 15, 2025 at 9:09 PM
rgmechex.com
GCC Developer Steve Golson left a few comments on the recent video! He actually looked into an older version of the source code to see what exactly happened, and it looks like the code worked as intended at first, but was modified and broke during later development!
@13:46 Yes, it was just an error! I disassembled the earliest version of code I have (this is actually Crazy Otto). It shows the correct patch for all four monsters: 2745: 2A 0A 4D ld hl,($4D0A) 2748: 3A 2C 4D ld a,($4D2C) 274B: CD 2F 3F call $3F2F 274E: CD 66 29 call $2966 277B: 2A 0C 4D ld hl,($4D0C) 277E: 3A 2D 4D ld a,($4D2D) 2781: CD 2F 3F call $3F2F 2784: CD 66 29 call $2966 27B8: 2A 0E 4D ld hl,($4D0E) 27BB: 3A 2E 4D ld a,($4D2E) 27BE: CD 2F 3F call $3F2F 27C1: CD 66 29 call $2966 2800: 2A 10 4D ld hl,($4D10) 2803: 3A 2F 4D ld a,($4D2F) 2806: CD 2F 3F call $3F2F 2809: CD 66 29 call $2966 Note they all have the same CALL $3F2F. So originally we had it working, all four monsters random, and then we screwed up INKY and SUE when we adjusted the patch code to align with 8-byte boundaries. Ok that is seriously depressing. A bug report for work we did in November 1981, 43 years ago.
November 5, 2024 at 5:49 AM
rgmechex.com
I did end up making that followup video about Ms. Pac-Man and why I think Inky and Sue were not made to move randomly at the start of each level. There's a bunch of stuff to learn and explain about arcade hardware!

Available to watch now on Patreon! patreon.rgmechex.com

#rgme #pacman #mspacman
A diagram of a circuit board with a few of the integrated circuit chips highlighted in red. "Early access on Patreon!"
November 3, 2024 at 12:20 AM