So recently, I've been showcasing a lot of monitors I've made. Like the bomb monitor and high jump, and more recently, the spike behavior monitor. Today I'll teach you how to add them, but only the high jump and spike behavior boxes, because the bomb item was based off of MarkeyJester's "Destroy All Enemies on Screen" guide, found in the archived tutorials. Note: This isn't a copy and paste guide, the high jump and spike behavior monitors both use unused RAM addresses, however I don't want to assume what RAM addresses you want to use. And if I used ($FFFFFFF9).w, like some extra character guides, it could interfere. So instead look here for unused RAM addresses: http://info.sonicretro.org/SCHG:Sonic_the_Hedgehog_(16-bit)/RAM_Editing So whenever I use "($FFFFXXXX).w" or "($FFFFYYYY).w" replace it with whatever 2 RAM addresses you decided to use. This guide targets the Hivebrain 2005 disassembly, but could easily be ported to the GitHub disassembly. Anyways, let's begin! Step 1: Art This is really the only part I'm fully doing for you. Go and download this file; http://www.mediafire.com/file/188c1nq60kcu1u0/monitors.bin/file And replace it with the one in the artnem folder of your disassembly. And that's pretty much step 1 done. You could go into a level editor and place them down to see how they look, they'll still act the same though, and that's where step 2 comes in! Step 2: Monitors In sonic1.asm, go to "Obj2E:" and scroll down until you see this: Code: Obj2E_ChkS: cmpi.b #7,d0 ; does monitor contain 'S' bne.s Obj2E_ChkEnd nop Obj2E_ChkEnd: rts ; 'S' and goggles monitors do nothing This isn't what we want, so instead replace it with this: Code: Obj2E_ChkSpike: cmpi.b #7,d0 ; does monitor contain Spike? bne.s Obj2E_ChkHighJump tst.b ($FFFFXXXX).w ;Check if spike flag is inactive. beq.s Spike_Enable ;If so branch to activate it Spike_Disable: clr.b ($FFFFXXXX).w ;Turn off spike flag move.w #$A6,d0 jmp PlaySound ; play spike sound beq.s Obj2E_ChkHighJump Spike_Enable: move.b #$1,($FFFFXXXX).w ;Turn on spike flag move.w #$CD,d0 jmp PlaySound ; play clink sound You now have the code to make the monitor switch between an "on" and an "off" state. If you try building you'll get a few errors, 2 undefined errors, these are easy to fix. And lead into the next part of the guide. I'll teach you how to fix these real quick. Go to "Obj2E_ChkRings:" and find this line: Code: bne.s Obj2E_ChkS Simply replace the branch location to Obj2E_ChkSpike. Now we add our next monitor to fix the second undefined error. Below the Spike_Enable: routine, insert this Code: Obj2E_ChkHighJump: cmpi.b #8,d0 ;Does monitor contain high jump? bne.s Obj2E_ChkEnd move.b #$1,($FFFFYYYY).w ;Enable High Jump flag move.w #$CC,d0 jmp PlaySound ; play spring sound Try building now and everything will be fine, you can even go ahead and place them into a level. They now do something! Internally that is, nothing will take place except for a noise. Which leads nicely into step 3! Step 3: Actual Code Now you got the monitors working, you just need to make the code actually do something, first we'll start with the spike behavior monitor, as it's the easiest of the 2. All you need to do is to go to "Obj36_Hurt:" and replace everything before "move.l a0,-(sp)" with Code: tst.b ($FFFFFE2D).w ; is Sonic invincible? bne.s Obj36_Display ; if yes, branch cmpi.b #$1,($FFFFXXXX).w ; was the Spike Behavior enabled bne.s Obj36_HurtContinue ; if yes, branch tst.w ($FFFFD030).w ; is Sonic invulnerable? (Spike Behavior check) bne.s Obj36_Display ; if yes, branch Obj36_HurtContinue: That's all the code needed for the spike monitor, feel free to test it out! Now to add the high jump! Go to "Sonic_Jump:" and before "move.w #$680,d2" add these 2 lines: Code: cmpi.b #$1,($FFFFYYYY).w beq.s High_Jump And after the "move.w #$380,d2", but before "loc_1341C:" insert this: Code: beq.s loc_1341C High_Jump: move.w #$9C0,d2 ;Sonic's new jump height btst #6,$22(a0) beq.s loc_1341C move.w #$380,d2 Feel free to modify "move.w #$9C0,d2" for different heights. Now that's just about everything, except there's no way to deactivate the high jump, so lets do that, we'll make it so Sonic loses the high jump after getting hurt. Go to "HurtSonic:" you should see this: Code: HurtSonic: tst.b ($FFFFFE2C).w ; does Sonic have a shield? bne.s Hurt_Shield ; if yes, branch tst.w ($FFFFFE20).w ; does Sonic have any rings? beq.w Hurt_NoRings ; if not, branch jsr SingleObjLoad bne.s Hurt_Shield move.b #$37,0(a1) ; load bouncing multi rings object move.w 8(a0),8(a1) move.w $C(a0),$C(a1) In between the label and the first command insert these lines: Code: cmpi.b #$01,($FFFFYYYY).w ;Check if Sonic has the high jump beq.s Hurt_High Now below "Hurt_Shield:" and before "Hurt_Reverse:" insert this: Code: Hurt_High: clr.b ($FFFFYYYY).w ; remove high jump move.b #4,$24(a0) bsr.w Sonic_ResetOnFloor bset #1,$22(a0) move.w #-$400,$12(a0) ; make Sonic bounce away from the object move.w #-$200,$10(a0) btst #6,$22(a0) beq.s Hurt_Reverse move.w #-$200,$12(a0) move.w #-$100,$10(a0) There's one last thing to do, you don't want these to come with you into the next level, so this part is easy. Go to "Obj0D_Touch:" and before "locret_EBBA:" place these lines: Code: clr.b ($FFFFXXXX).w ;Clear Spike flag clr.b ($FFFFYYYY).w ;Clear high jump flag Now, go to "Obj3E_Switched:" and after Code: clr.b ($FFFFFE1E).w ; stop time counter clr.b ($FFFFF7AA).w ; lock screen position move.b #1,($FFFFF7CC).w ; lock controls move.w #$800,($FFFFF602).w ; make Sonic run to the right Insert the same code that you placed above "locret_EBBA:" Congrats! You now have 2 new monitors, that can let you jump 1.5 times higher and enable/disable the Sonic 1 spike behavior. Enjoy! And thanks for reading my first guide. If there's any errors I made, please notify me.