How to record demos

NOTE: THIS IS NOT COMPATIBLE WITH THE 6-PAD GUIDE


Requirements:

• Sonic 1 2005 disasm
  
• Hex editor
  

Instructions:

• In built.bat replace everything with this: ("pause" is optional)
  
  
  
  Code:

  @echo off
  
  asm68k /p /o ae- /e DemoRecord=0 sonic1.asm, s1built.bin
  
  fixheadr.exe s1built.bin
  
  pause

• Copy the file build.bat, rename to "build_demo.bat", and change "DemoRecord=0" to "DemoRecord=1"
  

In sonic1.asm:

• You will need to enable SRAM, go to "SRAMSupport:" replace:
  
  
  Code:

  SRAMSupport:    dc.l $20202020        ; change to $5241E020 to create    SRAM
          dc.l $20202020        ; SRAM start
          dc.l $20202020        ; SRAM end
  

  With this:
  
  
  Code:

                  dc.b "RA",$E8,$20
  		dc.l $200000
  		dc.l $203FFF
  

• Go to "PlayLevel:" and replace:
  
  
  Code:

          move.b    #$8,($FFFFF600).w ; set    screen mode to $08
  

  With this:
  
  
  Code:

      if DemoRecord=1
          move.b    #$8,($FFFFF600).w ; set    screen mode to $08
      else
          move.b    #$C,($FFFFF600).w ; set    screen mode to $0C (level)
      endif
  

• Now go to "Level_Demo", replace:
  
  
  Code:

  Level_Demo:
          move.b    1(a1),($FFFFF792).w ; load key press duration
          subq.b    #1,($FFFFF792).w ; subtract 1 from duration
  

  With this:
  
  
  Code:

  Level_Demo:
      if DemoRecord=0
          move.b    1(a1),($FFFFF792).w    ; load key press duration
          subq.b    #1,($FFFFF792).w    ; subtract 1 from duration
          bcc    Level_Demo_NullPress
          move.b    3(a1),($FFFFF792).w
          addq.w    #2,($FFFFF790).w
  Level_Demo_NullPress:
      endif
  

• Go to "MoveSonicInDemo" and replace everything until "MoveDemn" with this:
  
  
  Code:

  MoveSonicInDemo:
      if DemoRecord=0
          tst.w    ($FFFFFFF0).w    ; is demo mode on?
          bne.s    MoveDemo_On    ; if yes, branch
          rts
      endif
  
  ; ===========================================================================
  
  ; This is an unused subroutine for recording a demo
  
  MoveDemo_Record:
      ;    lea    ($80000).l,a1
          lea    ($200400).l,a1
          move.w    ($FFFFF790).w,d0
          adda.w    d0,a1
          move.b    ($FFFFF604).w,d0
          cmp.b    (a1),d0
          bne.s    loc_3FFA
          addq.b    #1,1(a1)
          cmpi.b    #$FF,1(a1)
          beq.s    loc_3FFA
          rts    
  ; ===========================================================================
  
  loc_3FFA:                ; XREF: MoveDemo_Record
          move.b    d0,2(a1)
          move.b    #0,3(a1)
          addq.w    #2,($FFFFF790).w
          andi.w    #$3FF,($FFFFF790).w
          rts    
  ; ===========================================================================
  

  (To fix the demo playback, use the FraGag's guide in Retro Here)
  
  
  
• Build the ROM with "build_demo.bat", Now start playing the level until you see the fadeout
  
• Open the Hex editor, and open s1built.srm, go to $400 (skip the first two $FF bytes)
  
• Copy the data until the end of the .srm file
  
• In the demodata folder, Open the Hex editor the respective demo level file, for example: if you recorded the demo in GHZ, open "i_ghz.bin"
  
• Delete everything from the demo file and paste the demo data from the .srm file, Then save
  
• Now build the ROM with "build.bat", and test the recorded demo
  
• If the demo plays correctly, Done. (and if not, try again)
  

 

I'm definitely using this guide. Really useful. Thanks for that, many people will be able to record demos... I've been waiting for thid about one year. Nice work =)

 

You have no idea on how it will be useful for me. Thank you very much! <_<

 

Wait... About half of this code isn't even needed. In No-Name I just removed a few RTS, and changed an adress and voila.

 

He made it so you can use demo recording depending on which build.bat you use but still only using one sonic1.asm.

 

Ah, I can just add an rts and disable demo recording?

 

Enabling demo recording is useless if you don't know how to use the output or where to find it (which is the SRAM in this case). DO you know how to do that with your rts only thing?

 

Yeah, I was the one that came up with the solution in the beginning, GenesisFan64 just made it more user friendly I suppose.

 

I don't see:



move.b #$8,($FFFFF600).w ; set screen mode to $08



anywhere near "PlayLevel:". All I see is something similar:



move.b #$C,($FFFFF600).w ; set screen mode to $0C (level)



Is this the same thing?


EDIT: Camera will not scroll down. I tried to record a demo of my new GHZ Layout I made in SonED2, but when I used the S-Tube, Sonic dies, demo ends. Who knows how to fix that camera bug?