SCHG How-to:Port Sonic 2 Final Sound Driver to Sonic 1

Many have proven that the Sonic1 driver can obviously be put into Sonic2, but whbout the reverse?. Well, the reverse makes a few hacks easier, but I would prefer the sonic3 driver for its rich and diverse and effects and music. I guess it is all about personal choice. One advantage with this driver over the s3 one is that you do not have to worry about where you put things, the driver comes from disasm2007 and this guide uses a disasm2005 sonic1, which are very close to each other.

Overview

There are a lot of things that need to change before we can use this:

• First off we need to insert the disasm2007 macros, this makes it relatively easier to work with.
• Next we will have to update the vertical and horizontal interrupts. Every time the z80 is stopped, we need to call the sound driver input routine.
• We also need the sound driver input routine as well, obviously.
• we also need to alter the play sound routines, sonic2 sound routines are needed instead of sonic1 ones (pause and unpause included)
• all the places a sound is played need to be updated to play the correct sounds
• the level select and debug need fixing.
• sonic2 build tools need to be put in place.

importing disasm2007 macros

If we did not add the macros then we would have to expand them instead and that makes our work a lot harder. So let insert the macros: first create a new file called "s2.macrosetup.asm" and put this in it: <asm>

padding off ; we don't want AS padding out dc.b instructions listing off ; we don't need to generate anything for a listing file supmode on ; we don't need warnings about privileged instructions

paddingSoFar set 0

128 = 80h = z80, 32988 = 80DCh = z80unDoC

notZ80 function cpu,(cpu<>128)&&(cpu<>32988)

make org safer (impossible to overwrite previously assembled bytes) and count padding

and also make it work in Z80 code without creating a new segment

org macro address if notZ80(MOMCPU) if address < * if assembleZ80SoundDriver error "too much stuff before org $\{address} ($\{(*-address)} bytes)" else error "too much stuff before org $\{address} ($\{(*-address)} bytes) ... try setting assembleZ80SoundDriver=1 in the asm file" endif elseif address > * paddingSoFar set paddingSoFar + address - * !org address endif else if address < $ error "too much stuff before org 0\{address}h (0\{($-address)}h bytes)" else while address > $ db 0 endm endif endif

   endm

define the cnop pseudo-instruction

cnop macro offset,alignment if notZ80(MOMCPU) org (*-1+(alignment)-((*-1+(-(offset)))#(alignment))) else org ($-1+(alignment)-(($-1+(-(offset)))#(alignment))) endif

   endm

redefine align in terms of cnop, for the padding counter

align macro alignment cnop 0,alignment endm

define the even pseudo-instruction

even macro if notZ80(MOMCPU) if (*)&1 paddingSoFar set paddingSoFar+1 dc.b 0 ;ds.b 1 endif else if ($)&1 db 0 endif endif

   endm

make ds work in Z80 code without creating a new segment

ds macro if notZ80(MOMCPU) !ds.ATTRIBUTE ALLARGS else rept ALLARGS db 0 endm endif

  endm

 if TRUE

define a trace macro

lets you easily check what address a location in this disassembly assembles to

if used in Z80 code, the displayed PC will be relative to the start of Z80 RAM

trace macro optionalMessageWithoutQuotes

   if MOMPASS=1

if notZ80(MOMCPU) if ("ALLARGS"<>"") message "#\{tracenum/1.0}: line=\{MOMLINE/1.0} PC=$\{*} msg=ALLARGS" else message "#\{tracenum/1.0}: line=\{MOMLINE/1.0} PC=$\{*}" endif else if ("ALLARGS"<>"") message "#\{tracenum/1.0}: line=\{MOMLINE/1.0} PC=\{$}h msg=ALLARGS" else message "#\{tracenum/1.0}: line=\{MOMLINE/1.0} PC=\{$}h" endif endif tracenum := (tracenum+1)

   endif
  endm
 else

trace macro endm

 endif

tracenum := 0

   if zeroOffsetOptimization=0
   ; disable a space optimization in AS so we can build a bit-perfect rom
   ; (the hard way, but it requires no modification of AS itself)

1-arg instruction that's self-patching to remove 0-offset optimization

insn1op macro oper,x if substr("x",0,2)<>"0(" !oper x else !oper 1+x !org *-1 !dc.b 0 endif endm

2-arg instruction that's self-patching to remove 0-offset optimization

insn2op macro oper,x,y if substr("x",0,2)<>"0(" if substr("y",0,2)<>"0(" !oper x,y else !oper x,1+y !org *-1 !dc.b 0 endif else if substr("y",0,1)<>"D" if substr("y",0,2)<>"0(" !oper 1+x,y !org *-3 !dc.b 0 !org *+2 else !oper 1+x,1+y !org *-3 !dc.b 0 !org *+1 !dc.b 0 endif else !oper 1+x,y !org *-1 !dc.b 0 endif endif endm

; instructions that were used with 0(a#) syntax ; defined to assemble as they originally did _move macro insn2op move.ATTRIBUTE, ALLARGS endm _add macro insn2op add.ATTRIBUTE, ALLARGS endm _addq macro insn2op addq.ATTRIBUTE, ALLARGS endm _cmp macro insn2op cmp.ATTRIBUTE, ALLARGS endm _cmpi macro insn2op cmpi.ATTRIBUTE, ALLARGS endm _clr macro insn1op clr.ATTRIBUTE, ALLARGS endm _tst macro insn1op tst.ATTRIBUTE, ALLARGS endm

else

; regular meaning to the assembler; better but unlike original _move macro !move.ATTRIBUTE ALLARGS endm _add macro !add.ATTRIBUTE ALLARGS endm _addq macro !addq.ATTRIBUTE ALLARGS endm _cmp macro !cmp.ATTRIBUTE ALLARGS endm _cmpi macro !cmpi.ATTRIBUTE ALLARGS endm _clr macro !clr.ATTRIBUTE ALLARGS endm _tst macro !tst.ATTRIBUTE ALLARGS endm

   endif

</asm>