beating IsDebuggerPresent for my unpacker

; debug api test
;================
	mov eax,cs
	cmp ax,0FFh
	setg Is9x
	.if Is9x
		;; structures are documented by EliCZ
		mov eax,fs:[20h];TIB.DebugContext
		test eax,eax
		setnz al
		or Detected,al
		mov ebx,fs:[30h];TIB.pParentPDB
		mov eax,[ebx+20h];[ebx].PDB.flags
		and eax,1;fDebugSingle equ 1
		or Detected,al
		mov eax,[ebx+54h];[ebx].PDB.DebuggeeCB  :IsDebuggerPresent
		test eax,eax
		setnz al
		or Detected,al
	.else
		;; ddk
		mov eax,fs:[30h];TEB.pPEB         ; pointer to PEB
		movzx eax,byte ptr [eax+2];[eax].PEB.BeingDebugged   :IsDebuggerPresent
		or Detected,al
	.endif

you can't patch DebugContext in 9x
while BeingDebugged you can (upb's 1st post)

debug api in 9x suck
for example try to trace (single step)
not esp
not esp
*crash*

forget about 9x, support only NT (it's only a unpacker, unpacked exe must work on both)