First release of ZSNES sources

zsnes/src/dos/gppro.asm

@@ -0,0 +1,156 @@
+;Copyright (C) 1997-2001 ZSNES Team ( zsknight@zsnes.com / _demo_@zsnes.com )
+;
+;This program is free software; you can redistribute it and/or
+;modify it under the terms of the GNU General Public License
+;as published by the Free Software Foundation; either
+;version 2 of the License, or (at your option) any later
+;version.
+;
+;This program is distributed in the hope that it will be useful,
+;but WITHOUT ANY WARRANTY; without even the implied warranty of
+;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;GNU General Public License for more details.
+;
+;You should have received a copy of the GNU General Public License
+;along with this program; if not, write to the Free Software
+;Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+%include "macros.mac"
+
+section .data
+sample times 60 db 0
+clock_mask db 0
+data_mask db 0
+
+section .text
+
+NEWSYM read_gpp
+   push ebx
+   push ecx
+   push edx
+   push edi
+   push esi
+
+   cmp al,0
+   jne GPP_L14
+   mov byte [clock_mask],0x10
+   mov byte [data_mask],0x20
+   jmp GPP_L15
+GPP_L14:
+   mov byte [clock_mask],0x40
+   mov byte [data_mask],0x80
+GPP_L15:
+
+
+   xor ebx,ebx
+   xor edi,edi
+
+   cli
+   in al,dx
+   mov ah,al
+
+GPP_L4:
+   xor ecx,ecx
+GPP_L0:
+   nop
+   nop
+   nop
+   nop
+   nop
+   nop
+   in al,dx
+   cmp al,ah
+   jne GPP_L1
+   inc ecx
+   cmp ecx,255
+   jl GPP_L0
+GPP_L1:
+   cmp ecx,255
+   je near GPP_ERR
+
+   test [clock_mask],ah
+   jz GPP_L2
+   test [clock_mask],al
+   jnz GPP_L2
+
+   test [data_mask],al
+   jz GPP_L3
+   mov byte [sample+edi],1
+   jmp GPP_L12
+GPP_L3:
+   mov byte [sample+edi],0
+GPP_L12:
+   inc edi
+
+GPP_L2:
+   mov ah,al
+   cmp ebx,200
+   je GPP_L13
+   inc ebx
+   cmp edi,50
+   jl GPP_L4
+
+GPP_L13:
+   sti
+   xor ecx,ecx
+   mov esi,1
+GPP_L7:
+   cmp byte [sample+esi],1
+   jg GPP_ERR
+   jne GPP_L6
+   inc ecx
+   jmp GPP_L5
+GPP_L6:
+   xor ecx,ecx
+
+GPP_L5:
+   cmp ecx,5
+   je GPP_L8
+   cmp esi,edi
+   je GPP_L8
+   inc esi
+   jmp GPP_L7
+
+GPP_L8:
+   cmp ecx,5
+   jne GPP_ERR
+   add esi,2
+   xor eax,eax
+   xor ebx,ebx
+   xor ecx,ecx
+   xor edx,edx
+
+GPP_L10:
+   inc ecx
+   cmp ecx,5
+   jne GPP_L11
+   mov ecx,1
+   inc esi
+GPP_L11:
+   mov dl,[sample+esi]
+   or eax,edx
+   shl eax,1
+   cmp ebx,13
+   je GPP_L9
+   inc ebx
+   inc esi
+   jmp GPP_L10
+
+GPP_L9:
+   pop esi
+   pop edi
+   pop edx
+   pop ecx
+   pop ebx
+   ret
+
+GPP_ERR:
+   sti
+   pop esi
+   pop edi
+   pop edx
+   pop ecx
+   pop ebx
+   mov eax,1
+   ret
+