clarify PicoDrive's license

- PicoDrive was originally released by fDave with simple
  "free for non-commercial use / For commercial use, separate licencing
  terms must be obtained" license and I kept it in my releases.
- in 2011, fDave re-released his code (same that I used as base
  many years ago) dual licensed with GPLv2 and MAME licenses:
    https://code.google.com/p/cyclone68000/

Based on the above I now proclaim that the whole source code is licensed
under the MAME license as more elaborate form of "for non-commercial use".
If that raises any doubt, I announce that all my modifications (which
is the vast majority of code by now) is licensed under the MAME license,
as it reads in COPYING file in this commit.

This does not affect ym2612.c/sn76496.c that were MAME licensed already
from the beginning.

pico/cd/buffering.c

@@ -1,5 +1,10 @@
-// Buffering handling
-// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+/*
+ * Buffering handling
+ * (C) notaz, 2007,2008
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"
 

pico/cd/cell_map.c

@@ -1,5 +1,10 @@
-// Convert "cell arrange" address to normal address.
-// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+/*
+ * Convert "cell arrange" address to normal address.
+ * (C) notaz, 2008
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 // 64 x32 x16 x8 x4 x4
 static unsigned int cell_map(int celln)

pico/cd/cue.c

@@ -1,3 +1,10 @@
+/*
+ * cuefile handling
+ * (C) notaz, 2008
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

pico/cd/memory.c

@@ -1,5 +1,10 @@
-// Memory I/O handlers for Sega/Mega CD.
-// (c) Copyright 2007-2009, Grazvydas "notaz" Ignotas
+/*
+ * Memory I/O handlers for Sega/Mega CD.
+ * (C) notaz, 2007-2009
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"
 #include "../memory.h"

pico/cd/memory_arm.s

@@ -1,8 +1,10 @@
-@ vim:filetype=armasm
-
-@ Memory I/O handlers for Sega/Mega CD emulation
-@ (c) Copyright 2007-2009, Grazvydas "notaz" Ignotas
-
+@*
+@* Memory I/O handlers for Sega/Mega CD emulation
+@* (C) notaz, 2007-2009
+@*
+@* This work is licensed under the terms of MAME license.
+@* See COPYING file in the top-level directory.
+@*
 
 .equiv PCM_STEP_SHIFT, 11
 
@@ -734,3 +736,4 @@ m_s68k_write16_regs_spec:               @ special case
 
 .pool
 
+@ vim:filetype=armasm

pico/cd/misc.c

@@ -1,5 +1,10 @@
-// Some misc stuff
-// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+/*
+ * PicoDrive
+ * (C) notaz, 2007
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"
 

pico/cd/misc_arm.s

@@ -1,7 +1,10 @@
-@ vim:filetype=armasm
-
-@ Memory converters for different modes
-@ (c) Copyright 2007, Grazvydas "notaz" Ignotas
+@*
+@* Memory converters for different modes
+@* (C) notaz, 2007-2008
+@*
+@* This work is licensed under the terms of MAME license.
+@* See COPYING file in the top-level directory.
+@*
 
 
 @ r10 is tmp, io1 is lsb halfword, io2 is msb
@@ -73,4 +76,4 @@ _1Mto2M_loop:
 
     ldmfd   sp!,{r4-r11,pc}
 
-
+@ vim:filetype=armasm

pico/cd/pcm.c

@@ -1,6 +1,10 @@
-// Emulation routines for the RF5C164 PCM chip.
-// Based on Gens code by Stéphane Dallongeville
-// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+/*
+ * Emulation routines for the RF5C164 PCM chip
+ * (C) notaz, 2007
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"
 #include "pcm.h"

pico/cd/pico.c

@@ -1,5 +1,10 @@
-// (c) Copyright 2007 notaz, All rights reserved.
-
+/*
+ * PicoDrive
+ * (C) notaz, 2007
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"
 #include "../sound/ym2612.h"

pico/cd/pico_arm.s

@@ -1,12 +1,15 @@
-@ vim:filetype=armasm
+@*
+@* CPU scheduling code
+@* (C) notaz, 2007-2008
+@*
+@* This work is licensed under the terms of MAME license.
+@* See COPYING file in the top-level directory.
+@*
 
 @ SekRunPS runs PicoCpuCM68k and PicoCpuCS68k interleaved in steps of PS_STEP_M68K
 @ cycles. This is done without calling CycloneRun and jumping directly to
 @ Cyclone code to avoid pushing/popping all the registers every time.
 
-@ (c) Copyright 2007, Grazvydas "notaz" Ignotas
-@ All Rights Reserved
-
 
 .equiv PS_STEP_M68K, ((488<<16)/20) @ ~24
 
@@ -179,3 +182,4 @@ CycloneSpecial2:
   mov r5,#0
   bx r1
 
+@ vim:filetype=armasm

pico/cd/sek.c

@@ -1,5 +1,10 @@
-// (c) Copyright 2007 notaz, All rights reserved.
-
+/*
+ * PicoDrive
+ * (C) notaz, 2007
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 
 #include "../pico_int.h"