Commit: 763a11a56ff57be184c7e6a19ab61205c86c3ffb - kmbasic2 (git)

BASIC compiler/interpreter for PIC32MX/MZ-80K

Commit MetaInfo

• Revision: 763a11a56ff57be184c7e6a19ab61205c86c3ffb (tree)
• Zeit: 2019-04-07 08:59:25
• Autor: Katsumi <kmorimatsu@sour...>
• Commiter: Katsumi

Log Message

Megalopa update for TIMER, INTERRUPT, and OPTION

Ändern Zusammenfassung

• modified: mips/megalopa/class.c
• modified: mips/megalopa/compiler.c
• modified: mips/megalopa/compiler.h
• modified: mips/megalopa/debug.c
• modified: mips/megalopa/envspecific.h
• modified: mips/megalopa/exception.c
• modified: mips/megalopa/file.c
• modified: mips/megalopa/function.c
• modified: mips/megalopa/globalvars.c
• modified: mips/megalopa/megalopa.mcp
• modified: mips/megalopa/music.c
• modified: mips/megalopa/reservednames.js
• modified: mips/megalopa/run.c
• modified: mips/megalopa/sharedfiles.js
• modified: mips/megalopa/statement.c
• add: mips/megalopa/timer.c
• modified: mips/megalopa/varname.c
• modified: mips/zoea/sharedfiles.js

Diff

--- a/mips/megalopa/class.c
+++ b/mips/megalopa/class.c
@@ -157,7 +157,8 @@ char* resolve_unresolved(int class){
 				break;
 			default:
 				return ERR_UNKNOWN;
-		}
	}
+		}
+	}
 	return 0;	
 }
 
@@ -194,6 +195,15 @@ char* update_class_info(int class){
 		cstruct[z+1]: public method pointer
 */
 
+/*
+	Object structure:
+		object[0]:   pointer to class structure
+		object[1]:   field value
+		...
+		object[n]:   field value
+		(according to class structure; public field(s) first, then private field(s))
+*/
+
 char* construct_class_structure(int class){
 	int* record;
 	int i;

--- a/mips/megalopa/compiler.c
+++ b/mips/megalopa/compiler.c
@@ -110,8 +110,9 @@ int nextCodeIs(char* str){
 	if (!strncmp(g_source+g_srcpos,str,len)) {
 		if ('A'<=str[len-1] && str[len-1]<='Z') {
 			// When the last character of str is alphabet, 
-			// the next character in source must be space, enter, or ':'.
-			if (0x20<g_source[g_srcpos+len] && g_source[g_srcpos+len]!=':') return 0;
+			// the next character in source must be space, enter, ',', or ':'.
+			if (0x20<g_source[g_srcpos+len] && 
+				g_source[g_srcpos+len]!=':' && g_source[g_srcpos+len]!=',') return 0;
 		}
 		// String matches in the current position in source.
 		g_srcpos+=len;
@@ -160,8 +161,10 @@ char* compile_line(void){
 			printstr(resolve_label(g_line));
 			return ERR_MULTIPLE_LABEL;
 		}
-		check_obj_space(1);
-		g_object[g_objpos++]=0x34160000|g_line; //ori         s6,zero,xxxx;
+		if (!g_nolinenum) {
+			check_obj_space(1);
+			g_object[g_objpos++]=0x34160000|g_line; //ori         s6,zero,xxxx;
+		}
 	}
 	while(g_source[g_srcpos]!=0x0D && g_source[g_srcpos]!=0x0A){
 		err=statement();

--- a/mips/megalopa/compiler.h
+++ b/mips/megalopa/compiler.h
@@ -213,6 +213,7 @@ extern int g_var_mem[ALLOC_BLOCK_NUM];
 extern unsigned short g_var_pointer[ALLOC_BLOCK_NUM];
 extern unsigned short g_var_size[ALLOC_BLOCK_NUM];
 extern char g_temp_area_used;
+extern char g_nolinenum;
 extern int* g_heap_mem;
 extern int g_max_mem;
 extern char g_disable_break;
@@ -221,6 +222,7 @@ extern char g_use_graphic;
 extern unsigned short* g_graphic_area;
 extern int* g_libparams;
 extern int g_long_name_var_num;
+extern char g_music_active;
 extern int g_class;
 extern int g_compiling_class;
 extern int g_temp;
@@ -260,6 +262,7 @@ void err_not_field(int fieldname, int classname);
 void err_str(char* str);
 char* resolve_label(int s6);
 
+void musicint();
 void set_sound(unsigned long* data, int flagsLR);
 int musicRemaining(int flagsLR);
 int waveRemaining(int mode);
@@ -367,6 +370,13 @@ char* static_statement();
 char* static_method(char type);
 char* resolve_unresolved(int class);
 
+void init_timer();
+void stop_timer();
+char* usetimer_statement();
+char* timer_statement();
+char* timer_function();
+char* interrupt_statement();
+
 /* Error messages */
 #define ERR_SYNTAX (char*)(g_err_str[0])
 #define ERR_NE_BINARY (char*)(g_err_str[1])
@@ -474,6 +484,25 @@ char* resolve_unresolved(int class);
 #define ASM_LW_A0_XXXX_S8 0x8FC40000
 #define ASM_LW_A0_XXXX_S5 0x8EA40000
 
+// Interrupt macros
+// 32 different type interruptions are possible
+// See also envspecific.h for additional interruptions
+#define INTERRUPT_TIMER     0
+#define INTERRUPT_DRAWCOUNT 1
+#define INTERRUPT_KEYS      2
+#define INTERRUPT_INKEY     3
+#define INTERRUPT_MUSIC     4
+#define INTERRUPT_WAVE      5
+
+extern int g_interrupt_flags;
+extern int g_int_vector[];
+#define raise_interrupt_flag(x) do {\
+	if (g_int_vector[x]) {\
+		IFS0bits.CS1IF=1;\
+		g_interrupt_flags|=(1<<(x));\
+	}\
+} while(0)
+
 // Division macro for unsigned long
 // Valid for 31 bits for all cases and 32 bits for some cases
 #define div32(x,y,z) ((((unsigned long long)((unsigned long)(x)))*((unsigned long long)((unsigned long)(y))))>>(z))

--- a/mips/megalopa/debug.c
+++ b/mips/megalopa/debug.c
@@ -228,11 +228,14 @@ static const char initext[]=
 "#PRINT\n";
 
 static const char bastext[]=
-"print getdir$()\n"
-"end\n"
-"\n"
+"I=1:WHILE I<=10\n"
+"I=I+1:WEND\n"
 "\n"
+"I=1:DO\n"
+"I=I+1:LOOP UNTIL I=11\n"
 "\n"
+"FOR I=1 TO 10\n"
+"NEXT\n"
 "\n"
 "\n"
 "\n";
@@ -268,12 +271,10 @@ static const void* debugjumptable[]={
 	FSfopen,
 };
 
+#define for2(x,y,z) for(x=y;x<=z;x++)
+
 int _debug_test(int a0, int a1, int a2, int a3, int param4, int param5){
 	asm volatile(".set noreorder");
-	asm volatile("lw $a0,4($s5)");
-	asm volatile("lw $a1,8($s5)");
-	asm volatile("lw $a2,12($s5)");
-	asm volatile("lw $a3,16($s5)");
 	asm volatile("nop");
 	asm volatile("nop");
 	asm volatile("nop");
@@ -281,6 +282,12 @@ int _debug_test(int a0, int a1, int a2, int a3, int param4, int param5){
 	asm volatile("nop");
 	asm volatile("nop");
 	asm volatile("nop");
+	asm volatile("nop");
+	asm volatile("nop");
+	asm volatile("nop");
+	asm volatile("nop");
+	asm volatile("nop");
+	a2&=0xFFFFFFFC;
 	return a2+a3;
 }
 

--- a/mips/megalopa/envspecific.h
+++ b/mips/megalopa/envspecific.h
@@ -8,6 +8,7 @@
 // Megalopa uses I/O statements/functions
 #include "io.h"
 
+#define CPU_CLOCK_HZ 95454533
 #define PERSISTENT_RAM_SIZE (1024*100)
 
 int readbuttons();
@@ -108,3 +109,5 @@ enum extra{
 	EXTRA_SPISWAPDATA  =EXTRA_STEP*25,
 	// MAX 63
 };
+
+#define ADDITIONAL_INTERRUPT_FUNCTIONS

--- a/mips/megalopa/exception.c
+++ b/mips/megalopa/exception.c
@@ -44,7 +44,12 @@ void dumpMemory(){
 void dumpMemory(){}
 #endif //ifdef DUMPFILE
 
+void _general_exception_handler_main (void);
 void _general_exception_handler (void){
+	asm volatile("la $sp,%0"::"i"(&RAM[RAMSIZE-4]));
+	asm volatile("j _general_exception_handler_main");
+}
+void _general_exception_handler_main (void){
 	int i;
 	// $v1 is g_ex_data
 	asm volatile("la $v1,%0"::"i"(&g_ex_data[0]));
@@ -79,7 +84,9 @@ void _general_exception_handler (void){
 			if((readbuttons()&(KEYUP|KEYDOWN|KEYLEFT|KEYRIGHT|KEYSTART|KEYFIRE))
 				!=(KEYUP|KEYDOWN|KEYLEFT|KEYRIGHT|KEYSTART|KEYFIRE)) i=0;
 		}
-		asm volatile("j SoftReset");
+		RCONbits.POR=0;
+		RCONbits.EXTR=0;
+		asm volatile("j 0x9FC00000");
 	#endif
 }
 

--- a/mips/megalopa/file.c
+++ b/mips/megalopa/file.c
@@ -122,7 +122,10 @@ int compile_and_link_file(char* buff,char* appname){
 			printchar('\n');
 			return -1;
 		}
-	
+
+		// Option initialization(s)
+		g_nolinenum=0;
+
 		// Compile the file
 		err=compile_file();
 		close_file();

--- a/mips/megalopa/function.c
+++ b/mips/megalopa/function.c
@@ -157,7 +157,6 @@ char* rnd_function(){
 	return 0;
 }
 
-
 char* chr_function(void){
 	char* err;
 	err=get_value();
@@ -597,6 +596,7 @@ static const void* int_func_list[]={
 	"PLAYWAVE(",playwave_function,
 	"NEW(",new_function,
 	"SETDIR(",setdir_function,
+	"TIMER(",timer_function,
 	// Additional functions follow
 	ADDITIONAL_INT_FUNCTIONS
 };

--- a/mips/megalopa/globalvars.c
+++ b/mips/megalopa/globalvars.c
@@ -55,6 +55,9 @@ unsigned short g_var_size[ALLOC_BLOCK_NUM];
 // Flag to use temporary area when compiling
 char g_temp_area_used;
 
+// Flag to use option nolinenum
+char g_nolinenum;
+
 // Heap area
 int* g_heap_mem;
 int g_max_mem;
@@ -80,6 +83,9 @@ int* g_libparams;
 // Number of long name variables
 int g_long_name_var_num;
 
+// Flag for active music/sound/wave function
+char g_music_active;
+
 // Class name being compiled
 int g_class;
 // Flag to compile class file

--- a/mips/megalopa/megalopa.mcp
+++ b/mips/megalopa/megalopa.mcp
@@ -71,6 +71,7 @@ file_043=.
 file_044=.
 file_045=.
 file_046=.
+file_047=.
 [GENERATED_FILES]
 file_000=no
 file_001=no
@@ -119,6 +120,7 @@ file_043=no
 file_044=no
 file_045=no
 file_046=no
+file_047=no
 [OTHER_FILES]
 file_000=no
 file_001=no
@@ -163,10 +165,11 @@ file_039=no
 file_040=no
 file_041=no
 file_042=no
-file_043=yes
+file_043=no
 file_044=yes
 file_045=yes
 file_046=yes
+file_047=yes
 [FILE_INFO]
 file_000=compiler.c
 file_001=debug.c
@@ -196,25 +199,26 @@ file_024=spi.c
 file_025=class.c
 file_026=args.c
 file_027=interface\keyinput.c
-file_028=api.h
-file_029=compiler.h
-file_030=debug.h
-file_031=editor.h
-file_032=main.h
-file_033=envspecific.h
-file_034=io.h
-file_035=interface\keyinput.h
-file_036=interface\lib_video_megalopa.h
-file_037=interface\ps2keyboard.h
-file_038=interface\sdfsio370f.h
-file_039=interface\lib_videoout_megalopa.X.a
-file_040=interface\ps2keyboard370f.X.a
-file_041=interface\sdfsio370fLib.X.a
-file_042=app_p32MX370F512H.ld
-file_043=help.txt
-file_044=reservednames.js
-file_045=class.txt
-file_046=sharedfiles.js
+file_028=timer.c
+file_029=api.h
+file_030=compiler.h
+file_031=debug.h
+file_032=editor.h
+file_033=main.h
+file_034=envspecific.h
+file_035=io.h
+file_036=interface\keyinput.h
+file_037=interface\lib_video_megalopa.h
+file_038=interface\ps2keyboard.h
+file_039=interface\sdfsio370f.h
+file_040=interface\lib_videoout_megalopa.X.a
+file_041=interface\ps2keyboard370f.X.a
+file_042=interface\sdfsio370fLib.X.a
+file_043=app_p32MX370F512H.ld
+file_044=help.txt
+file_045=reservednames.js
+file_046=class.txt
+file_047=sharedfiles.js
 [SUITE_INFO]
 suite_guid={62D235D8-2DB2-49CD-AF24-5489A6015337}
 suite_state=

--- a/mips/megalopa/music.c
+++ b/mips/megalopa/music.c
@@ -142,7 +142,6 @@ int waveRemaining(int mode){
 	return ret;
 }
 
-#pragma interrupt musicint IPL2SOFT vector 1
 void musicint(){
 	static unsigned short wavtable_pos;
 	static int music_freq_L=0;
@@ -151,7 +150,6 @@ void musicint(){
 	static int music_timer_R=0;
 	unsigned int i,j;
 	// This function is called every 1/60 sec.
-	IFS0bits.CS0IF=0;
 	switch(g_sound_mode){
 		case SOUND_MODE_WAVE:
 			// Initialize parameters
@@ -169,6 +167,8 @@ void musicint(){
 				g_fhandle=0;
 				g_sound_mode=SOUND_MODE_NONE;
 				stop_music();
+				// Raise WAVE interrupt flag
+				raise_interrupt_flag(INTERRUPT_WAVE);
 				break;
 			}
 			// Continue to MUSIC sound mode
@@ -197,6 +197,10 @@ void musicint(){
 						g_musicstartL++;
 						g_musicstartL&=31;
 						g_musicwaitL=g_musiclenL[g_musicstartL];
+						if (((g_musicstartL+1)&31)==g_musicendL) {
+							// Raise MUSIC interrupt flag
+							raise_interrupt_flag(INTERRUPT_MUSIC);
+						}
 					}
 				}
 			} else if (g_musicstartL!=g_musicendL) {
@@ -206,6 +210,10 @@ void musicint(){
 					g_musicstartL++;
 					g_musicstartL&=31;
 					g_musicwaitL=g_musiclenL[g_musicstartL];
+					if (((g_musicstartL+1)&31)==g_musicendL) {
+						// Raise MUSIC interrupt flag
+						raise_interrupt_flag(INTERRUPT_MUSIC);
+					}
 				}
 			} else {
 				music_freq_L=0;
@@ -234,6 +242,10 @@ void musicint(){
 						g_musicstartR++;
 						g_musicstartR&=31;
 						g_musicwaitR=g_musiclenR[g_musicstartR];
+						if (((g_musicstartR+1)&31)==g_musicendR) {
+							// Raise MUSIC interrupt flag
+							raise_interrupt_flag(INTERRUPT_MUSIC);
+						}
 					}
 				}
 			} else if (g_musicstartR!=g_musicendR) {
@@ -243,6 +255,10 @@ void musicint(){
 					g_musicstartR++;
 					g_musicstartR&=31;
 					g_musicwaitR=g_musiclenR[g_musicstartR];
+					if (((g_musicstartR+1)&31)==g_musicendR) {
+						// Raise MUSIC interrupt flag
+						raise_interrupt_flag(INTERRUPT_MUSIC);
+					}
 				}
 			} else {
 				music_freq_R=0;
@@ -420,11 +436,6 @@ void init_music(){
 
 	// Move OC4RS and OC3 RS from 0x00 to 0x80
 	g_sound_mode=SOUND_MODE_NONE;
-	// Enable interrupt
-	IPC0bits.CS0IP=2;
-	IPC0bits.CS0IS=0;
-	IFS0bits.CS0IF=0;
-	IEC0bits.CS0IE=1;
 }
 
 void musicSetL(){
@@ -629,6 +640,7 @@ void set_sound(unsigned long* data, int flagsLR){
 	if (flagsLR & MFLAG_L) g_soundwaitL=g_soundlenL[0];
 	if (flagsLR & MFLAG_R) g_soundwaitR=g_soundlenR[0];
 	IEC0bits.CS0IE=1; // Restart interrupt.
+	g_music_active=1;// Activate music system
 }
 
 void set_music(char* str, int flagsLR){
@@ -741,6 +753,7 @@ void set_music(char* str, int flagsLR){
 		// Go to next character
 		while(0<g_mstr[g_mspos] && g_mstr[g_mspos]<=0x20 || g_mstr[g_mspos]=='|') g_mspos++;
 	}
+	g_music_active=1;// Activate music system
 }
 
 /*
@@ -886,6 +899,7 @@ void play_wave(char* filename, int start){
 	// Enable intterupt
 	IFS0bits.CS0IF=0;
 	IEC0bits.CS0IE=1;
+	g_music_active=1;// Activate music system
 }
 
 void stop_music(){
@@ -899,4 +913,6 @@ void stop_music(){
 		FSfclose(g_fhandle);
 		g_fhandle=0;
 	}
+	// Inactive music
+	g_music_active=0;
 }

--- a/mips/megalopa/reservednames.js
+++ b/mips/megalopa/reservednames.js
@@ -110,6 +110,7 @@ var namearray=[
 	'NEXT',
 	'NEW',
 	'NOT',
+	'OPTION',
 	'PCG',
 	'PEEK',
 	'PEEK16',
@@ -138,6 +139,7 @@ var namearray=[
 	'SYSTEM',
 	'TAN',
 	'TANH',
+	'TIMER',
 	'TVRAM',
 	'UNTIL',
 	'USEPCG',

--- a/mips/megalopa/run.c
+++ b/mips/megalopa/run.c
@@ -116,6 +116,7 @@ int runbasic(char *appname,int test){
 
 	// Warm up environment
 	pre_run();
+	init_timer();
 
 	// Execute program
 	// Start program from the beginning of RAM.
@@ -126,6 +127,7 @@ int runbasic(char *appname,int test){
 	// Cool down environment
 	post_run();
 	lib_file(FUNC_FINIT,0,0,0);
+	stop_timer();
 
 	return 0;
 }

--- a/mips/megalopa/sharedfiles.js
+++ b/mips/megalopa/sharedfiles.js
@@ -28,6 +28,7 @@ var filearray=[
 	'run.c',
 	'string.c',
 	'statement.c',
+	'timer.c',
 	'value.c',
 	'varname.c',
 	'compiler.h',

--- a/mips/megalopa/statement.c
+++ b/mips/megalopa/statement.c
@@ -1550,6 +1550,24 @@ char* setdir_statement(){
 	return 0;
 }
 
+char* option_statement(){
+	while(1){
+		next_position();
+		if (nextCodeIs("NOLINENUM")) {
+			g_nolinenum=1;
+		} else {
+			return ERR_SYNTAX;
+		}
+		next_position();
+		if (g_source[g_srcpos]==',') {
+			g_srcpos++;
+		} else {
+			break;
+		}
+	}
+	return 0;
+}
+
 #ifdef __DEBUG
 	char* debug_statement(){
 		call_lib_code(LIB_DEBUG);
@@ -1698,6 +1716,10 @@ static const void* statement_list[]={
 	"CALL ",call_statement,
 	"STATIC ",static_statement,
 	"SETDIR ",setdir_statement,
+	"OPTION ",option_statement,
+	"USETIMER ",usetimer_statement,
+	"TIMER ",timer_statement,
+	"INTERRUPT ",interrupt_statement,
 	// List of additional statements follows
 	ADDITIONAL_STATEMENTS
 };

--- /dev/null
+++ b/mips/megalopa/timer.c
@@ -0,0 +1,326 @@
+/*
+   This file is provided under the LGPL license ver 2.1.
+   Written by Katsumi.
+   http://hp.vector.co.jp/authors/VA016157/
+   [e-mail]
+*/
+
+/*
+	This file is shared by Megalopa and Zoea
+*/
+
+#include <xc.h>
+#include "compiler.h"
+#include "api.h"
+
+/*
+	32 different type interruptions are possible.
+	See definition in compiler.h like:
+		#define INTERRUPT_TIMER 0
+		extern int g_interrupt_flags;
+		extern int g_int_vector[];
+		#define raise_interrupt_flag(x) do {\
+*/
+
+// Timer value that increments every timer event
+static int g_timer;
+
+// Interrupt types
+static const void* interrupt_list[]={
+	"TIMER",    (void*)INTERRUPT_TIMER,
+	"DRAWCOUNT",(void*)INTERRUPT_DRAWCOUNT,
+	"KEYS",     (void*)INTERRUPT_KEYS,
+	"INKEY",    (void*)INTERRUPT_INKEY,
+	"MUSIC",    (void*)INTERRUPT_MUSIC,
+	"WAVE",     (void*)INTERRUPT_WAVE,
+	ADDITIONAL_INTERRUPT_FUNCTIONS
+};
+#define NUM_INTERRUPT_TYPES ((sizeof(interrupt_list)/sizeof(interrupt_list[0]))/2)
+// Flags for interrupt
+int g_interrupt_flags;
+// Jump address when interrupt
+int g_int_vector[NUM_INTERRUPT_TYPES];
+
+/*
+	Initialize and termination
+*/
+
+void init_timer(){
+	int i;
+	// Stop timer, first
+	T1CON=0x0000;
+	IEC0bits.T1IE=0;
+	TMR1=0;
+	PR1=0xffff;
+	g_timer=0;
+	// Disable interrupt
+	IEC0bits.CS1IE=0;
+	for(i=0;i<NUM_INTERRUPT_TYPES;i++) g_int_vector[i]=0;
+	// CS0 interrupt every 1/60 sec (triggered by Timer2)
+	IPC0bits.CS0IP=3;
+	IPC0bits.CS0IS=0;
+	IFS0bits.CS0IF=0;
+	IEC0bits.CS0IE=1;	
+}
+
+void stop_timer(){
+	// Stop timer
+	T1CON=0x0000;
+	IEC0bits.T1IE=0;
+	// Disable interrupt
+	IEC0bits.CS1IE=0;
+}
+
+/*
+	Timer interprtation
+*/
+
+// Interrupt handler
+#ifndef __DEBUG
+	// Timer1 is also used for debug mode
+	#pragma interrupt T1Handler IPL2SOFT vector 4
+#endif
+void T1Handler(void){
+	g_timer++;
+	// Clear Timer1 interrupt flag
+	IFS0bits.T1IF=0;
+	// Raise TIMER interrupt flag
+	raise_interrupt_flag(INTERRUPT_TIMER);
+}
+
+void lib_usetimer(int hz){
+	int temppr1;
+	// Stop timer, first
+	T1CON=0x0000;
+	IEC0bits.T1IE=0;
+	TMR1=0;
+	PR1=0xffff;
+	if (!hz) {
+		return;
+	}
+	// PR1 setting
+	temppr1=CPU_CLOCK_HZ/hz;
+	if (temppr1<=65536) {
+		// no prescaler
+		T1CON=0x0000;
+		PR1=temppr1-1;
+	} else if ((temppr1>>3)<=65536) {
+		// 1/8 prescaler
+		T1CON=0x0010;
+		PR1=(temppr1>>3)-1;
+	} else if ((temppr1>>6)<=65536) {
+		// 1/64 prescaler
+		T1CON=0x0020;
+		PR1=(temppr1>>6)-1;
+	} else if ((temppr1>>8)<=65536) {
+		// 1/256 prescaler
+		T1CON=0x0030;
+		PR1=(temppr1>>8)-1;
+	} else {
+		err_invalid_param();
+	}
+	// Timer1 interrupt: priority 2
+	IPC1bits.T1IP=2;
+	IPC1bits.T1IS=0;
+	IEC0bits.T1IE=1;
+	// Start timer
+	T1CONbits.ON=1;
+}
+
+char* usetimer_statement(){
+	char* err;
+	err=get_value();
+	if (err) return err;
+	call_quicklib_code(lib_usetimer,ASM_ADDU_A0_V0_ZERO);
+	return 0;
+}
+
+char* timer_statement(){
+	int i;
+	char* err;
+	err=get_value();
+	if (err) return err;
+	i=(int)(&g_timer);
+	check_obj_space(3);
+	g_object[g_objpos++]=0x3C030000|((i>>16)&0x0000FFFF); // lui v1,xxxx
+	g_object[g_objpos++]=0x34630000|(i&0x0000FFFF);       // ori v1,v1,xxxx
+	g_object[g_objpos++]=0xAC620000;                      // sw  v0,0(v1)
+	return 0;
+}
+
+char* timer_function(){
+	int i;
+	i=(int)(&g_timer);
+	check_obj_space(3);
+	g_object[g_objpos++]=0x3C020000|((i>>16)&0x0000FFFF); // lui v0,xxxx
+	g_object[g_objpos++]=0x34420000|(i&0x0000FFFF);       // ori v0,v0,xxxx
+	g_object[g_objpos++]=0x8C420000;                      // lw  v0,0(v0)
+	return 0;
+}
+
+/*
+	Interrupt interprtation
+	To cause interruption, use raise_interrupt_flag() macro
+	For example,
+		raise_interrupt_flag(INTERRUPT_TIMER);
+
+*/
+
+void BasicInt(int addr){
+	// Note that $s0-$s7 values must be set again here.
+	asm volatile(".set noreorder");
+	// Set s5 for initial_s5_stack
+	asm volatile("la $s5,%0"::"i"(&g_initial_s5_stack[2]));
+	// Set s7 for easy calling call_library()
+	asm volatile("la $s7,%0"::"i"(&call_library));
+	// $a0 is the address in BASIC code
+	asm volatile("jr $a0");
+	asm volatile("nop");
+}
+#pragma interrupt CS1Handler IPL1SOFT vector 2
+void CS1Handler(void){
+	int i;
+	// Store s0-s7, fp, and ra in stacks
+	asm volatile("#":::"s0");
+	asm volatile("#":::"s1");
+	asm volatile("#":::"s2");
+	asm volatile("#":::"s3");
+	asm volatile("#":::"s4");
+	asm volatile("#":::"s5");
+	asm volatile("#":::"s6");
+	asm volatile("#":::"s7");
+	asm volatile("#":::"fp");
+	asm volatile("#":::"ra");
+	while(g_interrupt_flags){
+		for(i=0;i<NUM_INTERRUPT_TYPES;i++){
+			if (g_interrupt_flags & (1<<i)) {
+				if (g_int_vector[i]) BasicInt(g_int_vector[i]);
+				g_interrupt_flags &= (1<<i)^0xffff;
+			}
+		}
+	}
+	IFS0bits.CS1IF=0;
+}
+
+void lib_interrupt_main(int itype, int address){
+	// Set address
+	g_int_vector[itype]=address;
+	// CS1 interrupt: priority 1
+	IPC0bits.CS1IP=1;
+	IPC0bits.CS1IS=0;
+	IEC0bits.CS1IE=1;
+}
+
+void lib_interrupt(int itype){
+	// $ra contains the address for interrupt
+	// $ra is 2 word before the interrupt address
+	asm volatile("addiu $a1,$ra,8");
+	asm volatile("j lib_interrupt_main");
+}
+
+char* interrupt_statement(){
+	int itype;
+	int i,opos;
+	char* err;
+	int stop=0;
+	// Check if STOP
+	stop=nextCodeIs("STOP ");
+	// Seek the interrupt
+	for (i=0;i<NUM_INTERRUPT_TYPES;i++){
+		if (nextCodeIs((char*)interrupt_list[i*2])) break;
+	}
+	if (i<NUM_INTERRUPT_TYPES) {
+		// Interrupt found
+		itype=(int)interrupt_list[i*2+1];
+	} else {
+		// Interrupt not found
+		return ERR_SYNTAX;
+	}
+	// Compile INTERRUPT STOP
+	if (stop) {
+		// g_int_vector[itype]=0;
+		i=(int)(&g_int_vector[itype]);
+		i-=g_gp;
+		check_obj_space(1);
+		g_object[g_objpos++]=0xAF800000|(i&0x0000FFFF); // sw          zero,xxxx(gp)
+		return 0;
+	}
+	// Detect ','
+	next_position();
+	if (g_source[g_srcpos]!=',') return ERR_SYNTAX;
+	g_srcpos++;
+	// Store address to call
+	call_quicklib_code(lib_interrupt,ASM_ORI_A0_ZERO_|itype);
+	check_obj_space(4);
+	// Skip the region used for interrupt-calling
+	opos=g_objpos;
+	g_object[g_objpos++]=0x10000000; // b   xxxxx
+	g_object[g_objpos++]=0x00000000; // nop
+	// Begin interrupt-calling region
+	// Store $ra
+	g_object[g_objpos++]=0x27BDFFFC; // addiu       sp,sp,-4
+	g_object[g_objpos++]=0xAFBF0004; // sw          ra,4(sp)
+	// Compile as GOSUB statement
+	err=gosub_statement();
+	if (err) return err;
+	// Retore $ra and return
+	check_obj_space(3);
+	g_object[g_objpos++]=0x8FBF0004; // lw          ra,4(sp)
+	g_object[g_objpos++]=0x03E00008; // jr          ra
+	g_object[g_objpos++]=0x08320004; // addiu       sp,sp,4
+	// End interrupt-calling region
+	// Complete B assembly
+	g_object[opos]|=g_objpos-opos-1;
+	return 0;
+}
+
+/*
+	CS0 interrupt
+	IPL3SOFT vector 1
+
+	This interrupt is always active. Therefore, Do things as few as possible.
+	1) Call music function if needed.
+		MUSIC interrupt is taken by music.c
+	2) Check buttons for KEYS interrupt
+	3) Check PS/2 for INKEY interrupt
+	4) DRAWCOUNT interrupt
+*/
+
+const int* keystatus=(int*)&ps2keystatus[0];
+
+#pragma interrupt CS0Handler IPL3SOFT vector 1
+void CS0Handler(void){
+	static int s_keys=-1;
+	static char s_inkey=0;
+	int i;
+	IFS0bits.CS0IF=0;
+	// Call music function
+	if (g_music_active) musicint();
+	// The interrupts are valid only when CS1 is active
+	if (IEC0bits.CS1IE) {
+		// Raise DRAWCOUNT interrupt flag
+		raise_interrupt_flag(INTERRUPT_DRAWCOUNT);
+		// Check buttons
+		if (0<=s_keys && s_keys!=(KEYPORT&(KEYUP|KEYDOWN|KEYLEFT|KEYRIGHT|KEYSTART|KEYFIRE))) {
+			// Raise KEYS interrupt flag
+			raise_interrupt_flag(INTERRUPT_KEYS);
+		}
+		s_keys=KEYPORT&(KEYUP|KEYDOWN|KEYLEFT|KEYRIGHT|KEYSTART|KEYFIRE);
+		// Check PS/2 keyboard down
+		if (g_int_vector[INTERRUPT_INKEY]) {
+			for(i=0;i<64;i++){
+				if (keystatus[i]) {
+					// Raise INKEY interrupt flag
+					if (!s_inkey) raise_interrupt_flag(INTERRUPT_INKEY);
+					break;
+				}
+			}
+			s_inkey=(i==64) ? 0:1;
+		}
+	}
+}
+/*
+		for(i=0;i<256;i++){
+			if (ps2keystatus[i]) return i;
+		}
+*/

--- a/mips/megalopa/varname.c
+++ b/mips/megalopa/varname.c
@@ -91,6 +91,7 @@ static const int reserved_var_names[]={
 	0x000b4321, /*NEXT*/
 	0x000148f8, /*NEW*/
 	0x00014a5d, /*NOT*/
+	0x38a658d7, /*OPTION*/
 	0x000152c0, /*PCG*/
 	0x000cacec, /*PEEK*/
 	0x3b1c6aea, /*PEEK16*/
@@ -119,6 +120,7 @@ static const int reserved_var_names[]={
 	0x47f711de, /*SYSTEM*/
 	0x000166bf, /*TAN*/
 	0x000f72ed, /*TANH*/
+	0x020ed5f3, /*TIMER*/
 	0x02182fee, /*TVRAM*/
 	0x022c2a2d, /*UNTIL*/
 	0x4e8887d0, /*USEPCG*/

--- a/mips/zoea/sharedfiles.js
+++ b/mips/zoea/sharedfiles.js
@@ -28,6 +28,7 @@ var filearray=[
 	'run.c',
 	'string.c',
 	'statement.c',
+	'timer.c',
 	'value.c',
 	'varname.c',
 	'compiler.h',