*

README.md

@@ -62,9 +62,9 @@ BRK
 
 ## TODOs
 
+- short variable
 - Implement signed flag to operators.
 - On-screen debugger.
-- 16b mode for str/ldr
 - Auto-advance ldr?
 - Getting rid of IOR/IOW would be nice..
 

assembler.c

@@ -139,32 +139,40 @@ makeconst(char *id, FILE *f)
 	return makelabel(id, shex(wv));
 }
 
+int
+makevariable(char *id, Uint16 *addr, FILE *f)
+{
+	char wv[64];
+	Uint8 origin;
+	fscanf(f, "%s", wv);
+	origin = *addr;
+	*addr += shex(wv);
+	return makelabel(id, origin);
+}
+
 int
 pass1(FILE *f)
 {
-	int skip = 0, vars = 0;
+	int skip = 0;
 	Uint16 addr = 0;
 	char w[64];
 	while(fscanf(f, "%s", w) == 1) {
 		if(cmnt(w, &skip))
 			continue;
-		if(w[0] == '@' && !makelabel(w + 1, addr))
+		if(w[0] == '@') {
+			if(!makelabel(w + 1, addr))
 				return error("Pass1 failed", w);
-		if(w[0] == ';' && !makelabel(w + 1, vars++))
+		} else if(w[0] == ';') {
+			if(!makevariable(w + 1, &addr, f))
 				return error("Pass1 failed", w);
-		if(w[0] == ':') {
+		} else if(w[0] == ':') {
 			if(!makeconst(w + 1, f))
 				return error("Pass1 failed", w);
-			else
+		} else if(findoperator(w) || scmp(w, "BRK"))
-				continue;
-		}
-		if(findoperator(w) || scmp(w, "BRK"))
 			addr += 1;
 		else {
 			switch(w[0]) {
 			case '|': addr = shex(w + 1); break;
-			case '@':
-			case ';': break;
 			case '"': addr += slen(w + 1) + 2; break;
 			case '#': addr += 4; break;
 			case '.': addr += 2; break;
@@ -189,12 +197,13 @@ pass2(FILE *f)
 		Uint8 op = 0;
 		Label *l;
 		if(w[0] == '@') continue;
-		if(w[0] == ';') continue;
 		if(cmnt(w, &skip)) continue;
 		if(w[0] == '|')
 			p.ptr = shex(w + 1);
 		else if(w[0] == ':')
 			fscanf(f, "%s", w);
+		else if(w[0] == ';')
+			fscanf(f, "%s", w);
 		else if(w[0] == '"')
 			pushtext(w + 1);
 		else if(w[0] == '#')

build.sh

@@ -24,5 +24,5 @@ rm -f ./bin/emulator
 cc -std=c89 -DDEBUG -Wall -Wno-unknown-pragmas -Wpedantic -Wshadow -Wextra -Werror=implicit-int -Werror=incompatible-pointer-types -Werror=int-conversion -Wvla -g -Og -fsanitize=address -fsanitize=undefined uxn.c emulator.c -L/usr/local/lib -lSDL2 -o bin/emulator
 
 # run
-./bin/assembler examples/test.usm bin/boot.rom
+./bin/assembler examples/pixels.usm bin/boot.rom
 ./bin/emulator bin/boot.rom

emulator.c

@@ -37,7 +37,7 @@ SDL_Renderer *gRenderer;
 SDL_Texture *gTexture;
 Uint32 *pixels;
 
-Device *devscreen, *devmouse, *devkey;
+Device *devconsole, *devscreen, *devmouse, *devkey;
 
 int
 error(char *msg, const char *err)
@@ -288,7 +288,7 @@ main(int argc, char **argv)
 	if(!init())
 		return error("Init", "Failed");
 
-	portuxn(&u, "console", consoler, consolew);
+	devconsole = portuxn(&u, "console", consoler, consolew);
 	devscreen = portuxn(&u, "screen", screenr, screenw);
 	devmouse = portuxn(&u, "mouse", mouser, mousew);
 	devkey = portuxn(&u, "key", keyr, keyw);

examples/benchmark.usm

@@ -1,9 +1,5 @@
 ( benchmark )
 
-;iterator
-:dev1r FFF0
-:dev1w FFF1
-
 |0100 @RESET
 
 ( arithmetic ) 

examples/blank.usm

@@ -1,9 +1,5 @@
 ( blank )
 
-;iterator
-:dev1r FFF0
-:dev1w FFF1
-
 |0100 @RESET BRK
 |c000 @FRAME BRK 
 |d000 @ERROR BRK 

examples/pixel.usm

@@ -1,21 +1,27 @@
 ( draw pixel )
 
+:dev/w fff9 ( keep write port in a const )
+;x 2
+;y 2
+
 |0100 @RESET
 	
-	( redraw - color - x - y )
+	( set dev/write to screen ) 
-	,00 ,01 ,0000 ,0000 ,putpixel JSR
+
-	,00 ,02 ,0001 ,0001 ,putpixel JSR
+	,01 ,dev/w STR 
-	,01 ,03 ,0002 ,0002 ,putpixel JSR
+
+	,0020 ,x STR^ ( set x-pos )
+	,0030 ,y STR^ ( set y-pos )
+
+	( IOW will now send to screen ) 
+
+	,y LDR^ IOW^ ( y-pos )
+	,x LDR^ IOW^ ( x-pos )
+	,02 IOW ( color )
+	,01 IOW ( redraw )
 
 BRK
 
-@putpixel 
-	SWP ,01 IOW ,01 IOW ( y )
-	SWP ,01 IOW ,01 IOW ( x )
-	,01 IOW ( color )
-	,01 IOW ( redraw )
-	RTS
-
 |c000 @FRAME BRK 
 |d000 @ERROR BRK 
 |FFFA .RESET .FRAME .ERROR

examples/pixels.usm

@@ -0,0 +1,47 @@
+( my default test file )
+
+:dev/r fff8 ( std read port )
+:dev/w fff9 ( std write port )
+
+;x 2 ;y 2 ;color 1 
+
+|0100 @RESET 
+	
+	,01 ,dev/w STR ( set dev/write to screen ) 
+	,01 ,color STR ( set color ) 	
+	,0020 ,x STR^ ( set x-pos )
+	,0030 ,y STR^ ( set y-pos )
+
+BRK
+
+|c000 @FRAME 
+
+	,colorize JSR
+	,move JSR
+	( draw )
+	,01 ,color LDR ,x LDR^ ,y LDR^ ,putpixel JSR
+
+BRK
+
+@colorize
+	,color LDR ,01 ADD ,color STR ( incr color )
+	,color LDR ,04 LTH RTS?
+	,01 ,color STR 
+	RTS
+
+@move
+	,x LDR^ ,0001 ADD^ ,x STR^ ( incr x )
+	,x LDR^ ,0060 LTH^ RTS?    ( if x > 60 )
+	,0020 ,x STR^              ( x = 0x0020 )
+	,y LDR^ ,0001 ADD^ ,y STR^ ( incr y )
+	RTS
+
+@putpixel 
+	IOW^ ( y short )
+	IOW^ ( x short )
+	IOW ( color byte )
+	IOW ( redraw byte )
+	RTS
+
+|d000 @ERROR BRK 
+|FFFA .RESET .FRAME .ERROR

examples/screen.usm

@@ -2,10 +2,8 @@
 
 :dev/r fff8 ( std read port )
 :dev/w fff9 ( std write port )
-;width0
+;width 2
-;width1
+;height 2
-;height0
-;height1
 
 |0100 @RESET 
 	
@@ -13,14 +11,14 @@
 	,01 DUP ,dev/r STR ,dev/w STR 
 
 	( load screen size )
-	,00 IOR^ ,width0 STR^
+	,00 IOR^ ,width STR^
-	,02 IOR^ ,height0 STR^
+	,02 IOR^ ,height STR^
 
 	( draw pixel at screen center )
 
 	,0101 
-	,width0 LDR^ ,0002 DIV^ 
+	,width LDR^ ,0002 DIV^ 
-	,height0 LDR^ ,0002 DIV^ 
+	,height LDR^ ,0002 DIV^ 
 	,putpixel JSR
 
 BRK

examples/test.usm

@@ -3,34 +3,12 @@
 :dev/r fff8 ( std read port )
 :dev/w fff9 ( std write port )
 
-;i ;x0 ;x1 ;y0 ;y1
-
 |0100 @RESET 
 	
 	,01 ,dev/w STR ( set dev/write screen#01 ) 
 
 BRK
 
-|c000 @FRAME 
+|c000 @FRAME BRK
-	
-	,i LDR ,04 ADD ,i STR ( incr i )
-	,i LDR ,x1 STR ( set x )
-	,changerow JSR ( update y )
-	,01 ,02 ,x0 LDR^ ,y0 LDR^ ,putpixel JSR
-
-BRK
-
-@changerow
-	,i LDR ,00 NEQ RTS?
-	,y1 LDR ,04 ADD ,y1 STR
-	RTS
-
-@putpixel 
-	IOW^ ( y short )
-	IOW^ ( x short )
-	IOW ( color byte )
-	IOW ( redraw byte )
-	RTS
-
 |d000 @ERROR BRK 
 |FFFA .RESET .FRAME .ERROR

uxn.c

@@ -208,6 +208,6 @@ portuxn(Uxn *u, char *name, Uint8 (*rfn)(Device *, Uint8), Uint8 (*wfn)(Device *
 	d->read = rfn;
 	d->write = wfn;
 	d->len = 0;
-	printf("Device#%d: %s \n", u->devices, name);
+	printf("Device #%d: %s \n", u->devices - 1, name);
 	return d;
 }