@@ -34,6 +34,8 @@ evaluxn(u, u->vframe); /* Each frame

 - `,literal`, push label value to stack, prefixed with `LIT LEN`.

 - `.pointer`, push label value to stack.

+- `+1234`, push positive lit signed value to stack.

+- `-abcd`, push negative lit signed value to stack.

 ### Special

@@ -82,14 +84,12 @@ BRK

 ## TODOs

-- Implement signed flag to operators.

+- Line routine

 - On-screen debugger.

 - Auto-advance ldr?

 - Getting rid of IOR/IOW would be nice..

 - Sending from the wst to the rst, balance mode/flag?

 - Device that works like an extra memory bank

-- Line routine

-- LineRect routine

 - Draw a chr sprite.

 ## Refs

@@ -12,7 +12,9 @@ WITH REGARD TO THIS SOFTWARE.

 */

 typedef unsigned char Uint8;

+typedef signed char Sint8;

 typedef unsigned short Uint16;

+typedef signed short Sint16;

 typedef struct {

 	int ptr;

@@ -61,6 +63,7 @@ pushbyte(Uint8 b, int lit)

 void

 pushshort(Uint16 s, int lit)

 {

+	printf("%04x[%d]\n", s, lit);

 	if(lit) {

 		pushbyte(0x03, 0);

 		pushbyte(0x02, 0);

@@ -100,7 +103,7 @@ findoperator(char *s)

 			continue;

 		while(s[3 + m]) {

 			if(s[3 + m] == '^') i |= (1 << 5); /* mode: 16 bits */

-			if(s[3 + m] == '~') i |= (1 << 6); /* mode: signed */

+			if(s[3 + m] == '!') i |= (1 << 6); /* mode: signed */

 			if(s[3 + m] == '?') i |= (1 << 7); /* mode: conditional */

 			m++;

 		}

@@ -124,6 +127,8 @@ makelabel(char *name, Uint16 addr)

 	Label *l;

 	if(findlabel(name))

 		return error("Label duplicate", name);

+	if(sihx(name))

+		return error("Label name is hex number", name);

 	l = &labels[labelslen++];

 	l->addr = addr;

 	scpy(name, l->name, 64);

@@ -176,6 +181,8 @@ pass1(FILE *f)

 			case '"': addr += slen(w + 1) + 2; break;

 			case '#': addr += 4; break;

 			case '.': addr += 2; break;

+			case '+': /* signed positive */

+			case '-': /* signed negative */

 			case ',':

 				addr += (sihx(w + 1) && slen(w + 1) == 2 ? 1 : 2);

 				addr += (sihx(w + 1) ? slen(w + 1) / 2 : 2);

@@ -198,26 +205,22 @@ pass2(FILE *f)

 		Label *l;

 		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] == '#')

-			pushshort(shex(w + 1) & 0xff, 1);

-		else if((l = findlabel(w + 1)))

-			pushshort(l->addr, w[0] == ',');

-		else if((op = findoperator(w)) || scmp(w, "BRK"))

-			pushbyte(op, 0);

-		else if(sihx(w + 1) && slen(w + 1) == 2)

-			pushbyte(shex(w + 1), w[0] == ',');

-		else if(sihx(w + 1) && slen(w + 1) == 4)

-			pushshort(shex(w + 1), w[0] == ',');

-		else

-			return error("Unknown label", w);

+		/* clang-format off */

+		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] == '+' && sihx(w + 1) && slen(w + 1) == 2) pushbyte((Sint8)shex(w + 1), 1);

+		else if(w[0] == '+' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)shex(w + 1), 1);

+		else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 2) pushbyte((Sint8)(shex(w + 1) * -1), 1);

+		else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)(shex(w + 1) * -1), 1);

+		else if(w[0] == '"') pushtext(w + 1);

+		else if(w[0] == '#') pushshort(shex(w + 1) & 0xff, 1);

+		else if((l = findlabel(w + 1))) pushshort(l->addr, w[0] == ',');

+		else if((op = findoperator(w)) || scmp(w, "BRK")) pushbyte(op, 0);

+		else if(sihx(w + 1) && slen(w + 1) == 2) pushbyte(shex(w + 1), w[0] == ',');

+		else if(sihx(w + 1) && slen(w + 1) == 4) pushshort(shex(w + 1), w[0] == ',');

+		else return error("Unknown label", w);

+		/* clang-format on */

 	}

 	return 1;

 }

@@ -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/line.usm bin/boot.rom

 ./bin/emulator bin/boot.rom

@@ -21,6 +21,12 @@ contexts:

     - match: '\|(\S+)\s?'

       scope: punctuation.definition

       pop: true

+    - match: '\+(\S+)\s?'

+      scope: keyword.control

+      pop: true

+    - match: '\-(\S+)\s?'

+      scope: keyword.control

+      pop: true

   strings:

     - match: '\:(\S+)\s?'

@@ -35,6 +41,9 @@ contexts:

     - match: '\,(\S+)\s?'

       scope: keyword.control

       pop: true

+    - match: '\#(\S+)\s?'

+      scope: keyword.control

+      pop: true

     - match: '\.(\S+)\s?'

       scope: keyword.control

       pop: true

@@ -22,6 +22,18 @@

 ,1234 ,1233 GTH^ #0e STR

 ,1234 ,1235 LTH^ #0f STR

+BRK

+

+@diff8 ( result of abs sub )

+	OVR OVR GTH ,diff8sub ROT JMP? POP^

+	SWP @diff8sub SUB

+RTS

+

+@diff16 ( result of abs sub16 )

+	OVR^ OVR^ GTH^ ,diff16sub ROT JMP? POP^

+	SWP^ @diff16sub SUB^

+RTS

+

 |c000 @FRAME BRK 

 |d000 @ERROR BRK 

 |FFFA .RESET .FRAME .ERROR

@@ -5,6 +5,8 @@

 ;x_ 2 ;y_ 2 ;x0 2 ;y0 2 ;x1 2 ;y1 2 ;color 1

+;dx 2 ;dy 2 ;err 2 ;err2 2

+

 |0100 @RESET

 	( set dev/write to screen ) 

@@ -13,9 +15,10 @@

 	( init positions )

 	,0020 ,x0 STR^ ,0018 ,y0 STR^

-	,0030 ,x1 STR^ ,0048 ,y1 STR^

+	,0060 ,x1 STR^ ,0048 ,y1 STR^

 	,x0 LDR^ ,x_ STR^ ,y0 LDR^ ,y_ STR^

+

 	( draw control points )

 	,02 ,color STR

 	,x0 LDR^ ,y0 LDR^ ,putpixel JSR

@@ -39,6 +42,11 @@ BRK

 	,00 IOW  ( redraw byte )

 	RTS

+@diff16

+	OVR^ OVR^ GTH^ ,diff16sub ROT JMP? POP^

+	SWP^ @diff16sub SUB^

+RTS

+

 |c000 @FRAME BRK 

 |d000 @ERROR BRK 

 |FFFA .RESET .FRAME .ERROR

@@ -3,13 +3,17 @@

 :dev/r fff8 ( std read port )

 :dev/w fff9 ( std write port )

+;x 2

+

 |0100 @RESET 

-	,00 ,dev/w STR ( set dev/write to console ) 

+	,00 ,dev/w STR ( set dev/write to console )

+	-12 +02 LTH!

 BRK

+

 |c000 @FRAME BRK

 |d000 @ERROR BRK 

 |FFFA .RESET .FRAME .ERROR

@@ -33,7 +33,7 @@ Uint16 peek16(St8 *s, Uint8 a) { return peek8(s, a * 2) + (peek8(s, a * 2 + 1) <

 void op_brk(Uxn *u) { setflag(&u->status,FLAG_HALT, 1); }

 void op_li1(Uxn *u) { u->literal += 1; }

 void op_lix(Uxn *u) { u->literal += u->ram.dat[u->ram.ptr++]; }

-void op_nop(Uxn *u) { printf("%02x\n", pop8(&u->wst)); }

+void op_nop(Uxn *u) { printf("0x%02x ", pop8(&u->wst)); }

 void op_ior(Uxn *u) { Device *dev = &u->dev[mempeek8(&u->ram, u->devr)]; if(dev) push8(&u->wst, dev->read(dev, pop8(&u->wst))); }

 void op_iow(Uxn *u) { Uint8 a = pop8(&u->wst); Device *dev = &u->dev[mempeek8(&u->ram, u->devw)]; if(dev) dev->write(dev, a); }

 void op_ldr(Uxn *u) { Uint16 a = pop16(&u->wst); push8(&u->wst, mempeek8(&u->ram, a)); }

@@ -52,14 +52,14 @@ void op_and(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst,

 void op_ora(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b | a); }

 void op_rol(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b << a); }

 /* Arithmetic */

-void op_add(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b + a); }

-void op_sub(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b - a); }

-void op_mul(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b * a); }

-void op_div(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b / a); }

-void op_equ(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b == a); }

-void op_neq(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b != a); }

-void op_gth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b > a); }

-void op_lth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, b < a); }

+void op_add(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b + (Sint8)a : b + a); }

+void op_sub(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b - (Sint8)a : b - a); }

+void op_mul(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b * (Sint8)a : b * a); }

+void op_div(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b / (Sint8)a : b / a); }

+void op_equ(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b == (Sint8)a : b == a); }

+void op_neq(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b != (Sint8)a : b != a); }

+void op_gth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b > (Sint8)a : b > a); }

+void op_lth(Uxn *u) { Uint8 a = pop8(&u->wst), b = pop8(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b < (Sint8)a : b < a); }

 /* --- */

 void op_nop16(Uxn *u) { printf("%04x\n", pop16(&u->wst)); }

 void op_ior16(Uxn *u) { Uint8 a = pop8(&u->wst); Device *dev = &u->dev[mempeek8(&u->ram, u->devr)]; if(dev) push16(&u->wst, (dev->read(dev, a) << 8) + dev->read(dev, a + 1)); }

@@ -76,14 +76,14 @@ void op_and16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u

 void op_ora16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b | a); }

 void op_rol16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b << a); }

 /* Arithmetic(16-bits) */

-void op_add16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b + a); }

-void op_sub16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b - a); }

-void op_mul16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b * a); }

-void op_div16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, b / a); }

-void op_equ16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, b == a); }

-void op_neq16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, b != a); }

-void op_gth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, b > a); }

-void op_lth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, b < a); }

+void op_add16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b + (Sint8)a : b + a); }

+void op_sub16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b - (Sint8)a : b - a); }

+void op_mul16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b * (Sint8)a : b * a); }

+void op_div16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push16(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b / (Sint8)a : b / a); }

+void op_equ16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b == (Sint8)a : b == a); }

+void op_neq16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b != (Sint8)a : b != a); }

+void op_gth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b > (Sint8)a : b > a); }

+void op_lth16(Uxn *u) { Uint16 a = pop16(&u->wst), b = pop16(&u->wst); push8(&u->wst, getflag(&u->status, FLAG_SIGN) ? (Sint8)b < (Sint8)a : b < a); }

 void (*ops[])(Uxn *u) = {

 	op_brk, op_nop, op_li1, op_lix, op_ior, op_iow, op_ldr, op_str, 

@@ -133,7 +133,7 @@ opcuxn(Uxn *u, Uint8 instr)

 {

 	Uint8 op = instr & 0x1f;

 	setflag(&u->status, FLAG_SHORT, (instr >> 5) & 1);

-	setflag(&u->status, FLAG_SIGN, (instr >> 6) & 1); /* usused */

+	setflag(&u->status, FLAG_SIGN, (instr >> 6) & 1);

 	setflag(&u->status, FLAG_COND, (instr >> 7) & 1);

 	if(getflag(&u->status, FLAG_SHORT))

 		op += 32;

@@ -12,7 +12,9 @@ WITH REGARD TO THIS SOFTWARE.

 */

 typedef unsigned char Uint8;

+typedef signed char Sint8;

 typedef unsigned short Uint16;

+typedef signed short Sint16;

 #define FLAG_HALT 0x01

 #define FLAG_SHORT 0x02