Progress on 16b

README.md

@@ -69,6 +69,8 @@ BRK ( RESET )
 - Implement shorthand operators
 - Catch overflow/underflow
 - Jumps should be relative
+- Load program in RAM
+- Signed operations
 
 ### CPU
 

uxn.c

@@ -13,7 +13,7 @@ WITH REGARD TO THIS SOFTWARE.
 
 #define FLAG_HALT 0x01
 #define FLAG_SHORT 0x02
-#define FLAG_CARRY 0x04
+#define FLAG_SIGN 0x04
 #define FLAG_TRAPS 0x08
 
 typedef unsigned char Uint8;
@@ -99,33 +99,36 @@ void wspush8(Uint8 b) { cpu.wst.dat[cpu.wst.ptr++] = b; }
 void wspush16(Uint16 s) { wspush8(s >> 8); wspush8(s & 0xff); }
 Uint8 wspop8(void) { return cpu.wst.dat[--cpu.wst.ptr]; }
 Uint16 wspop16(void) { return wspop8() + (wspop8() << 8); }
-Uint8 wspeek8(void) { return cpu.wst.dat[cpu.wst.ptr - 1]; }
+Uint8 wspeek8(Uint8 o) { return cpu.wst.dat[cpu.wst.ptr - o]; }
+Uint16 wspeek16(Uint8 o) { return bytes2short(cpu.wst.dat[cpu.wst.ptr - o], cpu.wst.dat[cpu.wst.ptr - o + 1]); }
 Uint16 rspop16(void) { return cpu.rst.dat[--cpu.rst.ptr]; }
 void rspush16(Uint16 a) { cpu.rst.dat[cpu.rst.ptr++] = a; }
 
 /* new flexy pop/push */
 
-
 void op_brk() { setflag(FLAG_HALT, 1); }
 void op_rts() {	cpu.rom.ptr = rspop16(); }
 void op_lit() { cpu.literal += cpu.rom.dat[cpu.rom.ptr++]; }
+
 void op_drp() { wspop8(); }
-void op_dup() { wspush8(wspeek8()); }
+void op_dup() { wspush8(wspeek8(1)); }
 void op_swp() { Uint8 b = wspop8(), a = wspop8(); wspush8(b); wspush8(a); }
-void op_ovr() { wspush8(cpu.wst.dat[cpu.wst.ptr - 2]); }
+void op_ovr() { Uint8 a = wspeek8(2); wspush8(a); }
 void op_rot() { Uint8 c = wspop8(),b = wspop8(),a = wspop8(); wspush8(b); wspush8(c); wspush8(a); }
-void op_jmu() { cpu.rom.ptr = wspop8(); }
+
+void op_jmu() { cpu.rom.ptr = wspop16(); }
 void op_jsu() { rspush16(cpu.rom.ptr); cpu.rom.ptr = wspop16(); }
-void op_jmc() { if(wspop8()) op_jmu(); }
-void op_jsc() { if(wspop8()) op_jsu(); }
-void op_equ() { wspush8(wspop8() == wspop8()); }
-void op_neq() { wspush8(wspop8() != wspop8()); }
-void op_gth() { wspush8(wspop8() < wspop8()); }
-void op_lth() { wspush8(wspop8() > wspop8()); }
-void op_and() { wspush8(wspop8() & wspop8()); }
-void op_ora() { wspush8(wspop8() | wspop8()); }
-void op_rol() { wspush8(wspop8() << 1); }
-void op_ror() { wspush8(wspop8() >> 1); }
+void op_jmc() { Uint8 a = wspop8(); if(a) op_jmu(); }
+void op_jsc() { Uint8 a = wspop8(); if(a) op_jsu(); }
+
+void op_equ() { Uint8 a = wspop8(), b = wspop8(); wspush8(a == b); }
+void op_neq() { Uint8 a = wspop8(), b = wspop8(); wspush8(a != b); }
+void op_gth() { Uint8 a = wspop8(), b = wspop8(); wspush8(a < b); }
+void op_lth() { Uint8 a = wspop8(), b = wspop8(); wspush8(a > b); }
+void op_and() { Uint8 a = wspop8(), b = wspop8(); wspush8(a & b); }
+void op_ora() { Uint8 a = wspop8(), b = wspop8(); wspush8(a | b); }
+void op_rol() { Uint8 a = wspop8(), b = wspop8(); wspush8(a << b); }
+void op_ror() { Uint8 a = wspop8(), b = wspop8(); wspush8(a >> b); }
 void op_add() { Uint8 a = wspop8(), b = wspop8(); wspush8(a + b); }
 void op_sub() { Uint8 a = wspop8(), b = wspop8(); wspush8(a - b); }
 void op_mul() { Uint8 a = wspop8(), b = wspop8(); wspush8(a * b); }
@@ -135,6 +138,20 @@ void op_str() { cpu.ram.dat[wspop16()] = wspop8(); }
 void op_pek() { wspush8(cpu.rom.dat[wspop16()]); }
 void op_pok() { printf("TODO:\n");}
 
+void op_drp16() { wspop16(); }
+void op_dup16() { wspush16(wspeek16(2)); }
+void op_swp16() { Uint16 b = wspop16(), a = wspop16(); wspush16(b); wspush16(a); }
+void op_ovr16() { Uint16 a = wspeek16(4); wspush16(a); }
+void op_rot16() { Uint16 c = wspop16(), b = wspop16(), a = wspop16(); wspush16(b); wspush16(c); wspush16(a); }
+
+void op_equ16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a == b); }
+void op_neq16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a != b); }
+void op_gth16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a < b); }
+void op_lth16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a > b); }
+void op_and16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a & b); }
+void op_ora16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a | b); }
+void op_rol16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a << b); }
+void op_ror16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a >> b); }
 void op_add16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a + b); }
 void op_sub16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a - b); }
 void op_mul16() { Uint16 a = wspop16(), b = wspop16(); wspush16(a * b); }
@@ -148,9 +165,9 @@ void (*ops8[])() = {
 };
 
 void (*ops16[])() = {
-	op_brk, op_rts, op_lit, op_drp, op_dup, op_swp, op_ovr, op_rot, 
+	op_brk, op_rts, op_lit, op_drp16, op_dup16, op_swp16, op_ovr16, op_rot16, 
 	op_jmu, op_jsu, op_jmc, op_jsc, op_equ, op_neq, op_gth, op_lth, 
-	op_and, op_ora, op_rol, op_ror, op_add16, op_sub16, op_mul16, op_div16,
+	op_and16, op_ora16, op_rol16, op_ror16, op_add16, op_sub16, op_mul16, op_div16,
 	op_ldr, op_str, op_pek, op_pok, op_brk, op_brk, op_brk, op_brk
 };
 
@@ -211,8 +228,7 @@ eval(void)
 	/* when opcode */
 	opc(instr, &op);
 	setflag(FLAG_SHORT, (instr >> 5) & 1);
-	if((instr >> 6) & 1)
-		printf("Unused flag: %02x\n", instr);
+	setflag(FLAG_SIGN, (instr >> 6) & 1);
 	if((instr >> 7) & 1)
 		printf("Unused flag: %02x\n", instr);
 	/* TODO: setflag(FLAG_B, (instr >> 6) & 1); */
@@ -256,7 +272,7 @@ start(FILE *f)
 	printf("hf: %x zf: %x cf: %x tf: %x\n",
 		getflag(FLAG_HALT) != 0,
 		getflag(FLAG_SHORT) != 0,
-		getflag(FLAG_CARRY) != 0,
+		getflag(FLAG_SIGN) != 0,
 		getflag(FLAG_TRAPS) != 0);
 	printf("\n");
 	return 1;

uxnasm.c

@@ -174,8 +174,8 @@ findop(char *s)
 		while(s[3 + m]) {
 			char c = s[3 + m];
 			if(c == '^') i |= (1 << 5); /* mode: 16 bits */
-			if(c == '&') i |= (1 << 6); /* mode: unused */
-			if(c == '~') i |= (1 << 7); /* mode: unused */
+			if(c == '~') i |= (1 << 6); /* mode: signed */
+			if(c == '&') i |= (1 << 7); /* mode: unused */
 			m++;
 		}
 		return i;