M xyw.c → xyw.c

@@ -6,8 +6,8 @@ int xyw_debug = 0;
 
 // Instruction mnemonics definition
 const char xyw_instructions[][4] = {
-    "BRK", "PSH", "POP", "LDR",
-    "LDA", "STA", "LDD", "STD",
+    "BRK", "PSH", "POP", "???",
+    "LDB", "LDW", "STB", "STW",
     "INC", "DEC", "SHL", "SHR",
     "ADD", "SUB", "MUL", "DIV",
     "EQU", "NEQ", "GTH", "LTH",

M xywrun.c → xywrun.c

@@ -295,10 +295,14 @@ // Push a value to stack
 #define PUSH(n) do { if (w) { us_pushw(n); } else { us_push(n); } } while(0)
 // Pop value from stack
 #define POP() (w ? us_popw() : (xyw_word)us_pop())
-// Read value from address
-#define READ(addr) (w ? readw(addr) : (xyw_byte)xyw_memory[addr])
-// Write value as word or byte depending on width flag 'w'
-#define WRITE(addr, val) w ? writew(addr, val) : write(addr, (xyw_byte)(val))
+// Read a byte from absolute address or direct page
+#define READB(addr) (w ? read(addr) : read(DIRECT_PAGE | addr))
+// Read a word from absolute address or direct page
+#define READW(addr) (w ? readw(addr) : readw(DIRECT_PAGE | addr))
+// Write a byte to absolute address or direct page
+#define WRITEB(addr, val) w ? write(addr, val) : write(DIRECT_PAGE | addr, val)
+// Write a word to absolute address or direct page
+#define WRITEW(addr, val) w ? writew(addr, val) : writew(DIRECT_PAGE | addr, val)
 
 //// Initialize devices
 
@@ -328,16 +332,6 @@ fclose(fp);
         return -1;
     }
     xyw_dbg("Loaded %zu bytes into memory\n", bytes_read);
-    // Print loaded bytes, including header, 16 per line
-    xyw_dbg("Memory dump:\n");
-    for (size_t i = 0; i < bytes_read; i++)
-    {
-        xyw_dbg("%02X ", xyw_memory[USER_MEMORY_START + i]);
-        if ((i + 1) % 16 == 0)
-        {
-            xyw_dbg("\n");
-        }
-    }
     fclose(fp);
     xyw_memory[SYSTEM_STATE] = 1;
     while (xyw_memory[SYSTEM_STATE] && *pc < SYSTEM_MEMORY_START)
@@ -346,14 +340,14 @@ xyw_dbg("PC: %04X -> %02X (%s) [X:%02X|Y:%02X|XW:%04X|YW:%04X]\n", *pc, xyw_memory[*pc], xyw_instructions[xyw_memory[*pc] & 0x1F], *x, *y, *xw, *yw);
         switch (xyw_memory[*pc])
         {
             // clang-format off
-            /* BRK */ case 0x00: break;
+            /* BRK */ case 0x00: return 0; // Halting execution for now
             /* PSH */ OPC_PSH(0x01);
             /* POP */ OPC_POP(0x02);
-            /* LDR */ OPC_R1(0x03, PUSH(READ(a)));
-            /* LDA */ OPC_S(0x04, READ(us_popw()));
-            /* STA */ OPC_SR1(0x05, xyw_word a = us_popw(), WRITE(a, ARGXY));
-            /* LDP */ OPC_S(0x06, READ(DIRECT_PAGE | us_pop()));
-            /* STP */ OPC_SR1(0x07, xyw_word a = DIRECT_PAGE | us_pop(), WRITE(a, ARGXY));
+            ///* LDR */ OPC_R1(0x03, PUSH(READ(a))); // TBD
+            /* LDB */ OPC_SR1(0x04, , us_push(READB(ARGXY)));
+            /* LDW */ OPC_SR1(0x05, , us_pushw(READW(ARGXY)));
+            /* STB */ OPC_SR2(0x06, WRITEB(b, a));
+            /* STW */ OPC_SR2(0x07, WRITEW(b, a));
             /* INC */ OPC_IDC(0x08, +1);
             /* DEC */ OPC_IDC(0x09, -1);
             /* SHL */ OPC_SR2(0x0A, PUSH(b << a));