Fixed bugs. 8 bit prime Sieve demo.

Programs/Libraries/print.asm

@@ -131,3 +131,20 @@ DecimalValue:
   0x00        ; The ones place.
   0x00        ; The tens place.
   0x00        ; The hundreds place.
+
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Programs/primeSieve/8bitSieve.asm

@@ -0,0 +1,63 @@
+; This is an implementation of The Sieve of Eratosthenes that finds all the primes between 2 and 255.
+
+#Include ../Libraries/print.asm
+
+#Program
+
+start:
+  ; Search the list until we find a prime.
+  SETD DataTop
+  CCF ; Clear the carry flag. In later cycles, the carry flag will be set at the end of the next loop. We'll want it cleared.
+  INIA 0x00
+  INIB 0x00
+ findPrimeLoop:
+  LDB ; Load an element into B.
+  BRB foundPrime ; If it's zero, it's a prime.
+  INCA ; Increment A, our index.
+  INCD ; Increment the Data Pointer.
+  BRA end ; If A becomes zero, we've looked through the whole list without finding another prime.
+  BRI findPrimeLoop ; Keep searching for the next prime.
+   foundPrime:
+    ; If we've found a prime, we should print it and mark it off the list so we don't print it again.
+    CALL printByteDecimal ; A contains our prime, so we can just call the print subroutine.
+    CALL blankSpace ; Put a space afterward to keep things easy to read.
+    INIB 0x01 ; Set B to 1.
+    STB ; Mark this prime off the list.
+     markMultiples:
+      ; Now, we mark each multiple of this prime as nonprime until we reach the end of the list.
+      PSHD ; Save the Data Pointer to the stack.
+      POPB ; Pop its low byte into B.
+      ADD ; Add them together.
+      PSHQ ; Store the result back onto the stack.
+      POPD ; Pop the modified address into the Data Pointer.
+      INIB 0x01 ; Set B to 1.
+      STB ; Store B to mark the value as nonprime.
+      BRC start ; If the previous add overflowed, the next nonprime is outside the range of our list, so start over with a new prime.
+      BRI markMultiples ; Otherwise, loop again to mark the next multiple as nonprime.
+ end:
+  CALL lineFeed ; Print a linefeed to make it look nice.
+  HALT ; The program is done, we found all the primes!
+
+
+
+
+#Data
+
+; The table of our prime candidates.
+DataTop:
+0x01 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Source/Assembler/assembly.c

@@ -68,7 +68,6 @@ Instruction instruction_set[] = {
     // Input Operations:
     {0xE0, "INA"},
     {0xE1, "INB"},
-    {0xE2, "IND"},
     // Special Operations:
     {0xF0, "NOP"},
     {0xFF, "HALT"}

Source/Emulator/cpu.c

@@ -276,11 +276,12 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
         break;
         case 0x33:
             // PSHD - Push the Data Pointer Address to the Stack.
-            // Order, low byte, high byte
+            // Order, high byte, low byte
-            cpu->Data[cpu->StackPointer] = cpu->DataPointer & 0xFF;
+            // This ordering makes it easier to add offsets with register math.
-            cpu->StackPointer--;
             cpu->Data[cpu->StackPointer] = (cpu->DataPointer >> 8) & 0xFF;
             cpu->StackPointer--;
+            cpu->Data[cpu->StackPointer] = cpu->DataPointer & 0xFF;
+            cpu->StackPointer--;
         break;
         case 0x34:
             // POPA - Pop A from the Stack.
@@ -296,9 +297,9 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
         case 0x36:
             // POPD - Pop Data Address from the Stack.
             cpu->StackPointer++;
-            cpu->DataPointer = (uint16_t)cpu->Data[cpu->StackPointer] << 8;
+            cpu->DataPointer = (uint16_t)cpu->Data[cpu->StackPointer];
             cpu->StackPointer++;
-            cpu->DataPointer |= (uint16_t)cpu->Data[cpu->StackPointer];
+            cpu->DataPointer |= (uint16_t)cpu->Data[cpu->StackPointer] << 8;
         break;
         //
         // 4x - Data Operations:
@@ -381,11 +382,6 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
             cpu->ProgramCounter++;
             cpu->B = InputHandler(cpu->Program[cpu->ProgramCounter]);
         break;
-        case 0xE2:
-            // IND - Read an Input to Data Memory.
-            cpu->ProgramCounter++;
-            cpu->Data[cpu->DataPointer] = InputHandler(cpu->Program[cpu->ProgramCounter]);
-        break;
         //
         // Fx - Special Operations:
         //

SplitBit Programming Manual.md

@@ -62,10 +62,10 @@ Hex Code | Mnemonic | Description
 30 | PSHQ | Stores Q into Data Memory at the location referenced by the Stack Pointer then decrements the Stack Pointer.
 31 | PSHA | Stores A into Data Memory at the location referenced by the Stack Pointer then decrements the Stack Pointer.
 32 | PSHB | Stores B into Data Memory at the location referenced by the Stack Pointer then decrements the Stack Pointer.
-33 | PSHD | Stores the Data Pointer to the next two bytes in the stack, decrements the Stack Pointer by two.
+33 | PSHD | Stores the Data Pointer to the stack, with the low byte on top. Increments the Stack Pointer by two.
 34 | POPA | Reads the location referenced by the Stack Pointer from Data Memory into A then increments the Stack Pointer.
 35 | POPB | Reads the location referenced by the Stack Pointer from Data Memory into B then increments the Stack Pointer.
-36 | POPD | Restores the Program Counter from the top two bytes in the stack, increments the Stack Pointer by two.
+36 | POPD | Restores the Program Counter from the stack, increments the Stack Pointer by two.
 
 ### Data Operations: 10 Instructions
 Hex Code | Mnemonic | Description
@@ -89,12 +89,11 @@ D0 | OUTQ | Writes the value of Q to an Output specified by the next byte of Pro
 D1 | OUTA | Writes the value of A to an Output specified by the next byte of Program Memory.
 D2 | OUTB | Writes the value of B to an Output specified by the next byte of Program Memory.
 
-### Input Operations: 3 Instructions
+### Input Operations: 2 Instructions
 Hex Code | Mnemonic | Description
 -- | -- | --
 E0 | INA | Writes the value of an Input to A. The input port is specified the next byte of Program Memory.
 E1 | INB | Writes the value of an Input to B. The input port is specified the next byte of Program Memory.
-E2 | IND | Writes the value of an Input to Data Memory at the location referenced by the Data Pointer. The input port is specified by the next byte of Program Memory.
 
 ### Special Operations: 2 Instructions
 Hex Code | Mnemonic | Description