From 6eb02b3b586b8bc604c643e2ccc1ff09394f72a3 Mon Sep 17 00:00:00 2001
From: xamidev <121681048+xamidev@users.noreply.github.com>
Date: Wed, 23 Oct 2024 20:25:09 +0200
Subject: [PATCH] fix doc + add 8 regs

---
 README.md | 6 ++++--
 cpu.c     | 6 +++---
 cpu.h     | 2 +-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 54b960d..7b4ee72 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ make
 
 - 8-bit processing unit
 - RISC (reduced instruction set computer)
-- 4 general purpose registers (labeled R0 to R3)
+- 8 general purpose registers (labeled Rx)
 - 1 input port, 1 output port (via getchar and putchar)
 - Turing-completeness: bitwise and arithmetic operations
 
@@ -33,9 +33,11 @@ MOV RX, RY
 ; Put value X in register RX
 PUT RX, X
 
-; Arithmetic addition and substraction stored in RX
+; Arithmetic operations. Result stored in RX
 ADD RX, RY
 SUB RX, RY
+MUL RX, RY
+DIV RX, RY
 
 ; Bitwise operations stored in RX
 OR RX, RY
diff --git a/cpu.c b/cpu.c
index 7f92d2f..48d6558 100644
--- a/cpu.c
+++ b/cpu.c
@@ -196,10 +196,10 @@ void cpu_run()
 void cpu_dump()
 {
 	printf("\n*** CPU state dump ***\nPC: 0x%x\nEqual flag: %d\nHalted: %d\n\n", cpu.pc, cpu.equal_flag, cpu.halted);
-	
-	for (size_t i=0; i<NUM_REGISTERS; i++)
+
+	for (size_t i=1; i<NUM_REGISTERS; i+=2)
 	{
-		printf("R%lu: 0x%x\n", i, cpu.reg[i]);
+		printf("R%lu: 0x%04x  R%lu: 0x%04x\n", i, cpu.reg[i], i+1, cpu.reg[i+1]);
 	}
 	puts("");
 }
diff --git a/cpu.h b/cpu.h
index 1d0d4c5..4e650d9 100644
--- a/cpu.h
+++ b/cpu.h
@@ -2,7 +2,7 @@
 #define CPU_H
 
 #define MEM_SIZE	256
-#define NUM_REGISTERS	4
+#define NUM_REGISTERS	8
 #define BUF_MAX     256
 
 /*