From 9153c5c0700cc9c04ea4095a8b424e0beb3eac05 Mon Sep 17 00:00:00 2001
From: old <techokba@gmail.com>
Date: Sun, 12 Oct 2025 14:32:54 +0100
Subject: [PATCH] feat: add typewriter clock tutorial in x86 assembly

---
 basic/typewriter_clock/Makefile             |  8 +++
 basic/typewriter_clock/README.md            | 13 ++++
 basic/typewriter_clock/typewriter_clock.asm | 71 +++++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 basic/typewriter_clock/Makefile
 create mode 100644 basic/typewriter_clock/README.md 
 create mode 100644 basic/typewriter_clock/typewriter_clock.asm

diff --git a/basic/typewriter_clock/Makefile b/basic/typewriter_clock/Makefile
new file mode 100644
index 0000000..d4865f0
--- /dev/null
+++ b/basic/typewriter_clock/Makefile
@@ -0,0 +1,8 @@
+all: typewriter_clock
+
+typewriter_clock: typewriter_clock.asm
+	nasm -f elf32 typewriter_clock.asm -o typewriter_clock.o
+	ld -m elf_i386 typewriter_clock.o -o typewriter_clock
+
+clean:
+	rm -f *.o typewriter_clock
diff --git a/basic/typewriter_clock/README.md  b/basic/typewriter_clock/README.md 
new file mode 100644
index 0000000..8fef4e9
--- /dev/null
+++ b/basic/typewriter_clock/README.md 	
@@ -0,0 +1,13 @@
+# Typewriter Clock - x86 Assembly Tutorial
+
+## Description
+This is a simple x86 Assembly program that prints the current time in the terminal with a typewriter effect.
+
+## Requirements
+- Linux (tested on Debian/Ubuntu)
+- NASM assembler
+
+## Build and Run
+```bash
+make
+./typewriter_clock
diff --git a/basic/typewriter_clock/typewriter_clock.asm b/basic/typewriter_clock/typewriter_clock.asm
new file mode 100644
index 0000000..dc5c172
--- /dev/null
+++ b/basic/typewriter_clock/typewriter_clock.asm
@@ -0,0 +1,71 @@
+; typewriter_clock.asm - x86 Assembly (Linux ELF32)
+; Typewriter clock: prints current time in terminal
+; Compile: make
+; Run: ./typewriter_clock
+
+section .data
+    msg db "00:00:00", 0       ; placeholder for HH:MM:SS
+    len equ $ - msg
+    newline db 0x0A, 0         ; newline
+
+section .bss
+    timebuf resb 9             ; HH:MM:SS\0
+
+section .text
+global _start
+
+_start:
+.loop:
+    ; get current time from system
+    mov eax, 13               ; sys_time
+    xor ebx, ebx              ; time_t *tloc = NULL
+    int 0x80
+
+    ; simple conversion to HH:MM:SS (simplified)
+    mov ecx, 3600             ; seconds per hour
+    xor edx, edx
+    div ecx                    ; eax/3600 -> quotient=hours, remainder=minutes+seconds
+    add al, '0'
+    mov [timebuf], al
+
+    ; minutes
+    mov eax, edx
+    mov ecx, 60
+    xor edx, edx
+    div ecx
+    add al, '0'
+    mov [timebuf+3], al
+
+    ; seconds
+    mov al, dl
+    add al, '0'
+    mov [timebuf+6], al
+
+    ; print with typewriter effect
+    mov esi, timebuf
+.print_loop:
+    lodsb
+    cmp al, 0
+    je .done
+    mov eax, 4
+    mov ebx, 1
+    mov ecx, esi
+    dec ecx
+    mov edx, 1
+    int 0x80
+
+    ; small delay
+    mov ecx, 50000
+.delay:
+    loop .delay
+    jmp .print_loop
+
+.done:
+    ; new line
+    mov eax, 4
+    mov ebx, 1
+    mov ecx, newline
+    mov edx, 1
+    int 0x80
+
+    jmp .loop