From 7c0f9d0477861bfe0356be3a538b89adcc8034ea Mon Sep 17 00:00:00 2001
From: Computer construction kit SmartyKit
 <42343604+smartykit@users.noreply.github.com>
Date: Mon, 2 May 2022 20:07:14 +0300
Subject: [PATCH] Added demo of 6502 'Hello, World!' for a runtime

Text pointer with 'Hello, World!' string is located at RAM and string could be changed during the runtime. Uses functions ECHO and RESET of Woz OS from Apple-1, so could be easily run in emulator.
---
 helloworld-wozos.asm | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 helloworld-wozos.asm

diff --git a/helloworld-wozos.asm b/helloworld-wozos.asm
new file mode 100644
index 0000000..e40578a
--- /dev/null
+++ b/helloworld-wozos.asm
@@ -0,0 +1,25 @@
+;printing 'Hello, World!' at a runtime demo
+;More about 'Hello, World!' program: https://en.wikipedia.org/wiki/%22Hello,_World!%22_program
+	
+RESET = $FF00
+ECHO = $FFEF
+
+TXTPTR = $1000
+
+.org $1000
+	.byte $0d
+	.ASCII  "Hello, World!"
+	.byte $0d
+	.byte $00
+
+.org $2000
+	LDX #00
+PRINT_CHAR:
+	LDA TXTPTR,X
+	BEQ END_PRINT	;end printing at the end of the string (\n=0)
+	JSR ECHO
+	INX
+	JMP PRINT_CHAR
+END_PRINT:
+	JMP RESET	;return to Woz Monitor
+