From 2300d2813a524cbfeabac794335e7abe99263df6 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Tue, 29 Dec 2015 23:10:50 -0500
Subject: initial commit

---
 timed_getch.s | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 timed_getch.s

(limited to 'timed_getch.s')

diff --git a/timed_getch.s b/timed_getch.s
new file mode 100644
index 0000000..8675290
--- /dev/null
+++ b/timed_getch.s
@@ -0,0 +1,26 @@
+
+ .export _timed_getch, _set_jiffy_timer
+ .import _cgetc
+
+_set_jiffy_timer:
+ sei
+ sta 540
+ stx 541
+ cli
+ rts
+
+_timed_getch:
+ jsr _set_jiffy_timer
+wait4key:
+ lda 540
+ ora 541
+ beq done
+ ldx 764
+ inx
+ beq wait4key
+ jmp _cgetc
+
+done:
+ lda #$ff ; return -1
+ tax
+ rts
-- 
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