From 4ff7888bdc2b243d1f3515da6b112273f8f2e98b Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Tue, 3 Jun 2025 17:13:17 -0700
Subject: [PATCH] Fit RTC Detection, Issue #566

Corrected DSRTC and BQRTC drivers to properly restore the value of the NVRAM byte used for presence detection.

Thanks and credit to @MartinGieseCelonis for finding this.
---
 Source/HBIOS/dsrtc.asm  | 1 +
 Source/HBIOS/rp5rtc.asm | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/Source/HBIOS/dsrtc.asm b/Source/HBIOS/dsrtc.asm
index ecce36ee..81015be0 100644
--- a/Source/HBIOS/dsrtc.asm
+++ b/Source/HBIOS/dsrtc.asm
@@ -482,6 +482,7 @@ DSRTC_DETECT:
 DSRTC_DETECT1:
 	PUSH	AF			; SAVE STATUS
 	LD	A,(DSRTC_TEMP)		; GET SAVED VALUE
+	LD	E,A			; TO E
 	LD	C,30			; NVRAM INDEX 30
 	CALL	DSRTC_SETBYT		; SAVE IT
 	POP	AF			; RECOVER STATUS
diff --git a/Source/HBIOS/rp5rtc.asm b/Source/HBIOS/rp5rtc.asm
index 2a7b99a6..b86ddf70 100644
--- a/Source/HBIOS/rp5rtc.asm
+++ b/Source/HBIOS/rp5rtc.asm
@@ -136,7 +136,7 @@ RP5RTC_DETECT:
 
 RP5RTC_DETECT1:
 	PUSH	AF			; SAVE STATUS
-	LD	A, L			; GET SAVED VALUE
+	LD	E, L			; GET SAVED VALUE
 	LD	C, 0 			; NVRAM INDEX 0
 	CALL	RP5RTC_SETBYT		; SAVE IT
 	POP	AF			; RECOVER STATUS