From b9a251bb1f60506328ebadddba678260b66eeaf5 Mon Sep 17 00:00:00 2001
From: Wayne Warthen <wwarthen@gmail.com>
Date: Sat, 29 Nov 2025 17:03:42 -0800
Subject: [PATCH] Minor Improvement in DS12RTC Driver

- Refactored the Update-In-Progress checks to reduce code size and improve checking accuracy.
---
 Source/HBIOS/ds12rtc.asm | 44 +++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/Source/HBIOS/ds12rtc.asm b/Source/HBIOS/ds12rtc.asm
index 516aa20c..e59db42e 100644
--- a/Source/HBIOS/ds12rtc.asm
+++ b/Source/HBIOS/ds12rtc.asm
@@ -252,64 +252,70 @@ DS12RTC_DETECT:
 ; READ CLOCK DATA INTO BUFFER AT HL (YYMMDDHHMMSS)
 ;
 DS12RTC_RDCLK:
-	LD	D,H			; RESET DE
-	LD	E,L			; ... IN CASE OF RESTART
+	LD	E,0			; CLEAR UIP FLAG
+	PUSH	HL			; SAVE IN CASE OF RESTART
 	LD	C,$09			; START WITH YEAR REG
 	CALL	DS12RTC_RDCLK1		; DO YEAR (REG $09)
-	JR	NZ,DS12RTC_RDCLK	; RESTART IF UIP DETECTED
 	CALL	DS12RTC_RDCLK1		; DO MONTH (REG $08)
-	JR	NZ,DS12RTC_RDCLK	; RESTART IF UIP DETECTED
 	CALL	DS12RTC_RDCLK1		; DO DAY OF MONTH (REG $07)
-	JR	NZ,DS12RTC_RDCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP DAY OF WEEK (REG $06)
 	DEC	C			; SKIP HOURS ALARM (REG $05)
 	CALL	DS12RTC_RDCLK1		; DO HOUR (REG $04)
-	JR	NZ,DS12RTC_RDCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP MINUTES ALARM (REG $03)
 	CALL	DS12RTC_RDCLK1		; DO MINUTES (REG $02)
-	JR	NZ,DS12RTC_RDCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP SECONDS ALARM (REG $01)
 	CALL	DS12RTC_RDCLK1		; DO SECONDS (REG $00)
+	POP	HL			; RESTORE BUF PTR
+	LD	A,E			; UIP FLAG TO ACCUM
+	OR	A			; TEST IT
+	JR	NZ,DS12RTC_RDCLK	; IF UIP WAS FLAGGED, TRY AGAIN
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET				; DONE
 ;	
 DS12RTC_RDCLK1:
+	CALL	DS12RTC_UIP		; CHECK FOR UPDATE IN PROGRESS
+	JR	Z,DS12RTC_RDCLK2	; IF NO UIP, SKIP AHEAD
+	INC	E			; FLAG UIP OCCURRED
+DS12RTC_RDCLK2:
 	CALL	DS12RTC_RDREG		; GET IT
-	LD	(DE),A			; STORE IN BUF
-	INC	DE			; BUMP BUF PTR
+	LD	(HL),A			; STORE IN BUF
+	INC	HL			; BUMP BUF PTR
 	DEC	C			; DEC REGISTER
-	JR	DS12RTC_UIP		; RETURN VIA CHECK FOR UPDATE IN PROGRESS
+	RET
 ;
 ; WRITE CLOCK DATA FROM BUFFER AT HL
 ;
 DS12RTC_WRCLK:
-	LD	D,H			; RESET DE
-	LD	E,L			; ... IN CASE OF RESTART
+	LD	E,0			; CLEAR UIP FLAG
+	PUSH	HL			; SAVE IN CASE OF RESTART
 	LD	C,$09			; START WITH YEAR REG
 	CALL	DS12RTC_WRCLK1		; DO YEAR (REG $09)
-	JR	NZ,DS12RTC_WRCLK	; RESTART IF UIP DETECTED
 	CALL	DS12RTC_WRCLK1		; DO MONTH (REG $08)
-	JR	NZ,DS12RTC_WRCLK	; RESTART IF UIP DETECTED
 	CALL	DS12RTC_WRCLK1		; DO DAY OF MONTH (REG $07)
-	JR	NZ,DS12RTC_WRCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP DAY OF WEEK (REG $06)
 	DEC	C			; SKIP HOURS ALARM (REG $05)
 	CALL	DS12RTC_WRCLK1		; DO HOUR (REG $04)
-	JR	NZ,DS12RTC_WRCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP MINUTES ALARM (REG $03)
 	CALL	DS12RTC_WRCLK1		; DO MINUTES (REG $02)
-	JR	NZ,DS12RTC_WRCLK	; RESTART IF UIP DETECTED
 	DEC	C			; SKIP SECONDS ALARM (REG $01)
 	CALL	DS12RTC_WRCLK1		; DO SECONDS (REG $00)
+	POP	HL			; RESTORE BUF PTR
+	LD	A,E			; UIP FLAG TO ACCUM
+	OR	A			; TEST IT
+	JR	NZ,DS12RTC_WRCLK	; IF UIP WAS FLAGGED, TRY AGAIN
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET				; DONE
 ;	
 DS12RTC_WRCLK1:
-	LD	A,(DE)			; GET VALUE
+	CALL	DS12RTC_UIP		; CHECK FOR UPDATE IN PROGRESS
+	JR	Z,DS12RTC_WRCLK2	; IF NO UIP, SKIP AHEAD
+	INC	E			; FLAG UIP OCCURRED
+DS12RTC_WRCLK2:
+	LD	A,(HL)			; GET VALUE
 	CALL	DS12RTC_WRREG		; WRITE IT
-	INC	DE			; BUMP BUF PTR
+	INC	HL			; BUMP BUF PTR
 	DEC	C			; DEC REGISTER
 	JR	DS12RTC_UIP		; RETURN VIA CHECK FOR UPDATE IN PROGRESS
 ;