From 7587f1fbba4559c0cae890f02c72077e06d72241 Mon Sep 17 00:00:00 2001
From: lynchaj <86925539+lynchaj@users.noreply.github.com>
Date: Mon, 19 Jul 2021 14:46:33 -0400
Subject: [PATCH 1/2] Update dbgmon.asm

---
 Source/Apps/ramtest/dbgmon.asm | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/Source/Apps/ramtest/dbgmon.asm b/Source/Apps/ramtest/dbgmon.asm
index 393fafd5..bcf8b323 100644
--- a/Source/Apps/ramtest/dbgmon.asm
+++ b/Source/Apps/ramtest/dbgmon.asm
@@ -908,6 +908,31 @@ FILL_MEM:
 
 DORAMTEST:
 
+; VERIFY DATA BUS FUNCTIONALITY BEFORE STARTING MEMORY TEST
+	LD	A,$80			; FIRST 32KB PAGE ONLY
+	LD	(PAGE_NUM),A		; STORE WORKING PAGE NUMBER
+	OUT	(MPCL_ROM),A		; SWITCH OUT LOWER 32KB ROM PAGE
+	OUT	(MPCL_RAM),A		; SWITCH IN LOWER 32KB RAM PAGE
+	LD	A,$00			; INITIALIZE A TO 0
+
+DATABUSCHECK:
+	LD	($0000),A		; WRITE TO LOWEST RAM ADDRESS
+	LD	C,($0000)		; READ VALUE FROM LOWEST RAM ADDRESS
+	CP	C			; IS IT SAME AS WRITTEN?
+	JP	NZ,DATABUSFAIL		; DATA BUS FAIL HANDLER ROUTINE
+	INC	A			; GET NEXT VALUE
+	JP	NZ,DATABUSCHECK		; REPEAT FOR ALL 256 VALUES
+	
+DATABUSFAIL:
+	PUSH	A			; STORE FAILED VALUE
+	LD	HL,TXT_DATA_BUS_FAIL	; POINT AT DATA BUS FAIL TEXT
+	CALL	MSG			; PRINT DATA BUS FAIL LABEL
+	POP	A			; RETRIEVE FAILED VALUE
+	CALL	HXOUT			; SHOW VALUE THAT FAILED
+	LD	HL,TCRLF		; CR & LF
+	CALL	MSG			; DISPLAY IT
+	JP	SERIALCMDLOOP		; AND BACK TO COMMAND LOOP
+
 MEMSIZELOOP:
 	LD	HL,TXT_RAM_TEST_MAIN	; POINT AT RAM TEST MAIN MENU TEXT
 	CALL	MSG			; PRINT MENU TEXT LABEL
@@ -1139,6 +1164,11 @@ TXT_RAM_FAIL:
 	.DB   "RAM FAIL, 32KB PAGE NUMBER: "
 	.DB   CR,LF,ENDT
 
+TXT_DATA_BUS_FAIL:
+	.DB   CR,LF
+	.DB   "DATA BUS FAIL, VALUE ="
+	.DB   ENDT
+
 TXT_SKIP_16:
 	.DB   CR,LF
 	.DB   "SKIPPING PAGE 0F "

From 3349f682136e65c25e57cc4cfe37202bea139351 Mon Sep 17 00:00:00 2001
From: lynchaj <86925539+lynchaj@users.noreply.github.com>
Date: Mon, 19 Jul 2021 15:37:33 -0400
Subject: [PATCH 2/2] Update dbgmon.asm

---
 Source/Apps/ramtest/dbgmon.asm | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Source/Apps/ramtest/dbgmon.asm b/Source/Apps/ramtest/dbgmon.asm
index bcf8b323..f5d5c79f 100644
--- a/Source/Apps/ramtest/dbgmon.asm
+++ b/Source/Apps/ramtest/dbgmon.asm
@@ -919,9 +919,12 @@ DATABUSCHECK:
 	LD	($0000),A		; WRITE TO LOWEST RAM ADDRESS
 	LD	C,($0000)		; READ VALUE FROM LOWEST RAM ADDRESS
 	CP	C			; IS IT SAME AS WRITTEN?
-	JP	NZ,DATABUSFAIL		; DATA BUS FAIL HANDLER ROUTINE
-	INC	A			; GET NEXT VALUE
+	JP	NZ,DATABUSFAIL		; NO? DATA BUS FAIL HANDLER ROUTINE
+	INC	A			; YES, GET NEXT VALUE
 	JP	NZ,DATABUSCHECK		; REPEAT FOR ALL 256 VALUES
+	LD	HL,TXT_DATA_BUS_PASS	; POINT AT DATA BUS PASS TEXT
+	CALL	MSG			; PRINT DATA BUS PASS LABEL
+	JP	MEMSIZELOOP		; CONTINUE WITH REST OF RAM TEST	
 	
 DATABUSFAIL:
 	PUSH	A			; STORE FAILED VALUE
@@ -1169,6 +1172,11 @@ TXT_DATA_BUS_FAIL:
 	.DB   "DATA BUS FAIL, VALUE ="
 	.DB   ENDT
 
+TXT_DATA_BUS_PASS:
+	.DB   CR,LF
+	.DB   "DATA BUS PASS "
+	.DB   CR,LF,ENDT
+
 TXT_SKIP_16:
 	.DB   CR,LF
 	.DB   "SKIPPING PAGE 0F "