diff --git a/src/boot/sysobj.reb b/src/boot/sysobj.reb
index 09240c78dd..e55d3acf29 100644
--- a/src/boot/sysobj.reb
+++ b/src/boot/sysobj.reb
@@ -149,6 +149,7 @@ options: object [  ; Options supplied to REBOL during startup
 
 	binary-base: 16    ; Default base for FORMed binary values (64, 16, 2)
 	decimal-digits: 15 ; Max number of decimal digits to print.
+	probe-limit: 16000 ; Max probed output size, 0 means no limit
 	module-paths: [%./]
 	default-suffix: %.reb ; Used by IMPORT if no suffix is provided
 	file-types: []
diff --git a/src/core/n-io.c b/src/core/n-io.c
index 3ecda8f297..908e901738 100644
--- a/src/core/n-io.c
+++ b/src/core/n-io.c
@@ -131,15 +131,15 @@ static REBSER *Read_All_File(char *fname)
 {
 	REBVAL *val = D_ARG(1);
 	REB_MOLD mo = {0};
-	REBINT  len = -1; // no limit
+	REBINT  len = NO_LIMIT;
 
 	if (D_REF(3)) SET_FLAG(mo.opts, MOPT_MOLD_ALL);
 	if (D_REF(4)) SET_FLAG(mo.opts, MOPT_INDENT);
 	if (D_REF(5)) {
 		if (VAL_INT64(D_ARG(6)) > (i64)MAX_I32)
 			len = MAX_I32;
-		else if (VAL_INT64(D_ARG(6)) < 0)
-			len = 0;
+		else if (VAL_INT64(D_ARG(6)) <= 0)
+			len = NO_LIMIT;
 		else
 			len = VAL_INT32(D_ARG(6));
 	}
diff --git a/src/mezz/base-debug.reb b/src/mezz/base-debug.reb
index ef409dd507..15da1c18f4 100644
--- a/src/mezz/base-debug.reb
+++ b/src/mezz/base-debug.reb
@@ -19,8 +19,14 @@ REBOL [
 probe: func [
 	{Debug print a molded value and returns that same value.}
 	value [any-type!]
+	/local len
 ][
-	print mold :value
+	len: system/options/probe-limit
+	print either 0 < len [
+		ellipsize (mold/part :value len + 1) len
+	][
+		mold :value
+	]
 	:value
 ]
 
@@ -33,7 +39,7 @@ probe: func [
 			word? :name
 			path? :name
 		][
-			prin ajoin ["^[[1;32;49m" mold :name "^[[0m: ^[[32m"] 
+			prin ajoin ["^[[1;32m" mold :name "^[[0m: ^[[32m"] 
     		prin either value? :name [mold/all get/any :name] ["#[unset!]"]
     		print "^[[0m"
 		]
@@ -43,15 +49,15 @@ probe: func [
 					word? :word
 					path? :word
 				][
-					prin ajoin ["^[[1;32;49m" mold :word "^[[0m: ^[[32m"] 
+					prin ajoin ["^[[1;32m" mold :word "^[[0m: ^[[32m"] 
 					prin either value? :word [mold/all get/any :word]["#[unset!]"]
 					print "^[[0m"
 				][
-					print ajoin ["^[[1;32;49m" mold/all word "^[[0m"]
+					print ajoin ["^[[1;32m" mold/all word "^[[0m"]
 				]
 			]
 		]
-		true [print ajoin ["^[[1;32;49m" mold/all :name "^[[0m"]]
+		true [print ajoin ["^[[1;32m" mold/all :name "^[[0m"]]
 	]
 	exit
 ]
diff --git a/src/mezz/base-series.reb b/src/mezz/base-series.reb
index edf46cdea0..ac68c1893b 100644
--- a/src/mezz/base-series.reb
+++ b/src/mezz/base-series.reb
@@ -44,3 +44,27 @@ reform: func [
 ][
 	form reduce :value
 ]
+
+ellipsize: func [
+	"Truncate and add ellipsis if str is longer than len"
+	str [string!] "(modified)"
+	len [integer!] "Max length"
+	/one-line "Escape line breaks"
+	/local chars
+][
+	if one-line [
+		chars: #[bitset! [not bits #{0024}]]
+		parse str [
+			any [
+				some chars
+				| change #"^/" "^^/"
+				| change #"^M" "^^M"
+			]
+		]
+	]
+	if len < length? str [
+		append clear skip str (len - 3) "..."
+	]
+
+	str
+]
diff --git a/src/mezz/mezz-help.reb b/src/mezz/mezz-help.reb
index b2dcccbc66..9fe072fcee 100644
--- a/src/mezz/mezz-help.reb
+++ b/src/mezz/mezz-help.reb
@@ -71,15 +71,6 @@ import module [
 		buffer: insert buffer form reduce value
 	]
 
-	clip-str: func [str] [
-		; Keep string to one line.
-		unless string? str [str: mold/part/flat str max-desc-width]
-		replace/all str LF "^^/"
-		replace/all str CR "^^M"
-		if (length? str) > (max-desc-width - 1) [str: append copy/part str max-desc-width "..."]
-		str
-	]
-
 	interpunction: charset ";.?!"
 	dot: func[value [string!]][
 		unless find interpunction last value [append value #"."]
@@ -116,7 +107,8 @@ import module [
 			;none?         :val [ mold/all val]
 			true [:val]
 		]
-		clip-str val
+		unless string? val [val: mold/part/flat val max-desc-width]
+		ellipsize/one-line val max-desc-width - 1
 	]
 
 	form-pad: func [val size] [