diff --git a/src/disp/disp_qy.mjs b/src/disp/disp_qy.mjs
index 9d4c283..1044cbb 100644
--- a/src/disp/disp_qy.mjs
+++ b/src/disp/disp_qy.mjs
@@ -416,18 +416,20 @@ let QyDisplay = class extends RootDisplay {
 				};
 			};
 			for (let tch = 0; tch < 8; tch ++) { // target channel
-				let rch = curSeg * 8 + tch,
+				let rch = (curSeg << 3) + tch,
 				textTarget = 1;
 				upThis.qyRsrc.getBm("CTabOff")?.render((e, x, y) => {
 					upThis.#nmdb[preCal + 12 * tch + x + y * 128] = e;
 				});
-				let cVelo = Math.floor(sum.strength[rch] / 51);
-				upThis.#renderFill(31 + 12 * tch, preCalY + 11 - cVelo, 9, cVelo + 1);
-				if (this.#ch == rch) {
-					textTarget = 0;
-					upThis.#renderFill(31 + 12 * tch, preCalY, 9, 5);
-					if (mixerView) {
-						upThis.#renderFill(30 + 12 * tch, preCalY + 14, 13, 8);
+				if (sum.chInUse[rch]) {
+					let cVelo = Math.floor(sum.strength[rch] / 51);
+					upThis.#renderFill(31 + 12 * tch, preCalY + 11 - cVelo, 9, cVelo + 1);
+					if (this.#ch == rch) {
+						textTarget = 0;
+						upThis.#renderFill(31 + 12 * tch, preCalY, 9, 5);
+						if (mixerView) {
+							upThis.#renderFill(30 + 12 * tch, preCalY + 14, 13, 8);
+						};
 					};
 				};
 				if (rch < 19) {
diff --git a/src/state/index.mjs b/src/state/index.mjs
index 803be28..c9a64f8 100644
--- a/src/state/index.mjs
+++ b/src/state/index.mjs
@@ -3983,7 +3983,7 @@ let OctaviaDevice = class extends CustomEventSource {
 			let desiredByteTail = boundOff + workArr.length,
 			desiredLengthHead = boundOff * 6 - ((boundOff * 2428 >> 16) << 1),
 			desiredLengthTail = desiredByteTail * 6 - ((desiredByteTail * 2428 >> 16) << 1); // That's an integer division of 27, then a multiple of 2.
-			if (desiredLengthHead >= 640) {
+			if (desiredLengthHead > 640) {
 				console.warn(`SC-8850 partial screen dump out of bounds: invalid buffer range.\n`, msg);
 				return;
 			};
@@ -4005,6 +4005,7 @@ let OctaviaDevice = class extends CustomEventSource {
 			let byteOffset = bundleId * 108 + boundOff,
 			offset = byteOffset * 6 - ((byteOffset * 2428 >> 16) << 1); // Used for emitting events than for internal processing.
 			upThis.dispatchEvent("screen", {type: "sc8850", offset, data: screenBuffer});
+			getDebugState() && console.debug(`SC-8850 screen dump: bundle ${bundleId + 1}, range ${desiredLengthHead}~${desiredLengthTail}`);
 		});
 		// GS Part setup
 		// I wanted this to also be written in a circular structure