diff --git a/patchwork.md b/patchwork.md
index 6826a6680..c90a6de22 100644
--- a/patchwork.md
+++ b/patchwork.md
@@ -155,3 +155,8 @@ Bump JEI/crafttweaker versions
 
 In my defence, they weren't out when I started the 1.15 update.
 ```
+
+``` 
+bf6053906dc6a3c7b0d40d5b097e745dce1f33bc
+Fix TBO norm issues on old GPUs
+```
diff --git a/src/main/java/dan200/computercraft/shared/peripheral/monitor/ClientMonitor.java b/src/main/java/dan200/computercraft/shared/peripheral/monitor/ClientMonitor.java
index 05b5cb99b..5fce19bc1 100644
--- a/src/main/java/dan200/computercraft/shared/peripheral/monitor/ClientMonitor.java
+++ b/src/main/java/dan200/computercraft/shared/peripheral/monitor/ClientMonitor.java
@@ -80,7 +80,7 @@ public final class ClientMonitor extends ClientTerminal {
             GL15.glBufferData(GL31.GL_TEXTURE_BUFFER, 0, GL15.GL_STATIC_DRAW);
             this.tboTexture = GlStateManager.genTextures();
             GL11.glBindTexture(GL31.GL_TEXTURE_BUFFER, this.tboTexture);
-            GL31.glTexBuffer(GL31.GL_TEXTURE_BUFFER, GL30.GL_R8, this.tboBuffer);
+            GL31.glTexBuffer(GL31.GL_TEXTURE_BUFFER, GL30.GL_R8UI, this.tboBuffer);
             GL11.glBindTexture(GL31.GL_TEXTURE_BUFFER, 0);
 
             GlStateManager.bindBuffers(GL31.GL_TEXTURE_BUFFER, 0);
diff --git a/src/main/resources/assets/computercraft/shaders/monitor.frag b/src/main/resources/assets/computercraft/shaders/monitor.frag
index b0b7b49ed..f19a6a9eb 100644
--- a/src/main/resources/assets/computercraft/shaders/monitor.frag
+++ b/src/main/resources/assets/computercraft/shaders/monitor.frag
@@ -6,7 +6,7 @@
 uniform sampler2D u_font;
 uniform int u_width;
 uniform int u_height;
-uniform samplerBuffer u_tbo;
+uniform usamplerBuffer u_tbo;
 uniform vec3 u_palette[16];
 
 in vec2 f_pos;
@@ -30,9 +30,9 @@ void main() {
     vec2 outside = step(vec2(0.0, 0.0), vec2(cell)) * step(vec2(cell), vec2(float(u_width) - 1.0, float(u_height) - 1.0));
     float mult = outside.x * outside.y;
 
-    int character = int(texelFetch(u_tbo, index).r * 255.0);
-    int fg = int(texelFetch(u_tbo, index + 1).r * 255.0);
-    int bg = int(texelFetch(u_tbo, index + 2).r * 255.0);
+    int character = int(texelFetch(u_tbo, index).r);
+    int fg = int(texelFetch(u_tbo, index + 1).r);
+    int bg = int(texelFetch(u_tbo, index + 2).r);
 
     vec2 pos = (term_pos - corner) * vec2(FONT_WIDTH, FONT_HEIGHT);
     vec4 img = texture(u_font, (texture_corner(character) + pos) / 256.0);