diff --git a/Cargo.lock b/Cargo.lock
index 2a13fc4..d0c8d2c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -197,6 +197,7 @@ dependencies = [
  "byteorder",
  "cfg-if 0.1.10",
  "chrono",
+ "either",
  "futures",
  "futures-executor",
  "gdbstub",
@@ -315,6 +316,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ea835d29036a4087793836fa931b08837ad5e957da9e23886b29586fb9b6650"
 
+[[package]]
+name = "either"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
+
 [[package]]
 name = "env_logger"
 version = "0.6.2"
diff --git a/clicky-core/Cargo.toml b/clicky-core/Cargo.toml
index 0bf136b..0778b71 100644
--- a/clicky-core/Cargo.toml
+++ b/clicky-core/Cargo.toml
@@ -17,6 +17,7 @@ bytemuck = "1.2"
 byteorder = "1.3"
 cfg-if = "0.1"
 chrono = "0.4"
+either = "1.9.0"
 log = "0.4"
 num_enum = "0.5"
 static_assertions = "1.1"
diff --git a/clicky-core/src/devices/display/hd66753.rs b/clicky-core/src/devices/display/hd66753.rs
index 9916c57..a7230b0 100644
--- a/clicky-core/src/devices/display/hd66753.rs
+++ b/clicky-core/src/devices/display/hd66753.rs
@@ -4,6 +4,8 @@ use std::sync::{Arc, RwLock};
 
 use crate::gui::RenderCallback;
 
+use either::Either;
+
 const CGRAM_WIDTH: usize = 168;
 const CGRAM_HEIGHT: usize = 132;
 #[allow(dead_code)]
@@ -155,15 +157,22 @@ impl Hd66753 {
             };
 
             let cgram_window = cgram
-                .chunks_exact(EMU_CGRAM_WIDTH * 2 / 8 / 2)
-                .take(height)
-                .flat_map(|row| row.iter().take(CGRAM_WIDTH * 2 / 8 / 2).rev());
+                    .chunks_exact(EMU_CGRAM_WIDTH * 2 / 8 / 2)
+                    .take(height)
+                    .flat_map(|row| {
+                        match ireg.sgs {
+                            true => Either::Left(row.iter().take(CGRAM_WIDTH * 2 / 8 / 2)),
+                            false => Either::Right(row.iter().take(CGRAM_WIDTH * 2 / 8 / 2).rev()),
+                        }
+                        
+                     });
 
             // TODO: implement cursor control
 
             let new_buf = cgram_window.flat_map(|w| {
                 // every 16 bits = 8 pixels
-                (0..8).rev().map(move |i| {
+                (0..8).map(move |i| {
+                    let i = if ireg.sgs { i } else { 7 - i };
                     let idx = ((w >> (i * 2)) & 0b11) as usize;
                     if ireg.rev {
                         PALETTE[idx]