diff --git a/README.md b/README.md
index d32c782..32ae12b 100755
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
-# 1/10/2020 PLASMA 2.0 Developer Preview 3 Available!
+# 1/31/2020 PLASMA 2.0 Developer Preview 4 Available!
 [Download and read the Release Notes](https://github.com/dschmenk/PLASMA/releases)
 
-[Change List](https://github.com/dschmenk/PLASMA/blob/master/doc/Version%202.0.md#changes-in-plasma-for-20-dp-3)
+[Change List](https://github.com/dschmenk/PLASMA/blob/master/doc/Version%202.0.md#changes-in-plasma-for-20-dp-4)
 
 # 4/29/2018 PLASMA 1.2 Available!
 [Download and read the Release Notes](https://github.com/dschmenk/PLASMA/blob/master/doc/Version%201.2.md)
diff --git a/doc/Version 2.0.md b/doc/Version 2.0.md
index 7894a0c..2b67885 100644
--- a/doc/Version 2.0.md	
+++ b/doc/Version 2.0.md	
@@ -1,20 +1,20 @@
-# PLASMA Version 2.0 Developer Preview 3
+# PLASMA Version 2.0 Developer Preview 4
 
 Welcome to PLASMA: the Grand Unifying Platform for the Apple 1, ][, and ///.
 
 Download the five disk images:
 
-[PLASMA 2.0 DP3 800K Full System](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2.2mg?raw=true)
+[PLASMA 2.0 DP4 800K Full System](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2.2mg?raw=true)
 
-[PLASMA 2.0 DP3 System and ProDOS Boot](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-SYS.PO?raw=true)
+[PLASMA 2.0 DP4 System and ProDOS Boot](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-SYS.PO?raw=true)
 
-[PLASMA 2.0 D3P Build Tools](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-BLD.PO?raw=true)
+[PLASMA 2.0 DP4 Build Tools](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-BLD.PO?raw=true)
 
-[PLASMA 2.0 DP3 Demos](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-DEM.PO?raw=true)
+[PLASMA 2.0 DP4 Demos](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-DEM.PO?raw=true)
 
-[PLASMA 2.0 DP3 TCP/IP network modules](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-INET.PO?raw=true)
+[PLASMA 2.0 DP4 TCP/IP network modules](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-INET.PO?raw=true)
 
-[PLASMA 2.0 DP3 Apple /// SOS Boot and SANE floating point modules](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-FPSOS.PO?raw=true)
+[PLASMA 2.0 DP4 Apple /// SOS Boot and SANE floating point modules](https://github.com/dschmenk/PLASMA/blob/master/images/apple/PLASMA2-FPSOS.PO?raw=true)
 
 PLASMA can be run from floppies, System in Drive 1, and Build or Demos in Drive 2. Mass storage is the recommended installation that looks like (replacing HARDISK with your volume name of choice):
 
@@ -116,6 +116,14 @@ There is a [YouTube playlist](https://www.youtube.com/playlist?list=PLlPKgUMQbJ7
 
 - The documentation is sparse and incomplete. Yep, could use your help...
 
+# Changes in PLASMA for 2.0 DP 4
+
+1. Improved editor auto-indenting
+
+2. Compiler fix for terneray operator precedence
+
+3. Machine check for HGR library
+
 # Changes in PLASMA for 2.0 DP 3
 
 1. File manipulation utilities fixed for Apple /// SOS vs ProDOS differences
diff --git a/images/apple/PLASMA2-SYS.PO b/images/apple/PLASMA2-SYS.PO
index 64396ce..58e611f 100755
Binary files a/images/apple/PLASMA2-SYS.PO and b/images/apple/PLASMA2-SYS.PO differ
diff --git a/images/apple/PLASMA2.2mg b/images/apple/PLASMA2.2mg
index 359f70d..db34e4f 100644
Binary files a/images/apple/PLASMA2.2mg and b/images/apple/PLASMA2.2mg differ