diff --git a/build/misc.tcl b/build/misc.tcl
index b8ae6c8a..88d84ed5 100644
--- a/build/misc.tcl
+++ b/build/misc.tcl
@@ -701,6 +701,10 @@ expect ":KILL"
 respond "*" ":midas sys2;ts comify_sysen3;comify\r"
 expect ":KILL"
 
+# CRC
+respond "*" ":midas sys3;ts crc_gren; crc\r"
+expect ":KILL"
+
 # TMPKIL
 respond "*" ":midas sys2;ts tmpkil_syseng;tmpkil\r"
 expect ":KILL"
diff --git a/doc/programs.md b/doc/programs.md
index 8e97a67c..ba79097a 100644
--- a/doc/programs.md
+++ b/doc/programs.md
@@ -39,6 +39,7 @@
 - COMPLR, Lisp compiler.
 - COMSAT, mail server.
 - CMD, DDT subroutines.
+- CRC, compute file CRC.
 - CREATE, creates a text file in your home directory from console input.
 - CROCK, analog watch.
 - CROSS, cross assembler for micros.
diff --git a/src/gren/crc.70 b/src/gren/crc.70
new file mode 100644
index 00000000..329dc2c5
Binary files /dev/null and b/src/gren/crc.70 differ