diff --git a/build/misc.tcl b/build/misc.tcl
index a703200c..e35e2086 100644
--- a/build/misc.tcl
+++ b/build/misc.tcl
@@ -19,6 +19,15 @@ respond "*" ":midas sys1;ts salv_system;salv\r"
 respond "time-sharing?" "y\r"
 expect ":KILL"
 
+# system gen
+respond "*" ":midas /t dsk0:.;@ sysgen_syseng; system gen\r"
+respond "with ^C" "PI==4\r"
+respond "\n" "TTY==120\r"
+respond "\n" "DC==200\r"
+respond "\n" "UTC==210\r"
+respond "\n" "UTS==214\r\003"
+expect ":KILL"
+
 respond "*" ":midas sys3;ts syslod_sysen1;syslod\r"
 expect ":KILL"
 
diff --git a/doc/programs.md b/doc/programs.md
index 21d2cea6..09cf301c 100644
--- a/doc/programs.md
+++ b/doc/programs.md
@@ -211,6 +211,7 @@
 - SYSCHK, check up on system job.
 - SYSLOD, system load histogram.
 - SYSMSG, displays system messages.
+- SYSTEM GEN, low level DECtape formatting.
 - RABBIT, Scheme compiler.
 - TAGS, generate tags table for sources.
 - TALK/WHO/WHOJ/WHOM/USERS, list users.
diff --git a/src/syseng/system.gen b/src/syseng/system.gen
index 638b35b9..39c8bec7 100644
Binary files a/src/syseng/system.gen and b/src/syseng/system.gen differ