From 7604f977247896c81af0c824a9f418791d9804cb Mon Sep 17 00:00:00 2001
From: Lars Brinkhoff <lars@nocrew.org>
Date: Tue, 31 Jul 2018 22:42:22 +0200
Subject: [PATCH] Fix Lunar Lander to assemble with PALX.

- Add definitions for registers.
- Change starting location from 0 to 400.
---
 build/misc.tcl                   |  4 ++++
 doc/programs.md                  |  1 +
 src/gt40/{gtlem.mac => gtlem.91} | 14 ++++++++++++++
 3 files changed, 19 insertions(+)
 rename src/gt40/{gtlem.mac => gtlem.91} (99%)

diff --git a/build/misc.tcl b/build/misc.tcl
index e29020cc..498d1c05 100644
--- a/build/misc.tcl
+++ b/build/misc.tcl
@@ -1046,6 +1046,10 @@ expect ":KILL"
 respond "*" ":palx gt40;bootvt\r"
 expect ":KILL"
 
+# GT40 Lunar Lander.
+respond "*" ":palx gt40;gtlem\r"
+expect ":KILL"
+
 # KL10 front end debugger.  Put it in the same directory as the
 # "MX" IOELEV.
 respond "*" ":palx sysbin;_syseng; klrug\r"
diff --git a/doc/programs.md b/doc/programs.md
index 8f8b9f2d..0b1583ad 100644
--- a/doc/programs.md
+++ b/doc/programs.md
@@ -89,6 +89,7 @@
 - GETSYM, copy all symbols from running ITS to a file.
 - GLP/XGP, queue files to be printed by GLPSPL/XGPSPL.
 - GLPDEV/XGPDEV, device for viewing GLPSPL/XGPSPL printer queues.
+- GTLEM, GT40 Lunar Lander.
 - GO, the Go board game.
 - GUESS, a very silly game.
 - GMSGS, copy system messages to mail file.
diff --git a/src/gt40/gtlem.mac b/src/gt40/gtlem.91
similarity index 99%
rename from src/gt40/gtlem.mac
rename to src/gt40/gtlem.91
index aff8d553..6d6ed256 100644
--- a/src/gt40/gtlem.mac
+++ b/src/gt40/gtlem.91
@@ -10,7 +10,20 @@
 ;			P.O. BOX 411
 ;			MAYNARD, MASS.
 ;					01754
+;
+;	GTLEM.91,	AUGUST 1, 2018
+;	UPDATED FOR PALX BY LARS BRINKHOFF
 ;*********************************************************************
+
+	R0=%0
+	R1=%1
+	R2=%2
+	R3=%3
+	R4=%4
+	R5=%5
+	SP=%6
+	PC=%7
+
 	IN1=R0				;INPUT REGISTER FOR SUBROUTINE CALLING.
 	IN2=R1				;SECOND VALUE.
 	RET1=R2				;HIGH ORDER PORTION OF SUBROUTINE RETURN.
@@ -111,6 +124,7 @@
 ;		ZERO DEGREES IS AT THE TOP, 90 TO THE RIGHT, ETC.
 ;			M A I N   D A T A   A R E A .
 ;
+	.=400
 TURN:	.WORD	0			;PRESENT RATE OF TURN AS SELECTED BY USER.
 ANGLE:	.WORD	0			;ANGLE CURRENTLY BEING USED FOR TRIG CALCULATIONS.
 ANGLER:	.WORD	0			;REMAINDER OF ANGLE FOR TURNING.