From e41912b07644864a3a685ac339de2085d252706e Mon Sep 17 00:00:00 2001
From: nickysn <nickysn@gmail.com>
Date: Mon, 22 Jun 2020 14:13:54 +0000
Subject: [PATCH] * limit the ZX Spectrum programs address space up to $FDFC,
 because the RTL now   installs an interrupt handler at $FDFD

git-svn-id: trunk@45678 -
---
 compiler/ogrel.pas                | 20 ++++++++++++++++++++
 compiler/systems/t_zxspectrum.pas |  2 +-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/compiler/ogrel.pas b/compiler/ogrel.pas
index bc527f8104..fce7d07cf4 100644
--- a/compiler/ogrel.pas
+++ b/compiler/ogrel.pas
@@ -131,6 +131,13 @@ interface
         constructor create;override;
       end;
 
+      { TZXSpectrumIntelHexExeOutput }
+
+      TZXSpectrumIntelHexExeOutput = class(TIntelHexExeOutput)
+      public
+        constructor create;override;
+      end;
+
 implementation
 
     uses
@@ -1321,6 +1328,19 @@ implementation
         MaxMemPos:=$FFFF;
       end;
 
+{*****************************************************************************
+                         TZXSpectrumIntelHexExeOutput
+*****************************************************************************}
+
+    constructor TZXSpectrumIntelHexExeOutput.create;
+      begin
+        inherited create;
+        { The ZX Spectrum RTL switches to interrupt mode 2, and install an
+          interrupt handler + table, starting at address $FDFD, so we must limit
+          program size to $FDFC }
+        MaxMemPos:=$FDFC;
+      end;
+
 {*****************************************************************************
                                   Initialize
 *****************************************************************************}
diff --git a/compiler/systems/t_zxspectrum.pas b/compiler/systems/t_zxspectrum.pas
index 2bdb1484f5..6dfe48d3da 100644
--- a/compiler/systems/t_zxspectrum.pas
+++ b/compiler/systems/t_zxspectrum.pas
@@ -392,7 +392,7 @@ constructor TInternalLinkerZXSpectrum.create;
   begin
     inherited create;
     CArObjectReader:=TArObjectReader;
-    CExeOutput:=TIntelHexExeOutput;
+    CExeOutput:=TZXSpectrumIntelHexExeOutput;
     CObjInput:=TRelObjInput;
     if ImageBaseSetExplicity then
       FOrigin:=ImageBase