From 3588ff716144a3a228cff65c9ac2feb84e79a8fc Mon Sep 17 00:00:00 2001
From: Memotech Bill <64212746+Memotech-Bill@users.noreply.github.com>
Date: Thu, 25 Apr 2024 11:59:22 +0100
Subject: [PATCH] Documentation and error checking improvements

---
 CMakeLists.txt  | 6 +++++-
 docs/index.html | 5 ++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a5b370b..69410e7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -290,7 +290,9 @@ elseif("${TARGET}" STREQUAL "Circle")
   set(CMAKE_CXX_LINK_EXECUTABLE
     "<CMAKE_LINKER> -o <TARGET> <LINK_FLAGS> <OBJECTS> --start-group <LINK_LIBRARIES> --end-group")
 
-  if (${RPI} EQUAL 1)
+  if (NOT DEFINED RPI)
+    message(FATAL_ERROR "No Raspberry Pi version specified, use -DRPI=...")
+  elseif (${RPI} EQUAL 1)
     set(ARCH -DAARCH=32 -mcpu=arm1176jzf-s -marm -mfpu=vfp -mfloat-abi=hard)
     add_compile_definitions(RASPPI=1)
     set(KERNEL kernel.img)
@@ -306,6 +308,8 @@ elseif("${TARGET}" STREQUAL "Circle")
     set(ARCH -DAARCH=32 -mcpu=cortex-a72 -marm -mfpu=neon-fp-armv8 -mfloat-abi=hard)
     add_compile_definitions(RASPPI=4)
     set(KERNEL kernel7l.img)
+  else()
+    message(FATAL_ERROR "Invalid Raspberry Pi version")
   endif()
 
   add_compile_definitions(__circle__)
diff --git a/docs/index.html b/docs/index.html
index 26b47b7..2c28e86 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -254,7 +254,7 @@ <h3 id="Build-Circle">Bare-Metal Raspberry Pi Build</h3>
         cd MEMU
         mkdir build-circle
         cd build-circle
-        cmake -DTARGET=Circle -DRPi=? ..
+        cmake -DTARGET=Circle -DRPI=? ..
         make
     </code></pre>
     <p>If required it is possible to create multiple build folders (e.g. "build-circle1"
@@ -305,6 +305,9 @@ <h3 id="Usage-Basic">Basic Usage</h3>
     <p>For instructions on using MEMU as a Memotech, please read the Memotech manuals, copies
       of which can be found <a href="http://primrosebank.net/computers/mtx/mtxmanuals.htm">
         here</a>.</p>
+    <p>For versions of MEMU (FBuf, RPi, Circle)  which use the full screen to display each MTX
+      screen (VDP, CP/M ...) use keys &lt;Ctrl+F1&gt;, &lt;Ctrl+F2&gt; etc. to switch between
+      each screen.</p>
     <p>To configure MEMU for different emulation modes, open the configuration screen or window.
       Because different operating environments capture different keys, a number of different key
       presses may be used to open this screen:</p>