Category: Windows

Free Windows 10 VM

Free Windows 10 VM

Windows running in Hyper-VYou can get a special developer enabled VM of Windows 10 for VMWareHyper-VVirtualBox, and Parallels. This VM has a time limited version, expiring in April 2021 of Windows 10 (2004 version), and includes Visual Studio with the UWP, .NET desktop, and Azure workflows enabled and also includes the Windows Template Studio extension, Visual Studio Code, plus Windows Subsystem for Linux enabled with Ubuntu installed and Developer mode enabled.

It’s a 20 GB download that you can get here. The screenshot is Window 10 (fully licensed!) running under Hyper-V. I keep some old development software on it that’s a real pain to reinstall. I just have to keep it backed up and can easily copy it to my next PC. Much less hassle!


An example of what you can do with MonoGame

An example of what you can do with MonoGame

OpenVIII screenshotMonoGame is not just for mobile, as I’ve been doing. Open VIII is a Final Fantasy VIII game engine written in C#/MonoGame and currently works on Windows and Linux (not sure about Mac). Other games in the series have been ported to other platforms but not FFVIII, so that’s why the project was started.

The instructions for Open VIII on Windows suggest Visual Studio 2017 but I imagine 2019 might also work as MonoGame 3.8 has templates for it.  As the project says “OpenVIII is an open-source complete Final Fantasy VIII game engine rewrite from scratch powered in OpenGL making it possible to play the vanilla game on wide variety of platforms including Windows 32/64 bitLinux 32/64 bit and even mobile!

As with virtually all open source reimplementations, you will have to provide your own game assets such as images and sound. You can do this apparently by buying the original game on Steam. I took a look and sure enough it’s there and there’s an official remastering by Square Enix. I’m not sure why the Steam search brings up FF VII as well but hey that’s search for you… I’ve added a permanent link to the C#/MonoGame links page.

Steam Final Fantasy VIII

How to install WSL 2 and Linux on Windows 10

How to install WSL 2 and Linux on Windows 10

Winver commandThis assumes that you have the version 2004 of Windows 10. Run the command Winver (open a command line then type winver) to see what version you have.

WSL is Windows Subsystem for Linux and lets you run one of several Linuxes (after installing) in Windows. For now it is terminal only but you can debug programs using Visual Studio. WSL 2 is the current version of WSL though you can run the older WSL 1.

Your computer also needs to support Hyper-V Virtualization to run WSL 2. If it doesn’t you can run WSL 1.


  1. Open a PowerShell windows in Admin mode. My way of doing this is open the search window and type Powershell. Then right-click run as Admin.


When I mean Search Window, I mean the one on the Toolbar that looks like this like a magnifying glass: (highlighted in the red square)

Search Window



2. In the Powershell Windows, copy and paste this command:

dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart

3. Next run this command in the same Windows:

dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart

4. Set WSL 2 as default with this Powershell command:

wsl --set-default-version 2

Now close the Powershell Window and in the search box type Store. You should see Microsoft Store.  It’s an app on your PC. Click it to run it and type in Linux in the search box. Click Show all and you should see something like this. Pick one like Ubuntu, Debian etc.  Apart from the ones with a price against them, the rest are free. Cl;ick Get and it will install.

Linux in Microsoft Store

After it has installed, you can run it from your Start Menu. I dragged it onto the square so I have a nice clickable icon.

Windows Start MenuJust click it and your Ubuntu (or whatever) Linux will open at a terminal prompt like this.

Ubuntu Terminal


How to install SDL2 in Visual Studio

How to install SDL2 in Visual Studio

Visual Studio IDEThis is the first of a number of longer-piece game related tutorials. You’ll see I’ve added a tutorials link to the top menu. That page will grow as I add tutorials, as each is added to it .

You’ll see I use the terms SDL and SDL2 mostly interchangeably. SDL is the name of the library but we don’t want the older SDL1 instead we want SDL2 which seems more or less permanently at version 2.0.12.

I’ve left the Visual Studio version off as the process is mostly the same whether it’s Visual Studio 2017, 2019 or future versions. Screenshots are from Visual Studio 2019.

You don’t have to do this on Linux as it takes three or four sudo apt installs to add the various SDL2 dev modules in, but with Windows you need to configure Visual Studio and it can be a somewhat confusing process if you are new to Visual Studio.

Also you need to download and fetch the various files. This is made slightly more complicated because there are 32-bit and 64-bit versions and you want to keep them both so you can switch between the two.

Here are the various steps we have to go through.

  1. Download the various files and unzip them
  2. Setup include and lib paths in Visual Studio
  3. Add the lib files into Visual Studio.
  4. Copy the dlls into the folder where the game will run.
  5. Compile and run it.

What you are downloading are basically three types of files.

  1. Header files., This is files like sdl.h.  Your program will #include these.
  2. Lib files. This is the bulk of the SDL code.
  3. Dll files (Dynamic Link Liobraries). Needed for runtime.

Download the various files and unzip them

The SDL website is and if you click the SDL Releases in the bottom right it will take you to the SDL downloads page. WE don’t need the source code (you are welcome to download it and take a look but it’s not needed to use SDL2.

We do however need the development libraries. These include the runtime binaries so we don’t need to download those. as well. Just the one file

I suggest you create a folder SDL or SDL2 on your drive. My C: drive is for Windows so I use d: \SDL2

If you unzip the files into there you’ll end up with three folders and five .txt files. Just under 7 MB in total. Other than docs there are include and lib.  The lib folder is further split into x64 (64-bit) and x86 (32-bit) . It also includes the runtime dlls. These will have to be in the path for your program but we’ll leave that until later.

Sounds, Images and Truetype fonts

As well as these, you are probably going to want image file support, sounds and possibly truetype font support in your program. These are separate files in the SDL projects folder.

  1. Image file support. Download the development library file from the sdl_image page. As before you want development library file.
  2. Sounds file support. Download the development library from the sdl mixer page. It’s
  3. ttf file support. Once again a development library downloaded from the SDL_ttf project page. It’s

All three files have similar structure to the SDL2 dev library.  Unzip the include files into the SDL include folder and the lib files into the relevant X86 and X64 lib sub-folders. So all your SDL files that you need are in the same include and lib sub-folders.

I suggest you extract the file folders one by one, do the three include files first then the x64 files and then the x86. Do not get x86 and x64 mixed up. The only way to tell them apart is by size and it’s not always an accurate way.  Don’t worry if it complains about overwriting zlib1.dll. There’s a copy in both the images and sounds zip files.

Setup include and lib paths in Visual Studio

This can be a bit complicated, just follow these instructions exactly.

To configure a C/C++ project in Visual Studio, you have to specify where the compiler gets its include files, where it finds its lib files and which lib files you want to link to.

Solution ExplorerI’ve created a blank C++ project called sdltest in VS 2019.  Now I actually want it to be a C project so just rename the main file sdltest.cpp to sdltest.c. You need to delete all of the C++ code in that file as well.  After renaming the Solution Explorer should look something like this. We will have a sdltest program to run later so just save this for now. You can get the file from GitHub and overwrite sdltest.c.

Now click Project on the top menu then sdltest properties at the foot of the menu.  You should see this form (below).  This is how you specify properties for your project in Visual Studio.

You’ll see I have selected VC++ Directories on the left. This is where you specify some of the directories (folders and directories mean the same thing BTW) .

But the Platforms pull down probably shows Win32 on yours. Change it to All Platforms. Visual Studio lets you specify configurations for all things or for x86 or x64 separately. We’ll use the same include folders for both x86 and x64 but we’ll specify the paths to the lib files individually as the x64 lib files are in the x64 sub-folder and the x86 files in the x86 folder.

Property Pages
To specify the path click on Include Directories, you’ll see a down arrow appear on the right.  Click it and you’ll see <Edit…> appear, click it and a form like this below will popup.
Visual studio folder editClick on the blue area in the form and you’ll be able to paste or type in the path or click the … button to get a file browser appear. Type in, paste or select the folder then press Ok.  You should now see your path in the folders.

Here I typed in d:\SDL\Include. Be careful that you don’t get rid of $(VC_includePath);$(WindowsSDK_IncludePath); in the include path as I did as your program won’t compile!

folder paths

We now have to do the same for the lib paths.  But first we must change the Platform to specify x86 or x64.

If you change it, a popup will appear asking if you want to save your changes. Click the Yes button.

Confusingly the platform choices on mine are Win32 and x64, but Win32 is the same as x86.

You’ll see that the include path you added shows up in the x86/Win32 platforms because we changed it for all platforms.

Now add the path for Library Directories. Click the down arrow then <edit…> and put in the full path to the folder that matches the Platform. x86 for Win32 platform, x64 for x64 platform. After you’ve entered it will show up in the directories.

Visual studio all paths

If you want both x64 and x86 then change the platform and re-enter it. Don’t forget to save!

Add the lib files into Visual Studio

The last configuration to do is specify the lib files that are needed. We’ve specified the paths for include and lib files but the compiler linker doesn’t know what lib files to link.

As linking depends on 32-bit or 64-bit we have to specify this twice as we did for the lib paths. It’s in a different place in the property pages. Click Linker then Input.

Visual Studio Linker Configuration It’s the top line (Additional Dependencies) that we need to work with. Click into it to get the down arrow then click that and the <edit…> as before.

You’ll have noticed that it comes pre-populated with all the various library .lib files.  We’ll be adding some more. The ones we need are

SDl2.lib SDL2_mixer.lib SDL2_ttf.lib SDL2_image.lib and SDL2main.lib

Add these into the edit box one by one and press return after each one.

After you’ve added them and pressed Ok, you’ll see them in a list. Something like this though I’ve not added SDL2_ttf.lib in to it yet.

As before repeat for both x86 and x64.


We’re now ready to compile. Only we need a program to do that. I’m not going to list the whole sdltest as it’s 135 lines but you can download the VS project in the file from GitHub. It should compile with no errors. If you get errors, please recheck the include folders and lib folders and make sure you have configured them correctly.

So it compiles, but it won’t run. If you look in the Debug folder under the x64 (or Win32 if you built that) , you’ll see a whole lot of files. but only sdltest.exe is important. You can delete the rest. Leave sdltest.pdb if you wish to debug.

We have to

Copy the dlls into the folder where the game will run

That folder is this the \sdltest\x64\Debug folder. We need several .dll files from the same lib folder that holds the x64 libs. (Again if you are on Win32 you need dlls from the x86 lib folder).

What files do we need?

Just SDL2.dll. If we were using images we’d also need sdl2_image.dll and zlib1.dll. We don’t currently need the SDL2_mixer.dll or the SDL2_ttf.dll but if you ever use sounds or Truetype then you’ll need those. For sounds you’ll also need some of the lib*.dll files such as libogg-0.dll or libvorbis-0.dll. For image we might need in the future libjpeg-9.dll (if we ever use jpg files).

So you’ve compiled it and should see something like this when you run sdltest.exe. It doesn’t do much except draw coloured rectangles. Press the esc key to close it. On my POC it draws 100,000 coloured rectangles each 120 x 120 pixels in about a second. That’s pretty fast!

The heart of the program is this function:

void DrawRandomRectangle() {
	char buff[20];
	SDL_Rect rect;
	SDL_SetRenderDrawColor(renderer, Random(256) - 1, Random(256) - 1, Random(256) - 1, 255);
	rect.h = 120;// Random(100) + 20;
	rect.w = 120;// Random(100) + 20;
	rect.y = Random(HEIGHT - rect.h - 1);
	rect.x = Random(WIDTH - rect.w - 1);
	SDL_RenderFillRect(renderer, &rect);

	if (rectCount % 100000 == 0) {
		sprintf_s(buff, sizeof(buff), "%10.6f", getElapsedTime(&s));

Uncomment the two lines with 120; // Random(100) + 20; to have it draw random sized rectangles. The figure in the caption is how long it takes to draw 100,000 rectangles.

My encryption code is now live on GitHub

My encryption code is now live on GitHub

Crptography Word list
Image by tumbledore from Pixabay

I developed Pivot initially on Windows, (a Linux version will follow) though the differences are fairly small. I used the Windows _sopen_s for reading and writing files.  There shouldn’t be too much differen otherwise, though I guess I’ll find out when I compile it on Ubuntu or Raspberry Pi.

The program itself is around 450 lines of C in just one file. It can encrypt around 6 MB/s on my five year old i7 5930K PC and decrypt at around 10 MB/s.

If anyone could try this, I’d be very happy. It has one minor issue that I will resolve. Because it processes files in blocks of 64 bytes, it tends to round the output file when decrypting and adds a few 0s on the end. I will get it sorted

I’ve given it a very liberal MIT license, you can do what you want with it. Instructions on using it are provided on that link to GitHub.

This BTW is the encryption code at the heart of it.

        int bit = 128;
        for (int bi = 0; bi < 8; bi++) {
            for (int b = 0; b < NUMSTREAMS; b++) {
                dataout[b] = (dataout[b] >> 1) | (data[b] & bit);
                data[b] <<= 1;
        // Now alter the order of bytes according to the key
        for (int i = 0; i < NUMSTREAMS; i++) {
           data[i] = dataout[_key[i]];

The first double for loop slices 64 bytes into 64 bit streams. It’s pivoting the bits if you like, hence the name. The second for loop is what does the donkey work of encrypting it. It uses a 64 byte key (made up of 64 numbers 0-63- shuffled). As there are 1.2688693e+89 different ways of arranging these 64 numbers, if you lose the key it might take you a while to brute force it!

So I believe that it is an original encryption algorithm, but I am not an expert in cryptography so I might be making a fool of myself! Whether there are any possible attacks against it, I don’t know, but it will be interesting to see!

Visual Studio Vs Visual Studio Code?

Visual Studio Vs Visual Studio Code?

I wrote the first book on Windows and used Visual Studio Community Edition 2017 (VS). For Linux I’m using Visual Studio Code (VSC) but if you are working on Windows you have the choice. So which is better suited to you?

Disassembly of OutputDebugString program

Given that my full time job involved Visual Studio Professional, it wasn’t a difficult choice for me, though having used VSC on Linux, I’m now warming to it.

I found the configuration messy but if you stick at it, you get there. It’s a fairly simple product but once you get into all the configuration and extensions, there’s a lot more to it.

VS (now at 2019 version) is an excellent tool and the navigation features and debugging are better than VSC. You can also view disassembly of C code as the screenshot shows.

But if you are also working on Linux or Mac and using VSC, it might be easier or at least more consistent using it for all platforms. Mind you there’s also the question of MSVC vs Clang to sort as well.

VS has extensions but only 3271 currently compared to 16934 for VSC and many of the VS extensions are trial while it appears that all of VSC are free. There’s also nearly ten times as many programming language extensions for VSC (3427) compared to VS (351).

So there’s no outright clear winner here. YMMV as the saying goes. (Your mileage may vary). Here for your delectation is that disassembly including the original C lines. Don’t worry, I won’t publish too many of these!

int main()
00E31700  push        ebp  
00E31701  mov         ebp,esp  
00E31703  sub         esp,0CCh  
00E31709  push        ebx  
00E3170A  push        esi  
00E3170B  push        edi  
00E3170C  lea         edi,[ebp-0CCh]  
00E31712  mov         ecx,33h  
00E31717  mov         eax,0CCCCCCCCh  
00E3171C  rep stos    dword ptr es:[edi]  
00E3171E  mov         ecx,offset _1EF31893_ods@c (0E3C00Ch)  
00E31723  call        @__CheckForDebuggerJustMyCode@4 (0E3120Dh)  
    wchar_t * text=L"Hello World!\n";
00E31728  mov         dword ptr [text],offset string L"Hello World!\n" (0E37B30h)  
00E3172F  mov         esi,esp  
00E31731  mov         eax,dword ptr [text]  
00E31734  push        eax  
00E31735  call        dword ptr [__imp__OutputDebugStringW@4 (0E3B000h)]  
00E3173B  cmp         esi,esp  
00E3173D  call        __RTC_CheckEsp (0E31217h)  
00E31742  xor         eax,eax  
00E31744  pop         edi  
00E31745  pop         esi  
00E31746  pop         ebx  
00E31747  add         esp,0CCh  
00E3174D  cmp         ebp,esp  
00E3174F  call        __RTC_CheckEsp (0E31217h)  
00E31754  mov         esp,ebp  
00E31756  pop         ebp  
00E31757  ret  
Logging on Windows – OutputDebugString

Logging on Windows – OutputDebugString

Shows OutputDebugString being calld in the debuggerIn the post about rsyslog three days ago, I explained how to log from Linux programs using the rsyslog daemon.

It’s slightly different in Windows. There’s a built in function called OutputDebugString(LPCWSTR str) that you can call from anywhere in your program. It dumps the string str into the Output window if you are debugging it in Visual Studio.

If you are running this outside of a debugger, the output is lost unless you can capture it with a suitable utility. DebugView from (it redirects to Microsoft) is one such utility. That’s a screenshot of it below.

Showing DebugView in actionJust run DebugView and leave it there. It might catch other stuff from Windows, but when you run your program from the command line or double click on it, it will execute quickly and you’ll see any strings captured like this one.


This is the program that I ran. In Release it compiles to a 9 KB exe! Because OutPutDebugString needs a LPCWSTR  (Long Pointer to a WideString), I declared the text as wchar_t.

#include <Windows.h>

int main()
    wchar_t * text=L"Hello World!\n";

At work I developed a very large program that only worked running on another computer. I used OutputDebugString extensively and without it, debugging would have been much harder.