I have a C++ source code of the game for Android. I want to port it to a Windows Phone. I hope it mean only change an API for platform-specific calls. The problem is that I cannot use SDK 8 Emulator because I have to old CPU (and I cannot buy a new computer now). Moreover, I cannot use SDK 7.1 Emulator because the source code is native C++.
Questions:
Can I choose WP 7.5 as a target platform in SDK 8 and then test XAP file on Emulator 7.1?
Can I port application without any Emulator and at final stage test it on the other computer with SDK 8 Emulator?
Instead the emulator I can test it directly on the phone, am I right?
Any other ideas that I missed?
First of all, I seriously doubt you can port your Android C++ program directly into Windows Phone with only little changes because all platforms are completely different.
Of course you can use C/C++ libraries in Windows Phone 8, but only those created to be uses in Windows, not Linux (that is Android), and you need to port them even if they are Windows one.
Here are the only Win32 API that are compatible with Windows Phone 8: http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj662956(v=vs.105).aspx
In relation to your questions, Windows Phone 8 SDK contains Windows Pone 7.5 emulators and can create Windows Pone 7 projects. Of course, Windows Phone 8 emulators can execute Windows Phone 7 applications without trouble.
You can debug directly in a Phone, but you need a Developer Account (99 bucks) and "activate" the phone with Windows Phone Registration Tool that is in SDK.
However, you cannot use C/C++ in Windows Phone 7. Your base project version must be WP8, and only compatible Win32 calls.