What do you mean ‘The binary is the source’?

Yesterday I mentioned a utility that we include in the Virtual Machine Additions for DOS – ‘IDLE.COM’.  When we came across to Microsoft (from Connectix) we found out that for various technical and legal reasons – Microsoft has strict policies about having source code available for all shipping products (you would be surprised to find out how many products are built with binary files for which the source code has long been lost).  Thankfully Connectix had done a good job of ensuring that the source code for all components of Virtual PC had been well maintained.

However – one day a tester raised the issue that he could not find the source code for IDLE.COM.  When he alerted Program Management and Development about this the Virtual PC Lead Developer – Aaron Giles (http://www.aarongiles.com/) – responded by smiling and saying ‘The binary is the source’.

Needless to say this resulted in a number of blank stares and furrowed brows – until Aaron explained that he hand-constructed IDLE.COM in assembly using DEBUG.  So he was completely justified in saying that the binary was the source.  Since this time we have added a second hand-constructed file – ‘VMADD386.SYS’ which was also built by Aaron.

And – on a slightly related note – it turns out that this is not the first instance of this at Microsoft.  The following Knowledge Base article on ‘REBOOT.COM’: http://support.microsoft.com/kb/q67929/ tells users how to ‘build their own REBOOT.COM’ using DEBUG.  Hmmm…  You have to think it would have been easier to just let people download the file 🙂