[purplesyringa]

So if it's not a bug in the emulator, then it's a bug in COMMAND.COM? I don't think that's the case, surely it couldn't have been missed by Microsoft at the time. The article goes on to talk about fread/fwrite calls, but COMMAND.COM was written in assembly, I'm pretty sure it didn't link to any libc, and certainly not to Open Watcom -- why would MS use it instead of their own library?

[grodriguez100]

It is not a bug. The article explains that this is the expected behaviour.

[purplesyringa]

What is expected behavior? Surely `echo AB> foo.txt; echo CD>> foo.txt` producing `ABBC` is either a bug in COMMAND.COM, the emulator, or something else? That can't be correct.