It use the MSComm control to comunicate with your MSR 605. This code should work also for the MSR206 Because i've used the MSR206 Programmer's Manual to understand how to communicate with the device.

MagTool provides a simple, intuitive interface to MSR206-compatible devices. The software features read, write, duplicate, and erase support for MSR206-compatible readers and writers (including MSRW ...