If you're communicating using DF1 or DH-485 protocol, then it should be RSLinx Enterprise that you're using, not RSLinx Classic. If you're setting up communications in FactoryTalk View Studio, then it is RSLinx Enterprise that you are using, and definitely not RSLinx Classic.
I don't know which model you're using, but the MicroLogix 1000 is available with 10, 16, or 32 discrete I/O, or with 20 discrete and 5 analog. So even if you're seeing one word each of I and O, it's far from a full compliment of I/O for a MicroLogix 1000. There should definitely be more I/O visible.
There was a data access anomaly with RSLinx Enterprise v5.21 and the MicroLogix 1000 Series A, where doing this very thing resulted in erroneous data.
What version of RSLinx Enterprise are you using?
What series is the controller?
You should also be able to read/write I/O Data File addresses directly from the MicroLogix 1000 and not need to map the addresses first.
When entering shortcut names for a PLC, SLC, or MicroLogix device, RSLinx Enterprise recognizes a slash "/" as a bit delimiter, but does not recognize a period "."
For example:
I:1/0 is acceptable
I:1.0 is not acceptable and generates an error.
Regards,
George