If this is your first time, please wait for the framework to load. Currently no Ctrl-keys will be sent to the emulator from the browser. Therefore, use the buttons under the terminal window.
Use of floppy disks: Under File, select the Catalog to import a disk into your browser's cache. Then mount it under Devices. If you need an empty disk, then import TOM180.dsk. Then before you import, you can rename the disk to another name.