I use a mac.With macports I have installed Hercules and c3270.Through this site: Running the IBM OS/360 MVT operating system on Hercules ,I followed the instructions and have downloaded the Hercules-ready MVT 21.8 images.
I tried a different setting.On mac os x I have installed Vagrant ,and a vagrantbox for linux 14.04lts. I downloaded from The MVS 3.8j Tur(n)key 4- System the zip-file tk4-_v1.00_current.zip. And I installed with sudo apt install c3270 the telnet terminal emulator in the linux vagrantbox.
Then I could fill in username and password.Obviously this is not solving how to use any version of IBM System/360 etc. directly on mac os x. The TK4 version didn't seem to work on os x and is probably preconfigured for Linux and not os x.However I am glad it does work the other way.
Apparently, this program not only supports decimal literals but also octal literals. In order to reach localhost (a loopback address back to the requesting computer on almost every modern system) you need to use the IP address 127.0.0.1, which is 0x7F000001 as a hexadecimal literal or 017700000001. So, try that number in place of 010.
c80f0f1006