The problem
The AT&T 6300 was AT&Ts clone version of the Intel 8088 chip present in the first IBM personal computer. At that time “clones” were rare and unreliable.
The solution
To demonstrate the 6300´s compatibility Lon was contracted to create an automated example using Lotus 1-2-3 DOS version 1A. Lotus 1-2-3 was considered a benchmark for personal computer compatibility. Lon used the macro language feature in Lotus to automate the demonstration. AT&T used this Lotus macro in convincing the personal computer world that their 6300 would run all the same software that the IBM personal computer did.
Secrecy
Lon was under a top secret agreement during the project and was not able to reveal the existence of the AT&T personal computers to anyone. He recalls the floppy disks from Microsoft having various customized versions of MSDOS for AT&T to use in their eventual product branding.