Gates and Allen had neither an interpreter nor even an Altair system on which to develop and test one. However, Allen had written an Intel 8008 emulator for their previous venture Traf-O-Data that ran on a PDP-10 time-sharing computer. He adapted this emulator based on the Altair programmer guide, and they developed and tested the interpreter on Harvard's PDP-10. Harvard officials were not pleased when they found out, but there was no written policy that covered the use of this computer.[8] Gates and Allen bought computer time from a timesharing service in Boston to complete their BASIC program debugging.