Editing ARM architecture family (section)

===ARM1===
[[File:Acorn-ARM-Evaluation-System.jpg|thumb|right|upright=1.4|ARM1 2nd processor for the BBC&nbsp;Micro]]
Acorn chose [[VLSI Technology]] as the "silicon partner", as they were a source of ROMs and custom chips for Acorn. Acorn provided the design and VLSI provided the layout and production. The first samples of ARM silicon worked properly when first received and tested on 26 April 1985.<ref name="ARM1"/> Known as ARM1, these versions ran at 6&nbsp;MHz.{{sfn|Evans|2019|loc=20:30}}

The first ARM application was as a second processor for the BBC Micro, where it helped in developing simulation software to finish development of the support chips (VIDC, IOC, MEMC), and sped up the [[CAD software]] used in ARM2 development. Wilson subsequently rewrote [[BBC BASIC]] in ARM [[assembly language]]. The in-depth knowledge gained from designing the instruction set enabled the code to be very dense, making ARM BBC BASIC an extremely good test for any ARM emulator.