On 31 August 2010 11:23, John P. Baker <[email protected]> wrote:
> The original IBM 360 had 142 (documented) instructions, of which 11 were > privileged. > > All of the original non-privileged instructions remain available. > > Of the privileged instructions, 5 remain available. The 6 that have been > dropped consist of 4 comprising the S/360 I/O feature and of 2 comprising > the S/360 Direct Control feature. I think a few more than 6 of the old privops have gone. SSK/ISK and RRB come to mind, and there are more than 4 I/O instructions that have disappeared, even if you count pairs like HIO/HDV and SIO/SIOF as just one each. Tony H.
