Guys and gals, I wrote a simple called Assembler routine using TAM ...great works like a champ..Ty much appreciated
Scott ford www.identityforge.com from my IPAD 'Infinite wisdom through infinite means' On Jun 11, 2013, at 4:24 PM, John McKown <[email protected]> wrote: > OK, but I could argument that a specification exception definitely causes a > nasty "branch" to occur. <grin/> > > On Tue, Jun 11, 2013 at 1:39 PM, Tom Marchant <[email protected]>wrote: > >> On Tue, 11 Jun 2013 10:51:07 -0500, John McKown wrote: >> >>> Also, there is the SAM instruction to change AMODE as needed without >>> branching (well except for the horrible case where you are RMODE(31) and >>> switch to AMODE(24) causing a really nasty "branch" to occur). >> >> Nope. That causes a specification exception. >> >> <quote from the POO> >> The instruction is completed only if the new >> addressing mode and the unupdated instruction >> address in the PSW are a valid combination. When >> the new addressing mode is to be the 24-bit mode, >> bits 64-103 of the unupdated PSW must be all >> zeros, or, when the new addressing mode is to be >> the 31-bit mode, bits 64-96 of the unupdated PSW >> must be all zeros; otherwise, a specification >> exception is recognized. >> </quote> >> >> -- >> Tom Marchant > > > > -- > This is a test of the Emergency Broadcast System. If this had been an > actual emergency, do you really think we'd stick around to tell you? > > Maranatha! <>< > John McKown
