Everybody has a senior moment every now and then after 55, including me.

Joe

On Sat, Oct 23, 2021 at 7:44 PM Seymour J Metz <[email protected]> wrote:

> The D value is the offset of the literal from the relevant USING. the R
> values is the register from the USING and the X value is zero. This is very
> basic stuff.
>
>
> --
> Shmuel (Seymour J.) Metz
> http://mason.gmu.edu/~smetz3
>
>
> ________________________________________
> From: IBM Mainframe Discussion List <[email protected]> on behalf
> of Joe Monk <[email protected]>
> Sent: Saturday, October 23, 2021 8:18 PM
> To: [email protected]
> Subject: Re: Question about negative indexes
>
> OK then explain this:
>
> LH is an RX format instruction. What are the D, X and B values if the
> second operand is simply =H'-5'?
>
> Joe
>
> On Sat, Oct 23, 2021 at 6:49 PM Paul Gilmartin <
> [email protected]> wrote:
>
> > On Sat, 23 Oct 2021 18:36:54 -0500, Joe Monk wrote:
> >
> > >LH is an RX instruction.
> > >
> > >So, LH 3,=H'-5' would give an addressing exception, no? Because the
> second
> > >operand is treated as coming from storage? So that would be a negative
> > >address?
> > >
> > No.
> >
> > >If you said LH 3,0(=H'-5',2), that would give you ITEM+5?
> > >
> > You have a bad use-versus-mention conflation.  The value of an
> > object is not the address of that object.
> > <
> https://secure-web.cisco.com/1Cc9X8nq783UC9J1JPtocjSP8oRNQtIjc0McoHQ7Dtf7hx47AuzGkTpG-MLS99sZ2RSeM7alOdb0fbxcnvPz9zzu5iw78nnOQugSG7Tm2wQoCt-9eq5LOH7gGHvFOMpqRiViExjFhgouWtXfbCXTA4gu3IkungoCFH75HGqCCjnec1oxWUWhGKkF2mDRQg_Mms53pAP_MxCJQjMoaawvOnxiz7qylbKGzn6PIcwHGVLERZt_z-3Q0NiRU--NkN-xN8WVn_PcJHhTiOkpWb3-jM9a-5JIY6Gr3TYiitQoi0gkKgYHDMSQlhbEmkvHC1CJiIu9ZarjELQqRPXuNMnnD6zUOtjEILP1vZMMzsZtjiKmONurOOAZbk5ds0kBocuSiUnVfRbrRqny4U3OSwLU6ud4BNlijUY0_j-XIdiqqZsqCUDUKwYGmV5zLFby1SY0E/https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FUse%25E2%2580%2593mention_distinction
> >
> >
> >
> > >On Sat, Oct 23, 2021 at 6:01 PM Bernd Oppolzer wrote:
> > >>
> > >> LA   2,ITEM+10
> > >> LH   3,=H'-5'
> > >> LA   2,0(2,3)
> > >>
> > >> will put the address ITEM+5 in register 2, at least in AMODE 24/31?
> > >>
> > I agree.
> >
> > -- gil
> >
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> >
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