Pretty sure that this constraint is related to cache-size and that your code 
can cross a page boundary.  Code of any length could potentially cross a page 
boundary so if that were an actual constraint it would be explicitly stated 
without associating it with a particular byte-length.

Keven

> On Jan 28, 2021, at 21:06, John Dravnieks <[email protected]> wrote:
> 
> Hello
> 
> Constrained transactions have some constraints detailed in Chapter 5 of POP - 
> the one I am curious about is this one:
> 
> All instructions in the transaction must be within 256  contiguous  bytes  of 
>  storage,  including  the
> TRANSACTION  BEGIN  (TBEGINC)  and  any TRANSACTION END instructions.
> (Number 2 on page 5-107 in Principles of Operation  SA22-7832-12)
> 
> My question is does this mean that the TBEGINC and TEND instructions must be 
> in the same page or not?
> for example, would this code operate correctly with the TBEGINC and TEND in 
> different pages ?
> 
> 
> 000FF8 E561 0000 0000 00000           5          tbeginc 0,0
> 000FFE 0610                           6          bctr  1,0
> 001000 5010 D000            00000     7          st    1,0(,13)
> 001004 B2F8 0000                      8          TEND
> 
> Kind Regards
> John Dravnieks, 21st Century Software

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