[Info-vax] Y3K for PDP-11 Operating Systems

[Bob Koehler]

In article <iqbllp$u0i$1 at Iltempo.Update.UU.SE>, Johnny Billquist <bqt at softjar.se> writes:
> 
> I'm pretty sure that on later machines, MOVTUC is an emulated 
> instruction, so you don't want to use it unless you really want the 
> special features. For the simple C string case, having that translation 
> table is a small memory cost, but it also hurts performance.
> But from a purity point of view, yes, MOVTUC should also be able to do it.

   IIRC, LOCC and MOVCx are in the same VAX instruction subset as
   MOVTUC.  And the rules were you can do all of a subset in hardware,
   or none of the subset in hardware, but you couldn't break it up.

   For example, IIRC, MV II did none of the string instructions in 
   hardware.