[Simh] H316 LDX

[Bob Supnik]

What version of SimH are you using? You can safely revert to 3.8-0. (http://simh.trailing-edge.com/sources/simhv38-0.zip)

The problem is a cut-and-paste error introduced in 3.8-1 when the source was cleaned up to match more current C styling conventions.  Specifically, in 3.8-0:

    case 015: case 055:                                 /* STX */
        if (reason = Ea (MB & ~IDX, &Y)) break;         /* eff addr */
        Write (Y, XR);                                  /* store XR */
        break;

    case 035: case 075:                                 /* LDX */
        if (reason = Ea (MB & ~IDX, &Y)) break;         /* eff addr */
        XR = Read (Y);                                  /* load XR */
        break;


The "& ~IDX" term was omitted in 3.8-1, causing the bug you see.

You can either get the 3.8-0 sources from the web site, or interpolate these lines into your existing source.

This will be fixed in 3.8-2, if I can ever find the time to get it out the door.

/Bob