Simulator and 24 Bit instructions

[Frank Ch. Eigler]

Hi -

> I'm having now problems with 24 Bit instructions in the simulator.
> [...]
> So 24 Bit instructions are a problem. I hacked
>    case 24 : insn_value = (T2H_4 (insn_buf.words[0]) / 256) & 
>                            0x00ffffff; break;

It would be more transparent to explicitly fetch three bytes.  But why
is base_length 24 rather than 8?  It seems that you have come some way
since the posting of your .cpu file last week.  It may help to post
your current version.

- FChE