[z-machine] Small contribution to the ZMachine specs

[Ben Collins-Sussman]

On 3/26/06, Johnny Billquist <bqt at update.uu.se> wrote:

> Anyway, the Z-Machine spec is really more complete than given credit for
> here. This specific question is dealt with in chapter 10.
>

Ah!  Thank you!


> It's a grave mistake to try to write an interpreter from only reading
> the spec of the opcodes.
>

Actually, we've been doing nearly the opposite.  We've read almost the
entire spec... everything *but*  the opcodes.  We've been writing all
sorts of subsystems (memory, zscii routines, op decoder, stack
management, object parsing, dictionary parsing), with the thought that
the opcodes would be implemented at the very end.

The only parts of the spec we haven't read yet are the I/O streams and
the opcodes.  Apologies!