
New Tricks for an Old Z-Machine, Part 1: Digging the Trenches - pmoriarty
https://www.filfre.net/2019/10/new-tricks-for-an-old-z-machine-part-1-digging-the-trenches/
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dwheeler
> So, even if highfalutin phrases like “virtual machine” weren’t yet tripping
> off the tongue of the average bedroom hacker, it wasn’t hard to divine what
> Infocom must be doing in the broad strokes. The specifics, however, were
> another matter. For, while Infocom didn’t hide the existence of a Z-Machine
> in the abstract, they had no vested interest in advertising how it worked.
> ... But plumbing the depths of a virtual machine whose very existence was
> only implicit was hard work

This is extremely misleading. Sure, some of the depths weren't published, but
Infocom published how the Z-machine worked in a variety of forums. Most
accessible is "How to fit a large program into a small machine" by Marc S.
Blank and S. W. Galley, published in Creative Computing, 1980. Creative
Computing was widely read at the time. It explained how integers and strings
were stored as well as the general approach. Blank was one of the key
developers of Zork. You can view the paper here:
[https://mud.co.uk/richard/htflpism.htm](https://mud.co.uk/richard/htflpism.htm)

Of course, it took some effort to work out the exact opcodes, but there was a
_lot_ of publicly-available information to start from.

~~~
dwheeler
In addition to Creative Computing, 1980: "How to Fit a Large Program Into a
Small Machine" by Blank/Galley

There were at least two other articles published at the time that provided a
lot of details:

* IEEE Computer, 1979: "Zork: A Computerized Fantasy Simulation Game" by Lebling/Blank/Anderson

* Byte, 1980: "Zork and the Future of Computerized Fantasy Simulations" by Lebling

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thomasjudge
Part ii: [https://www.filfre.net/2019/11/new-tricks-for-an-old-z-
machi...](https://www.filfre.net/2019/11/new-tricks-for-an-old-z-machine-
part-2-hacking-deeper-or-follies-of-graham-nelsons-youth/)

Part iii: [https://www.filfre.net/2019/11/new-tricks-for-an-old-z-
machi...](https://www.filfre.net/2019/11/new-tricks-for-an-old-z-machine-
part-3-a-renaissance-is-nigh/)

