I’ve established that the Infocom Z machine interpreter I have for CP/M is limited to version 3 story files and have therefore spent the last day or so trying to decide which course would be best to take for development of the game.  I’ve opted for Inform version 5.5 for DOS which I downloaded at the excellent ifarchive.  This is one of the last versions of Inform that will compile version 3 story files.  I was advised by DavidK over at the interactive fiction forum that Inform 6.15 is actually the last version that supports version 3.

He was also kind enough to point me in the direction of Dave Bernazzani’s minform library which is a stripped down Inform Library created to allow small z3 files.  Using the Inform Designers Manual by Graham Nelson I created a few rooms and objects, compiled and transferred the results to the PX-8.  Using the trick of renaming the file zork1.dat I successfully ran the game which was a nice moment.

Despite my attempts to keep descriptions as short and concise as possible the PX-8’s display doesn’t really lend itself to the task at hand, the story file will however of course run on a wide variety of retro machines so I still hope to create a decent end product.  I rather feel as though deciding to create a text adventure for the PX-8 was akin to deciding to create a new blend of tea for a chocolate tea pot but never mind.

Oh and before the pedants jump on me, I’m aware of the slightly odd notion of using compass bearings aboard a ship in orbit around Saturn but hey ho.

Here is some rather shaky footage of game running on the PX-8:-

I’ve had what you might call a senior moment, or a Doh! moment.  Andy over at the Vintage Computer Forums pointed out that Infocom games do of course come as two separate files, the game file (.dat) and the interpreter (.com) so I’ve had an interpreter for CP/M all along.

I downloaded some example story files in .z3 and .z5 format, moved them via floppy to my Windows 95 box and then via filink to the PX-8’s ram disk.  After copying Zork1.com from 5.25-inch floppy to the ram disk I tried changing the names of the story files to zork1.dat.  This did the trick for the .z3 files which loaded and ran, the .z5 files however would not work.

The current situation then is I need to find a way of creating my adventure and compiling it into a version 3 story file in order to play it on the PX-8.  This makes sense really as the the file size limit for version 3 files is 128K.

In the meantime I continue to map the layout of the game and create object and room descriptions.  I want to keep these concise, not only to preserve memory but to ensure they will suit the PX-8’s 80 column 8 line display.  I also have clear ideas for a few puzzles which I hope I can implement.