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-
- In late 1992, I had access to an old Atari ST version of Hollywood
- Hijinx, which ran amazingly quickly under Frank Lancaster's Zip
- interpreter for the Acorn Archimedes. I also had a new PC version
- of Planetfall which I had to play under slow PC emulation, since
- Zip only understood version 3 games. After a quick search using
- Archie, I found a copy of the ITF 4.01 sources on an FTP site and
- started working; the versions of Mark Howell's Zip interpreter
- which I found only supported version 3.
-
- By January 1993 I had a simple port running in character mode and
- two things happened. Firstly, Edouard Poor released a similar
- port, which ran a simple character mode screen in a window (and so
- allowed it to multitask) and which seemed to be a month or two
- ahead of my efforts. Secondly, the C SDK arrived for my new Psion
- palmtop, and I suddenly realised that it should be possible to
- cram the interpreter and a decent game into a machine that I could
- carry in my pocket.
-
- The first simple port to the Psion (1.2) was released around
- Easter 1993, and evolved throughout the summer, gaining support
- for proportional fonts, the main motivation being that this
- allowed around 50% more text to be crammed into the 40x9 display
- of the Psion.
-
- By the beginning of the summer, it was obvious that the same
- proportional font techniques, combined with Acorn's anti-aliasing
- outline font technology should allow a much more readable display
- than Edouard's display. The early attempts proved popular, and
- demands for command-line editing were soon incorporated into both
- versions. The Acorn version also sprouted code to handle
- drag-and-drop save and restore operations. This version was
- released as 1.3.
-
- Shortly after this, Oliver Wagner released a port of Mark Howell's
- Zip interpreter to the S3. While lacking the proportional font
- support of my port of ITF, it did make better use of the Psion
- menu system. However, the patches needed for the O/S integration
- on the Acorn made it trivial to supply save/restore menu
- operations on the Psion. The updated version was released as
- version 1.4.
-
- By the end of the summer, the Psion and Acorn versions seemed to
- have stabilised, and we had some O'Reilly X documentation lying
- around the office. The resulting simple port was circulated as a
- Sparc binary around Oxford, but the general messy state of the
- source code, which was half original ITF and half windowing system
- was much too hideous for a general X11 release.
-
- Work continued on reorganising the source code with two aims in
- mind; firstly to make it clean enough for a supportable X11
- release, and secondly to make it possible to cleanly add support
- for the new Psion Series3a, with its enhanced screen size and
- standard mechanism for switching font sizes while running. The
- 1.5 versions (all internal) followed this, and when the patches
- for the 3a were fully operational the version number moved to 1.6
- as versions were released.
-
- During the months following the early releases, the redraw
- handling code was revamped several times to improve performance
- and remove bugs when handling InvisiClues, the memory pager was
- finally fully modularised, the Psion interface code was split into
- overlays, the font handling was corrected from the ITF approach to
- the Zip approach, and the Psion paging mechanism refined to
- massively reduce memory consumption. The X11 interface code was
- then updated to cope with the new data structures, and work
- started toward producing a release for three platforms as 1.7.
-
- Time permitting, many more changes are required. The approximate
- support for real-time features present in the original ITF release
- and stripped from this version needs to be fixed and reinstated.
- The handling of some obscure version 5 opcodes needs to be fixed;
- in general usability has been of more concern than the accuracy of
- the interpreter. While this version is more faithful than the ITF
- sources it is derived from, it is not as accurate as Mark Howell's
- Zip interpreter.
-
- Looking further ahead, the continuing excavations by Mark Howell,
- Graham Nelson and others suggest that it may well be possible to
- support V6 games at some point.