PostScript 1.0 – A Code Study(ztoz.blog)
ztoz.blog
PostScript 1.0 – A Code Study
https://ztoz.blog/posts/postscript-code/
5 comments
I've been writing a PostScript interpreter as a retirement project. I deliberately avoided looking at the Adobe source although I have been running the LaserWriter firmware[1] in MAME[2].
At the moment I'm just implementing the language. The core interpreter is done apart from error handling and a ton of operators. After that I'll decide whether to go on to the imaging.
[1] http://beefchicken.com/retro/laserwriter [2] https://github.com/mamedev/mame/blob/master/src/mame/apple/l...
At the moment I'm just implementing the language. The core interpreter is done apart from error handling and a ton of operators. After that I'll decide whether to go on to the imaging.
[1] http://beefchicken.com/retro/laserwriter [2] https://github.com/mamedev/mame/blob/master/src/mame/apple/l...
I'm curious about the history of the base language reportedly designed at Evans & Sutherland 1971ish. I couldn't turn up much in the few minutes of searching I did. If anyone can provide links to papers or anything on this subject I would appreciate it.
As a a starting point, "The Origins of PostScript" (https://gwern.net/doc/design/typography/2018-warnock.pdf) provides a few details on the language and Gaffney's involvement. Warnock's oral history for the Computer History Museum (https://www.computerhistory.org/collections/catalog/10273875...) also includes the story. Gaffney's patent provides the most detail but, unfortunately, it is written as a patent rather than a language description.
The DoD DTIC service has a couple of reports that cover the Harbor Pilot Simulation, but I haven't found any reports written by E&S. The Computer History Museum has some records from Evans and Sutherland, but I don't think any of them cover the language.
The DoD DTIC service has a couple of reports that cover the Harbor Pilot Simulation, but I haven't found any reports written by E&S. The Computer History Museum has some records from Evans and Sutherland, but I don't think any of them cover the language.
Thanks, but I saw that much, I should have been clearer. I'm hoping for something on the scale of a survey if not a paper.
Honestly, my first curiosity regards whether Chuck Moore and Forth get any mention or whether this is a true parallel development, possibly necessitated by the hardware at hand. My perception, based on zero evidence, was that Forth had some influence on the design of Postscript.
Honestly, my first curiosity regards whether Chuck Moore and Forth get any mention or whether this is a true parallel development, possibly necessitated by the hardware at hand. My perception, based on zero evidence, was that Forth had some influence on the design of Postscript.
Apparently not. From "The Origins of PostScript" mentioned by GP:
> The architecture suggested by John Gaffney was to be based on a fictitious stack machine (at that time we had no knowledge of a similar approach taken by the Forth language).
That is the only mention of "Forth".
> The architecture suggested by John Gaffney was to be based on a fictitious stack machine (at that time we had no knowledge of a similar approach taken by the Forth language).
That is the only mention of "Forth".
That led me to this presentation on the Eidophor projector https://www.youtube.com/watch?v=3-BvMcqEc98
If you want to get fancy, look at Suns NeWS. Its basically PostScript but built out with additional features, OO, processes and so on. This could have been the official BSD alternative to X. But sadly Sun didn't open it.
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It actually can be simplified a bit more, and the explicit recursion can be removed entirely, since there's already a free operand stack.