Path: utzoo!attcan!uunet!decwrl!adobe!heaven!glenn From: glenn@heaven.woodside.ca.us (Glenn Reid) Newsgroups: comp.lang.postscript Subject: Re: 7 vits vs. 8 bits (again) Message-ID: <187@heaven.woodside.ca.us> Date: 27 Jun 90 10:45:18 GMT References: <9006270115.AA21371@terra.oscs.montana.edu> Reply-To: glenn@heaven.UUCP (Glenn Reid) Organization: Skyline Press, Woodside CA Lines: 54 In article <9006270115.AA21371@terra.oscs.montana.edu> uphwk@TERRA.OSCS.MONTANA.EDU (Bill Kinnersley) writes: >Ulp, I don't want to get in between Woody and Glenn on this, but actually >guys, PostScript is an 8 bit language, not 7. True. It supports 8 bits, but it is possible to express all programs in 7 bits, which is partly why I called it a 7-bit language. >In fact, Aldus PageMaker produces PostScript files which contain 8-bit >non-ASCII characters. As far as I can tell, this is perfectly legal. Perfectly legal often means that "it prints" on the one printer somebody tested it on.... It's perfectly legal, but tends to cause all manner of problems when the file is moved from the Macintosh environment. This is mostly because the world at large can't be assumed 8-bit clean. Serial ports have parity bits set; modems, software, electronic mail transport, bad cables--there are lots of places to lose the 8th bit. For good portability, you have to stick with 7 bits. But the point, as I remember it, was that it's not the serial port that is limited to 7 bits. In fact, the 8th bit has nothing to do with things like control-C, control-D, etc. It's the standard serial line PROTOCOL that treats these characters as special. And although, as Woody points out, it is possible to circumvent some of these with things like DTR/DSR, it's not guaranteed, and not always possible, depending on lots of things. The original discussion had to do with emulating other printers and how come you couldn't pass arbitrary binary data down through the serial port, which does present a bit of a problem. We've been haggling over just where the problem lies, but the more I think about it, the less I think I want to use my LaserWriter II NTX as a LaserJet printer anyway. There are over 4000 applications that product PostScript, and I don't own any computers that run software that doesn't produce PostScript. Or something like that. But you're quite right, PostScript can be an 8-bit language. I'm sorry to belabor all of this, but for some reason I always jump in when somebody says something like "Adobe in their *infinite* wisdom...." PostScript isn't everything for everybody, but it's one of the best designed pieces of system software that I've ever encountered. I'd rather use PostScript for those things at which it is wonderful than to complain that it doesn't do a good enough job emulating a brain-dead printer. But I guess things only get better when enough people complain about them :-) Glenn -- % Glenn Reid PostScript consultant % glenn@heaven.woodside.ca.us Free Estimates % ..{adobe,next}!heaven!glenn Unparalleled Quality