Path: utzoo!attcan!uunet!munnari!vuwcomp!windy!srwmcln
From: srwmcln@windy.dsir.govt.nz (Clive Nicolson)
Newsgroups: comp.lang.postscript
Subject: Re:PostScript compatible printers
Message-ID: <1714@windy.dsir.govt.nz>
Date: 25 Jul 88 13:19:34 GMT
Organization: DSIR, Wellington, NZ
Lines: 29

The following infomation may be of help to people considering PostScript
compatible printers and PostScript fonts.

A number of Adobe PS (PostScript) fonts seem only to be available in real
Adobe PS printer, a further selection of fonts can be purchased from Adobe
in forms that can be downloaded to PS printers from either MAC's or MSDOS
machines. These downloadable fonts are in the form of a PS program. This
program is composed of some material which is in the clear (ie not encrypted)
and a large amount of stuff which is HEX and feed to the eexec operator.
The eexec operator takes either a file or a string which is encrypted and
calls the interepter with this file/string as its currentinput. All input
from this source is decrypted by the file system of the interpreter. This
(encrypted) input is just more PS program, and typically contains a mixture
of ordinary PS and HEX for the cexec operator. The cexec operator takes
either a file or a string of unencrypted HEX and treats it as a relocatable
module of machine code. For Adobe PS interpreters this will be M68000 code.
The code module contains relocation infomation and a (largely) PS version
independant linkage mechanism to the rest of the interpreter.
It is very unlikely that Adobe tells anyone how cexec or eexec work. This means
that PS clones can not provide Adobe fonts. They can however provide similar
fonts from other sources ie bit mapped or BitStream outline fonts.
If you are buying a PS printer one should ask about its ability to use Adobe
fonts, clones may have an acceptable alternative to your requirements; and of
course may be cheaper.
The outline above of Adobe fonts is only a taste of the tricks found in their
font files.

PS. I'm not knocking PS printers of any sort, just make sure that the printer
you buy does what you want.