[comp.lang.postscript] display list vs. buffering

capslock@wet.UUCP (Allen Crider) (12/27/89)

In article <1751@tfd.UUCP> geller@tfd.UUCP (David Geller) writes:
>
>Can anyone assist me in compiling a list of PostScript compatible
>devices that use display lists and banding versus entire page buffering?
>Thanks.
>
 I believe the only machines that use buffering are Varityper, Autologic
and devices using the Ultre*Setter as a recorder. I'm not sure if either of 
these implementations construct their page buffer from a display list or not.
Building the buffer randomly might lead to excesive disk fragmentation,
while building a display list, "imaging" the resulting bitmap to a large
sequential file, and then passing out the file to the recorder is slow.
  Autologic has a wonderful solution to the problem of buffering to disk--
use DRAM instead. They sell an interpreter with 48 megabytes of RAM.
  In any case, I believe full page buffering to disk slows everything down
except in cases where the "display list only" interpreter can't keep up with
the recorder, such as printing halftones or very complex page descriptions.
  Full page buffering may be required for recorders that can't maintain pixel-
level accuracy during a start-stop-start imaging cycle.

jae@c-art.UUCP (Yukon Kid) (12/28/89)

In article <886@wet.UUCP> capslock@wet.UUCP (Allen Crider) writes:
|In article <1751@tfd.UUCP> geller@tfd.UUCP (David Geller) writes:
|>
|>Can anyone assist me in compiling a list of PostScript compatible
|>devices that use display lists and banding versus entire page buffering?
|>Thanks.
|>
| I believe the only machines that use buffering are Varityper, Autologic
|and devices using the Ultre*Setter as a recorder. I'm not sure if either of 
|these implementations construct their page buffer from a display list or not.

The most common (and fastest) PostScript interpreter found writing 
`in stripes' (you do not want to buffer a 2500dpi image) to hi-res 
output devices such as the Ultre Setter or ECRM Pelbox is the Hyphen 
PostScript interpreter.  The interpreter is found in many brands of
high resolution typesetters.

Send me e-mail if you're interested in Hyphen's PostScript interpreter 
running under Unix on Sun or Apollo.

-john

John Eadie   _Computing Art Inc_ (416) 536-9951  FAX (416) 530 0714 
Studio #303, 25 Liberty St, Toronto .. jeadie@Sun.COM | jae@c-art.UUCP

`these deepest problems are in fact *not* problems at all.' - Wittgenstein