Article View: comp.lang.postscript
Article #6991VM and operand stack limitations
From: Chris Langford
Date: Tue, 15 Mar 1988 16:35
Date: Tue, 15 Mar 1988 16:35
60 lines
2215 bytes
2215 bytes
Hi there,
I have been working on a little bit of PostScript code that prints
out digitized electrical signals. We collect neurobiological data, and
thus have to collect lots of data (14 k samples/sec for several 10s of
seconds at a time).
There are two problems I have:
1) The operand stack will only hold 500 objects, so I am (I think)
forced to have 100s of K of data broken down into groups of 500.
2) The virtual memory has only 174 K at most, and thus I must limit
the amount of data I can print per page to about 13K samples (about a
second worth of data).
I have been able to get our program to save data in nice bunchs of
450 (with brackets around it and everything), and do a restore before
I get a VM error, but it is still a real pain in the ass to print.
My questions are:
Is there any way to get the operand stack to accept a larger number of
objects, or bypass it altogether (I have not been able to get anything
else to work)?
Is there a way to get the LaserWriter to dump its font dictionarys,
and thus create more available memory?
Are there any other ways you can think of to get around this problem?
I know the serverdict password, so if it requires some monkey business,
I can handle it.
I have simplified the routine, but it
basically goes like this (if it helps):
[array of 450 integers here]
/data exch def
0 data 0 get moveto
0 2 data length 1 sub
{
data exch dup
/xval exch def
get
xval exch lineto
}
for
stroke
I have 2 channels of data alternating, so I do the same procedure
twice, but have the "for" loop begin with:
0 1 data length 1 sub
to get the other half of the data printed out.
Thanks for any help.
Chris Langford
tektronix!reed!langford
Technical Details
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Path: arc1-ca.pugleaf.net!utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!tektronix!reed!langford From: langford@reed.UUCP (Chris Langford) Newsgroups: comp.lang.postscript Subject: VM and operand stack limitations Message-ID: <8483@reed.UUCP> Date: 15 Mar 88 16:35:28 GMT Organization: Reed College, Portland OR Lines: 60 Keywords: virtual, memory, operand, LaserWriter