The thing that makes PDF less attractive than plain Postscript is that it is a 
binary format.  PDF is "object" oriented; Postscript is "stream" oriented.  You 
have to construct a binary table-of-contents at the end of a PDF file with 
byte-offsets into the file referencing a tree of PDF objects.  And, it still 
has to be converted to Postscript to send to a printer.  Whereas, a Postscript 
file can simply be sent to a Postscript printer directly.  I know of no native 
PDF printers.  Postscript is a text file; you can edit it with a text editor 
and not mess it up.

On 29 Feb 2016, at 12:48 PM, <[email protected]> 
<[email protected]> wrote:

> Date: Mon, 29 Feb 2016 14:04:09 -0500
> From: Timothe Litt <[email protected]>
> To: Paul Koning <[email protected]>
> Cc: [email protected]
> Subject: Re: [Simh] KS10 IMP documentation
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="windows-1252"
> 
> On 29-Feb-16 13:05, Paul Koning wrote:
>>> On Feb 29, 2016, at 12:59 PM, Timothe Litt <[email protected]> wrote:
>>> 
>>> ...
>>> I created a printer class driver layer for simh when I did PDF output for 
>>> all the emulators, but that went into a black hole of "more is not enough" 
>>> and did not find its way into simh/master.
>> I looked at PostScript output for a printer, which is fairly easy and makes 
>> it possible to do non-ASCII characters if the particular machine needs 
>> those.  In the end, I did it as an external program (small Python script) 
>> instead, but in SimH would certainly not be hard.  PS has the advantage that 
>> it's easy to generate and easy to see what's going on, and it can either be 
>> printed directly, or converted easily to PDF.
>> 
>>      
> PDF is an ISO archival standard and these days, more accessible than
> PS.  To do anything with postscript, you need to get add-on software -
> usually ghostscript.  Pretty much every PC, Mac and Linux box has a PDF
> reader out of the box.  Several web browsers have built-in PDF
> interpreters.  PDF supports non-ASCII characters.  And PDF supports
> embedding other media types.  You can (and I did) support compression
> and embedded images.
> 
> Anyhow, that's what I picked.
> 
> I did the work of generating PDF with green (or blue or ..) bar paper,
> tractor feed holes, background logos, form sizes, overstrike, queuing to
> a spool directory, appending, checkpointing, etc.  I had an escape
> sequence interpreter so anything not in the PDF character set (a
> superset of ASCII) could be generated fairly easily from a SimH driver. 
> I provided translations for 32 character sets, from ASCII to Greek to
> Technical.
> 
> I integrated it into all the simulators - not just DEC.  It didn't
> preclude .txt output.  But it became controversial for reasons not fully
> understood - and I was unwilling to keep implementing non-core features
> for specific host platforms. 
> 
> I had a lot of other pressures on my time.  I gave up.  I still think it
> was a nice piece of work, but clearly the community didn't.
> 
> Anyhow, the point is that it's feasible to build a class driver layer &
> FWIW, my strong opinion is that for LPD bridges and any output formats,
> that's the way to go.  Of course, given my experience, you might want to
> collect other opinions.


Larry Baker
US Geological Survey
650-329-5608
[email protected]

_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh

Reply via email to