Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!uwm.edu!rutgers!njin!princeton!phoenix!bskendig
From: bskendig@phoenix.Princeton.EDU (Brian Kendig)
Newsgroups: comp.sys.mac
Subject: Re: Typewriter Emulation Software for the Mac?
Message-ID: <13007@phoenix.Princeton.EDU>
Date: 17 Jan 90 18:17:02 GMT
References: <7538@shlump.nac.dec.com>
Reply-To: bskendig@phoenix.Princeton.EDU (Brian Kendig)
Organization: Systems Engineering, NASA Space Station Freedom Project
Lines: 48

In article <7538@shlump.nac.dec.com> eirikur@ddif.enet.dec.com (Eirikur Hallgrimsson) writes:
>>In article <25b3ec78.6cbb@polyslo.CalPoly.EDU> rcfische@polyslo.CalPoly.EDU (Raymond C. Fischer) writes:
>>|I don't beleive this is possible.  Not that the software would be especially
>>|difficult to write; it probably would take only a day or two.  The problem
>>|is that the ImageWriter (like most dot-matrix printers) does not print 
>>|characters one at a time.  It collects an entire line of text then prints
>>|it all at once.  Thus, characters are a uniform size and evenly spaced.
>
>I don't think this is true from my own experience doing fancy things with
>printers.  If it was true of the Imagewriter, it would still be perfectly
>possible to fake the desired behavior by "printing" a line containing one
>character at a time, or better yet, by doing something in graphics mode.

Sure!  The approach of 'printing' a line containing one character at a
time would work fine - until you came up against a person who wanted to
print more than one character on each line.

I know what you're saying - you want the ImageWriter to print each
character as it receives it, without sending a linefeed.  The problem
is that the ImageWriter was not built to do this.  Characters are
bufferred until a linefeed is received, at which time the entire line
is printed.  Therefore you can EITHER print one character at a time
each on a seperate line, OR more than one character on a line all to
be printed at the same time (when a linefeed is received).

You *might* be able to fake it by sending one character, then a
carriage return (without a linefeed), then a space and another
character, then another CR, then two spaces and a character, and so
forth ad nauseum, but even a mediocre typist would outrun this method
in no time, and the physical abuse it puts the printer mechanisms
through would not be desireable.

Doing it in graphics mode is not possible either - usually, bitmapped
fonts are too tall for the print head to draw all in one pass.  By the
time you've drawn the entire letter, the print head will be at its
bottom - unable to go back up to draw another character on the same
line.

The bottom line: If you want a typewriter, you'd be best off buying
one rather than simulating one.

     << Brian >>

-- 
| Brian S. Kendig      \ Macintosh |   Engineering,   | bskendig             |
| Computer Engineering |\ Thought  |  USS Enterprise  | @phoenix.Princeton.EDU
| Princeton University |_\ Police  | -= NCC-1701-D =- | @PUCC.BITNET         |
|   Systems Engineering, NASA Space Station Freedom / General Electric WP3   |