Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!apple!uokmax!norlin
From: norlin@uokmax.ecn.uoknor.edu (Norman Lin)
Newsgroups: comp.sys.atari.8bit
Subject: Creative Computing lightpen (was Re: Atari trivia)
Message-ID: <1991Jun3.024300.20748@uokmax.ecn.uoknor.edu>
Date: 3 Jun 91 02:43:00 GMT
References: <1991Jun3.002321.2267@mnemosyne.cs.du.edu>
Distribution: usa
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK
Lines: 55

mmiller@isis.cs.du.edu (Mark Miller) writes:

>> Some interesting trivia, but I have one correction: Atari finally DID
>>release a lightpen (I used to have one). I think they did so in '84. It
>>came with its own special cartridge drawing program, which was really
>>quite nice (IMHO). I was impressed at the time that they hadn't merely
>>repackaged Koala Paint, as they had done for the Atari Touch Tablet.
>>Speaking of light pens, you can make your own: There was an article on
>>the subject in a very early issue of Creative Computing (now defunct).
>>It may have been 1981. Then there was the Atari Paint program, which used
>>a joystick for input.

>I believe I know which article you're talking about.  I have that Creative
>Computing issue.  It is March 1983, in the "Outpost: Atari" article.  It
>mainly talks about how to make a home-made Atari light pen, and gives a
>couple sample BASIC programs you can use with it.

>What is surprising is this is an issue of Creative Computing that I just
>happened to look at and pick up one day.  You are the second person I have
>heard refer to this article (I think you were referring to this one) after
>all these years.

I built this lightpen.  You mention that you "just happened to look at and
pick up" this issue of Creative Computing; similarly, I was browsing through
back issues at the library.  What was a bit annoying was that the pinouts
given for the lightpen were REVERSED; this was not mentioned until a few months
later in another issue.  But since I was looking through back issues at the
library anyway, it wasn't until about 2 years later that I happened to
stumble upon that correction article, during which time the lightpen had been
scrapped, rebuilt a few months later exactly as per (incorrect) instructions,
failed again, scrapped, rebuilt, failed...

When I finally found the correction article and got the lightpen working,
though, it was less than impressive.  The vertical resolution was perhaps
fine enough for vertical discrimination among the 24 different graphics 0
lines; horizontal resolution was nowhere near being able to pinpoint which of
the 40 columns you had the pen pointed at.  And for drawing, the pen was pretty
much useless.  They included a sample drawing program in graphics 7.  Vertical
resolution was almost acceptable, but the horizontal resolution was so poor
that you would get a point +/- about 40 pixels from where you were, which in
graphics 7 is abysmal.  The article did mention that horizontal resolution was
poor, but I didn't expect it to be that poor.  Did anyone else have better
results with this lightpen?

Ah, the days when you could build your own computer peripherals and easily
interface them... what memories...

>Mark Miller
>mmiller@isis.cs.du.edu

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