OK, I'm lucky enough to have prototypes of a videotext system using the
Mattel Aquarius computer. I have hardware, and more importantly software,
manuals, and some videotext specs. I've got the things the guys used to
design their hardware - that is, the low level detail. I also have some 25
year old printouts of videotext screens. Rather neat. Contact me if you
want copies, basically at cost - or I will dig out particular information
gratis.
Cheers
A
-----Original Message-----
From: Jack Peacock <peacock_at_simconv.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Saturday, March 21, 1998 5:20 AM
Subject: Re: information
Turlough O'Brien wrote:
"videotext" but there is little to no information available on the
net about "Videotext" or in the libraries.I would greatly appreciate it if
you could send me some informatin on the subject.
(This is from memory and unreliable) There was a proposed standard
for North America called NAPLPS, for videotext presentation. I believe it
was sponsored by Philips. If someone has a complete collection of BYTE
magazines, I recall there was an issue devoted to videotext, circa 1981.
The one clever feature of NAPLPS was that the graphics were based on
floating point coordinates. Because screen sizes and resolutions would
vary, positioning and sizing graphics was a problem. NAPLPS used a
coordinate system where the width and height of the screen ranged from 0 to
1. For instance, to place a pixel in the center, you referenced coordinates
(0.5, 0.5).
Videotext never really caught on in the US except on cable TV as a
non-interactive display. I believe there are still a few videotext services
piggybacking on satellite channels. They transmit on one of the unused scan
lines at the top of the picture, similar to closed captioning for the deaf.
To my knowledge the only truly successful videotext implementation
was the french minitel telephone directory.
Hope this gives you a place to start.
Jack Peacock
Received on Fri Mar 20 1998 - 14:36:22 GMT