Mike Dank's Python Tool Serves Up Slick Pics to the AT&T Sceptre and Other Vintage Videotex Boxes

Vintage technology enthusiast Mike Dank has been playing with an AT&T Sceptre interactive videotex terminal — and for in case there's anyone out there who's doing the same, has released an open source server that can sit at the other end of the connection feeding it graphics.

"naplps-server is written in Python and designed to be used w[ith] a modem so you can take calls from your NAPLPS videotex terminal and serve it graphics," Dank explains of the software. "Works with the AT&T Sceptre and probably others. Works great with a phone line simulator, BUT there is also a demo phone number up (or direct SIP details) to try. Warning: that might break if the client disconnects unexpectedly or data corrupts. More work to do!"

Videotex was one of the first remote information terminal systems to implement graphics, offering a fully two-way interactive communication session — unlike one-way viewdata systems like teletext. The North American Presentation Layer Protocol Syntax (NAPLPS), meanwhile, was one of the protocols available for defining the graphics to be shown on the system — encoding images as instructions represented by individual ASCII characters with two-dimensional coordinate data. Developed by Canadian data transmission specialist Norpak, NAPLPS launched as Telidon in 1978.

AT&T's Sceptre videotex terminal was released in 1983, and served as the hardware behind both Knight Ridder's Viewtron service and the Los Angeles Times' Gateway — two of the largest videotex services in the US. Dank's example turned out to be in fully-functional shape, though getting it up and running required a fair bit of trial and error. "My initial attempt at a Python program just sending data [didn't] seem to work," Dank explains. "I used Tera Term to manually ATA [AT command Answer] the incoming call and then I could drag and drop NAPLPS files to transfer in binary mode."

Having proven that the old terminal could still display graphics Dank took what he had learned and developed naplps-server, a software package that sits behind a Hayes-compatible dial-up modem, or suitable modem emulator, and answers calls with a rotating slideshow of NAPLPS color imagery — a unidirectional communication for now, but which could potentially be extended to support two-way interactivity in the future. "I can definitely see how this logic could be modified into a rudimentary BBS [Bulletin Board System]," Dank says.

More information is available in Dank's Mastodon thread, while naplps-server is available on GitHub under the reciprocal GNU General Public License 3.0 — but you'll have to supply a suitable modem and NAPLPS-compatible terminal yourself.