Editing Telesoftware

{{Short description|Transmission of software via teletext}}
{{Use dmy dates|date=April 2022}}
The term '''telesoftware''' was coined by W.J.G. Overington who invented the concept in 1974;<ref>{{cite magazine |last=Overington |first = W.J.G. |title=Telesoftware |magazine=[[Computing (magazine)|Computing]]  |date=May 1977 }}</ref> it literally means “software at a distance” and it often refers to the transmission of programs for a [[microprocessor]] or [[home computer]]  via broadcast [[teletext]], though the use of teletext was just a convenient way to implement the invention, which had been invented as a theoretical broadcasting concept previously. The concept being of producing local interactivity without the need for a return information link to a central computer. The invention arose as spin-off from research on [[function generator]]s for a hybrid computer system for use in simulation of [[heat transfer]] in food preservation, and thus from outside of the broadcasting research establishments.<ref>{{cite web |url-status=live |archive-date=Jan 30, 2023 |archive-url=https://web.archive.org/web/20230130171118/https://research.aston.ac.uk/en/studentTheses/analogue-simulation-of-heat-transfer-in-the-thermal-processing-of |last=Overington |first=W.J.G. |date=1975 |website=[[Aston University]] |language=en |access-date=7 August 2023 |title=Analogue simulation of heat transfer in the thermal processing of food |url=https://research.aston.ac.uk/en/studentTheses/analogue-simulation-of-heat-transfer-in-the-thermal-processing-of}}</ref> 

Software bytes are presented to a terminal as pairs of standard teletext characters, thus utilizing an existing and well-proven broadcasting system.<ref>{{Cite journal |last=Hedger |first=J |date=September 1978 |title=Telesoftware: Using Teletext to Support a Home Computer| journal=IEE Conference Publication 166 |pages=273–276}}</ref>

==History==
Telesoftware was pioneered in the [[United Kingdom|UK]] during the 1970s and 1980s,<ref>{{cite journal |last1=Gazzard |first1=Alison |date=2015 |title= Extending the Aerial|journal=View: Journal of European Television History and Culture|volume=4 |issue=7 |page=90 |doi=10.18146/2213-0969.2015.JETHC083 |doi-access=free }}</ref> and a paper on the subject was presented by R.H. Vivian (IBA) and W.J.G. Overington at the 1978 [[International Broadcasting Convention]].<ref>{{Cite journal |last=Roizen |first=Joseph |date=February 1979 |title=IBC 78 — The 1978 International Broadcasting Convention| doi=10.5594/J10449 | journal=SMPTE Journal | volume=88 |issue=2 |pages=119–122|doi-access=free }}</ref>

The world first test broadcast took place on [[ITV (TV network)|ITV]] [[ORACLE (teletext)|Oracle]] in February 1977, though there was no equipment available to use the software at that time. The broadcast simply produced a display of the encoded software, for a [[Signetics 2650]] microprocessor, on a teletext television. However, the fact that the broadcast took place gave the concept practical credibility of something that was realistically possible for the future.

At the 1978 International Broadcasting Convention a demonstration of telesoftware working from a live feed of ITV Oracle teletext was presented on an exhibition stand by Mr Hedger. The Oracle signal being carried within the ITV signal. At one stage the ITV signal was routed via a communication satellite as part of a television demonstration, and the opportunity was used to test telesoftware using that signal that had been routed via the communication satellite, and it worked well.

Also, a display maquette, with the title Telesoftware Tennis had been broadcast live for a few minutes on ITV Oracle in November or December 1976. Although that was just during a discussion of the future possibilities for telesoftware, the development in the 21st century of retrieving teletext pages from [[S-VHS|super-VHS]] recordings means that if anyone was recording the ITV television broadcast on super-VHS videotape at that time, then that maquette page could potentially be recovered from the tape by teletext archaeologists, as potentially could the broadcasts from 1977 mentioned above and the broadcasts made in 1978 at the time of the International Broadcasting Convention. Such technique has already been used to recover and archive telesoftware broadcasts made in the 1980s by the BBC.

During that time, software was broadcast at various times on all of the (then) four terrestrial [[TV]] channels. Telesoftware and tutorials were available on [[Ceefax]] ([[BBC]] teletext service) for the [[BBC Micro]] via its [[BBC Micro expansion unit#Teletext adapter|teletext adapter]] between 1983 and 1989<ref>{{cite web |url=http://teletext.mb21.co.uk/gallery/ceefax/telesoftware/index.shtml |title=Teletext Gallery - BBC Ceefax Telesoftware |website=The Teletext Museum |publisher=Mike Brown |access-date=19 October 2017 }}</ref> and was generally transmitted for a period of one week. The BBC Ceefax Telesoftware service was managed by Jeremy Brayshaw.<ref>{{cite magazine |author=<!--Staff writer(s); no by-line.--> |title=Ceefax Telesoftware Axe Storm |magazine=[[The Micro User]] |volume=7 |number=8 |page = 12 |date=October 1989 }}</ref> Most of the Telesoftware programming tutorials were written by Gordon Horsington<ref name="GH"/> and they, as well as most of the software, are still available from the online Telesoftware archives (see the external links below). Gathering of the software (often referred to as "downloading", though, as there was no uplink request needed nor used, not really "downloading" as such) could take place from Friday evening to the following Thursday evening. As the updating took place on a Friday, it was advised not to attempt to gather the software between 9&nbsp;am and 7&nbsp;pm on Fridays.<ref name=GH>{{cite magazine |last=Horsington |first=Gordon |title=Free BBC Micro software on Ceefax: What can you receive - and how |url=http://myweb.tiscali.co.uk/themicrouser/issues/05-03/telesoftware.htm |magazine=[[The Micro User]] |volume = 5 |number = 3 |date=May 1987 }}</ref>

Other channels provided for several other computers via a range of adapters and [[set-top box]]es. The same delivery system was also used to deliver satellite weather images from the [[Meteosat]] satellite for download.<ref name="Closure"/>

Although none of the early telesoftware initiatives survived,<ref name="Closure">{{cite web |url=http://teletext.mb21.co.uk/gallery/ceefax/telesoftware/closure.html |title=BBC Announces Closure of Telesoftware Service |date=1989 |access-date=19 October 2017 }}</ref> many of the techniques are now at the heart of the latest [[digital television]] systems.

Various archives of BBC Ceefax Telesoftware are preserved on the internet.<ref>{{cite web |url=http://www.g7jjf.com/telesoftware.htm |title=Telesoftware |date=17 August 2010 |publisher=Jon Welch |access-date=19 October 2017 }}</ref>

== See also ==
* [[ORACLE (teletext)]]
* [[Multimedia Home Platform]]
* [[BASICODE]]
* [[Timeline of teletext in the UK]]

== References ==
{{Reflist}}

{{BBC Computer Literacy Project}}

[[Category:BBC computer literacy projects]]
[[Category:Computer-related introductions in 1983]]