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Tesler’s Law of Conservation of Complexity:
You cannot reduce the complexity of a given task beyond a certain point.
Once you’ve reached that point, you can only shift the burden around. Larry Tesler
Tim Mott was a Brit working for the Xerox subsidiary and textbook publisher Ginn & Co. He was asked to liaise with Xerox PARC to see if they might help with manuscript editing and typesetting requirements.

Mott looked at POLOS, the PARC OnLine Office System. Bill English, Bill Duvall and Doug Fairbairn had developed this as the first real attempt at PARC’s goal of an office of the future system. To use POLOS an operator needed to learn by rote a series of arcane commands and key sequences; this was also the case with early WordStar software.
Mott was disparaging, finding it too complex to master and suggesting that not enough reality checks had been included in the project thinking. Bob Taylor challenged him to stick around and come up with something that would satisfy his requirements.

Mott worked on this with Larry Tesler who had been the strongest internal critic of POLOS at PARC. They looked at the rudimentary word processing packages that were starting to emerge on the market and felt that the PARC-grown Bravo, while the best available at the time, was still deficient in user-friendliness. In particular they disliked its concept of ‘modes’.
Michael Hiltzik in his very informative and entertaining book ‘Dealers of Lightning: XEROX PARC and the Dawn of the Computer Industry’ quotes an amusing critique of the modes used by Bravo,
‘…This involved a user who inattentively typed the word “edit” while in command rather than text mode: Typing “e” selected the entire document. ‘d’ deleted the selection, and ‘i’ instructed the machine to insert in its stead the next character to be typed… at which point the user discovered that his entire document had been inalterably replaced by the letter ‘t’.

1975 Mott and Tessler set out to use the mouse and graphics capabilities of the Xerox Alto more thoroughly; they named the software Gypsy. This was to be the first truly WYSIWYG word processor.
There were only four completed Altos at the time they started the task and Tesler and Mott considered that possession was more than nine-tenths of the law; while ‘their’ Alto was in use it could not be reallocated. Sharing one Alto they each worked fourteen hours a day, with an hour overlap at the beginning and end of their sessions to hand-over. In this way they held on to their Alto 24/7!
This creative tension produced many features that we use today – dialogue boxes, cut-and-paste, drag-through and mouse double-clicking.
In 1975 Ginn & Co had a $41m turnover and 20% of its 284 staff were engaged in what was then termed as content editorial. Following this work it was forecast that Gypsy might reduce their costs by anything up to 20 percent; clearly significant!
This exercise was certainly the first real-life utilisation of a PARC-developed technology.

Tesler would move on to work with Apple, Amazon.com and Yahoo!
Mott became a VP at Electronic Arts and later was one of the co-founders of Macromedia.
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