Reminiscence
Machine code programming used an unusual form of octal, known locally as 'bastardized octal'. It represented 8 bits with three octal digits but the first represented only two bits, whilst the others, the usual three.
Within English Electric, its predecessor, DEUCE, had a well-used matrix scheme based on GIP (General Interpretive Programme). The unreliability of valve machines led to the inclusion of a sum-check mechanism to detect errors in matrix operations. The scheme used block floating-point using fixed-point arithmetic hardware, in which the sum-checks were precise. However, when the corresponding scheme was implemented on KDF9, it used floating point, a new concept that had only limited mathematical analysis. It quickly became clear that sum checks were no longer precise and a project was established in an attempt to provide a usable check. (In floating point (A + B) + C is not necessarily the same as A + (B + C) i.e. the + operation is not associative.) Before long, however, it was recognized that error rates with transistor machines was not an issue - they either worked or did not! Consequently the idea of sum checks was abandoned. The initial matrix package proved a very useful system testing tool as it was able to generate lengthy performance checks well before more formal test packages which were subsequently developed.
Legend has it that the KDF9 was developed as project KD9 (Kidsgrove Development 9) and that the 'F' in its designation was contributed by the then Chairman after a long and tedious discussion on what to name the machine at launch - "I don't care if you call it the .......". (See also KDF8 for the parallel development and use of a commercially-oriented computer.)
The Egdon operating system was so named because one was going to UKAEA Winfrith: in Thomas Hardy's book The Return of the Native Winfrith Heath is called Egdon Heath. Their Fortran was called Egtran. Eldon was so named because Leeds University's computer was located in a converted Eldon chapel.
During the "foot and mouth" trauma of 1968, the Grand National was run on English Electric's Bureau KDF9 in Hartree House, Queensway, London with Raymond Glendenning leaning over the back of the line printer, reading the printout to the world on BBC radio.
Read more about this topic: English Electric KDF9
Famous quotes containing the word reminiscence:
“Visit the Navy-Yard, and behold a marine, such a man as an American government can make, or such as it can make a man with its black arts,—a mere shadow and reminiscence of humanity, a man laid out alive and standing, and already, as one may say, buried under arms with funeral accompaniments.”
—Henry David Thoreau (1817–1862)
“One seems to believe almost all that they believe; and when they stop short and call it a Religion, and you pass on, and call it only a reminiscence of one, should you not part with the kiss of peace?”
—Thomas Carlyle (1795–1881)
“A man, yet by these tears a little boy again,
Throwing myself on the sand, confronting the waves,
I, chanter of pains and joys, uniter of here and hereafter,
Taking all hints to use them, but swiftly leaping beyond them,
A reminiscence sing.”
—Walt Whitman (1819–1892)