The restriction is aimed at the TI 92 calculator developed by Texas Instruments which has a graphic facility able to perform complex algebraic manipulations involving symbols as well as numbers.
The rapid development of calculator technology has already given rise to anxiety in the Higher Still specialist group on maths. A recent report (TESS, May 31) called for a review of the use of advanced calculators. An investigation is likely to involve the universities and curriculum chiefs as well as the SEB.
Peter Kimber, the board's depute chief executive, commented: "We accept advances in technology and, in the past, we have been able to adjust examination questions accordingly so there is no advantage accruing to candidates with more sophisticated calculators.
"But Texas Instruments have taken us into a whole new ball game and we could not adjust the questions, at least not in time for next year's examinations. So we had to impose this ban."
The conditions, which will apply to all SCE and Certificate of Sixth Year Studies maths exams, are in addition to existing restrictions. The calculator must not be able to communicate with anyone outside the exam hall, to store information which can be used during the exam, or to disturb other candidates with audio or printer facilities. The sharing of calculators is also forbidden.
Mr Kimber added: "The board has, I think, shown in the past that we are not Luddites. We are saying that candidates must be able to show how they arrived at their answers. We also accept that a calculator can be a good teaching aid, not least in allowing pupils to confirm their calculations."
The SEB's letter to schools and education authorities states that the board could be open to persuasion in exceptional circumstances "if it is shown that a specific calculator which contravenes these regulations does not in fact give any significant advantage to the candidate concerned".