We thought that all the details were out about Tandon’s OEM disk drive contract with Amstrad Plc for 3.5 20Mb Winchesters were out in January – a $50m to $60m contract for up to 20,000 a month (CI No 609), but the news is suddenly causing Tandon’s shares to dance for joy in the US – up $0.75 to $6.50 in heavy trading, but up from a lowly $3.50 a week ago – on formal announcement of the deal as $50m of business during 1987 with $30m for delivery in the first half – but the agreement is only in principle.