THERE HAVE been rumours of discontent about the Sinclair Research method of marketing the Microdrive. The company is offering it exclusively by mail order, working in strict sequence through the list of people who bought the Spectrum by mail order last year.

Jeffrey Law bought a Spectrum from a retailer six months ago because of the promise of the Microdrive. He will not be able to obtain one until the full mail order list is satisfied.

"I want to use one for work," he says, "I now will have to wait for a Microdrive longer than people who bought their Spectrum months after I did."

"The system seems unfair to anyone who bought the Spectrum through the retail trade," says Mike Meek, head of the Sinclair User Club. The company disagrees.

"The Spectrum was available solely by mail order from April to November last year," says a Sinclair spokesman, "and it is only fair that people who bought it then before it became widely available should be first served now."

He adds that anyone who bought the Spectrum over the counter can still write to Sinclair Research and ask to be added to the end of the Microdrive mailing list.

It could be several months before Sinclair Research works through the list.

"It depends on the take-up rate," says the spokesman. So far, the response to the Microdrive offer has been very high but demand may tail off when the eager early birds have been satisfied.