Are you sure your disc drive has stopped rotating, or are you just ignoring the messages?

Did this story make you angry? Y/N

On Call Roll up, roll up, to On Call, your weekly instalment of fellow readers’ tech triumphs and frustrations.

This time, we meet "Noel", whose story is bound to make you cringe and scream in equal measure.

"Many years ago, when 8-inch floppy disc drives were leading edge technology, I programmed and installed a system for a supermarket chain in the north of England," he told us.

"Staff at the supermarkets would wander along the shelves looking to see what needed to be restocked," he said.

They would request replenishment by blacking out squares on a large, pre-printed form, which were sent to head office.

Once there, they were placed manually into an optical mark reader, which was interfaced to a mini-computer.

The mini-computer was programmed to write the products and quantities onto an 8-inch floppy disk.

The disk then went to another department, which worked out what products to put into which lorries for delivery to the supermarkets.

So far, so sensible.

However, the people using the optical mark readers "were not very technically savvy", Noel said.

"This was before the days when everyone had a computer at home – so I had made the program REALLY, REALLY easy to use."

This involved a series of straightforward prompts that walked users through the steps, and asked them to simply stab one key to move to the next stage. For instance, "Have you placed a floppy disc into the machine? Y/N."

One day, though, Noel had a call from an operator to say that their disc drive had stopped turning.

Noel said that even though that was clearly a hardware problem, he had gone to investigate, "because it sounded unlikely that either the drive motor had stopped, or that the operator would have been able to recognise that condition".

When he arrived, Noel was proved right – there was no hardware problem, just user error.

Because there was a floppy disc in the drive – it was just that the disc drive door open. On the screen was a message: "The disc drive door is not closed. Please close it."

Noel closed it, and everything worked. So why hadn't the operator seen, and acted on, the message?

"Well, we know we have to type Y, and then N, and then Y, when we start work, but no one has ever explained why," came the reply.

Noel was flabbergasted. "None of my careful, simple messages had ever been read."

But he still wasn't satisfied – how was it that the operator had come to the conclusion that the disc drive had stopped rotating?

"It was because the characters on the screen had stopped moving (it was simply displaying the "close door" message)," he said.

The operator had assumed that the role of the screen in all this was that "as the disc rotated, the characters that were displayed on the screen were read off it".

Since the characters on the screen had frozen, the user had felt that, "clearly, the disc had stopped rotating".

Summing up his experience, Noel simply said: “Oh dear.”

Oh dear, indeed.

But we're sure Reg readers everywhere will have plenty more "Oh dear" moments to share. Drop On Call an email now – and don't worry, we keep it all anonymous, so your naive users are spared their blushes. ®