1TB sata internal harddrive

an external drive would be more practical for this...

In reply to a post by ggremlin:

betamax ?, 8inch floppy?, rl02 ?,

Widespread was the key word

SInce the 80's maybe, but the 70's or 60's or 50's?

in 20 probably even 50 years.

Such a short view of history. We are not necessarily talking here of JPEGs or episodes of Heroes as MKV files, although historians will find any they can find (assuming they have not been deleted) fascinating. We are talking about what are often bespoke file formats and some are also encrypted. In the decades to come, it is quite possible that the last records of profoundly important people, events and the rest might as well have been written in some proto-Cro-Magnon script because they are utterly indecipherable to man or machine.

Punch cards? I'm not sure if anyone else encountered this one, but there was a period in the 70's (I assume that it was some transitional point between punch cards and mainstream magnetic media) when it was not uncommon to find these things littering the streets. Who knows what was hidden therein and whether all of it made its way into newer formats or was just dumped?

A perfect example here. Only 25 years and the data is practically unreadable.

Having said that, in this case the situation is entirely under the control of the OP. He only has to make sure that as well as storing the data he stores the programs necessary to access that data and the hardware to run them on.

We're talking file formats here, not hardware type. If you need to be able to ensure that you can read the hardware in 50 years, just keep the computer along with the disk. Simples.

Empty assertions.

That depends on what you call 'external'. I'm sure I'm not alone in using caddyless drive trays and eSATA.

Not al all. I have encountered an issue where there were CAD files for a building. Unfortunately, they were the original architects had used some software to create them that few had heard of and then archived them on tape in a format that even fewer people had heard of. Try as we might we couldn't find anyone who could make all this into DWG (aka AutoCAD) files. Our last hope lay in the structural engineers, who used DGN (aka Microstation), which can be readily converted to DWG, but unfortunately, they had ceased to be and all their electronic files had gone with them. Thus we were reduced to scale rules and at significant cost employing a team of surveyors.

8 inch floppy disks were extremely widespread in their day. They were the de facto standard for storing and moving data on minicomputers.