Drawing a circuit diagram

It's been mangled, not surprised. There should have been 14, 8 bit sequences representing the letters "This is EBCDIC" when coded as EBCDIC not ASCII. The 0x40 for space has survived but I can't (be bothered to) figure out what has happened to the others.

Reply to
Dave Liquorice
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I need to mull that over (more coffee first) - I think everyone's talking apples and oranges here... :-)

Yes, I think we're having two discussions here - one about published standards v proprietary, and one about the ease of interpreting the data when no kind of formal specification (open or otherwise) is available.

Yes and no. A huge amount of PCs won't read FM-encoded data from a floppy (which was the norm for a considerable period of time) and will only handle MFM (far fewer still will *write* FM, but that's less of an issue for most folk). The modern controllers just don't handle it. Similarly there are issues around sector size (128-byte sectors seem to trip up a lot of modern controllers), hard-sectored drives, drives which can vary spindle speed etc.

I'd agree that if it were written on an old IBM-compatible PC though then it'll generally be readable on a modern IBM-compatible PC via a combination of software and the right flavour of drive.

Yes, AIUI DXF was designed with a certain amount of "human parsability" in mind, so for the purposes of doing the job that DXF was designed for there wouldn't really be any longevity benefit in using plain text instead; if there was no software around that understood DXF natively, you could still open the file in any old text editor, read the contents via eyeballs, and work out what the contents 'mean'.

From a longevity point of view, the best formats are definitely the ones where a human stands a chance of being able to make sense of the contents by looking at the file 'raw' and make few* assumptions about how the information is encoded.

  • I was going to say 'no', but as has been discussed there is still the need to know that the contents are ASCII, or EBCDIC, or some double-byte unicode thing.

cheers

Jules

Reply to
Jules

same goes for bloody postcript.

OR PLT format.

Reply to
The Natural Philosopher

Heh, OK. I was looking at it on the wrong side of 7am and not sure if I were missing something obvious :-)

Reply to
Jules

lol. maybe draw them as @

NT

Reply to
NT

_Any_ OS, thats the point. ASCII is the one thing that pretty much every computer today understands.

Take an example: .mmm format used in win3.1. Do you think that will be supported in 50 years time? I expect writers will have long since quit bothering to support it, just as today's OSes have quit bothering to support formats from early computers. By then the only OSes/apps that will be able to handle .mmm will only be compatible with what will then be extremely historic hardware, such as 1990s PCs. Add the fact that the skill set to set up win3.1/98 will have long gone, and it'll be a mountain to climb just to view your data.

I've already been thru this cycle with a format I used in the 90s, which nothing else supported in 2000, and the original hardware finally died. Data recovery was successful but time consuming.

Any machine can display ascii, its a semi-worldwide massively cross platform standard. ASCII is a good option for archival for this reason.

sometimes today its the only _practical_ way. Now fast forward 50 years

That too. I can smugly count on my huge ASCII library being readable for life. People that save in messier formats can't. Computers will probably change out of recognition over the next 50 years.

Indeed. I suspect that may have ceased to be a problem though, in that I/we can now store all our data on a HDD or two (plus backups), and move it from one machine to the next over a lifetime. Thus the obsolete media issue should no longer arise. (that dreaded word 'should')

Guess I'm stumped with those 8" 400k discs then.

in several cases none exists, and that just over a 20 year period. Imagine another 50 years.

ASCII is the one standard that virtually every computer reads. Add to that that plain text will continue to be needed indefinitely, and there's no reason to move to a new standard, and you've got a very long term format.

Its not at all.

That might be true for professional archivists, but for most of us we're never going to write software in 30 years time to enable display of the then historic .jpg format. Either software is available to use on existing machines of the time or it isn't. When software that will run on computers of the time is not available, the data is usually as good as lost.

NT

Reply to
NT

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