confusing file extension, not user-friendly

The older formats are documents from the older versions of Mathcad.  Prime is unable to read those files directly, it launches a separate application that starts Mathcad 15 (available free with Prime) to read the file and translate it (or try to) into "Prime language."

Prime 3.1 can't even save into Prime 3.0 file format (both .mcdx of course), and Prime 3.0 can't read a Prime 3.1 file. So I think there's more chance of pigs flying than Prime ever writing Mathcad 15 files!

manit churanakoses wrote: I'm  wondering whether PTC has any intention in providing user-friendly features for updating and saving Mathcad files. There seem to be several file  formats: mcd; xmcd; xmcdz; mcdx; and so on.  And they are not all compatible and interchangeable. ... Why can't PTC do the  same for  new versions of Mathcad to help  facilitate Mathcad customers to save the file to any formats: mcd; xmcd; mcdx; or whatever...

No, they aren't compatible, because Mathsoft (Mathcad's original developer) and PTC have introduced capabilities that aren't well catered for by the older formats; Mathcad 12 introduced the xml format (xmcd and xmcdz) that was a radical departure from previous formats (unless you count MathML).   As Luc has mentioned, Mathcad (not Prime) can save worksheets back about 3 or 4 versions, but can read further back.

I suspect that the lack of backwards save capability is deliberate, to essentially force users to upgrade to Prime, isolate themselves on whatever version they happen to have, or to abandon Mathcad altogether.  At the moment, most users of older versions can still have some interaction with users of the most recent versions of Mathcad, but that will diminish over time as Mathcad 15 is phased out. Unfortunately, the capability gap between Mathcad 15 and Mathcad Prime is still too great to entice a number of users to migrate to Prime (especially when coupled to the cost of such a move and the expense of annual maintenance).   On the other hand, we had similar issues with the transition from Mathcad 11 (which was rather good) to Mathcad 12 (which was .. not good), but over time people have drifted up to Mathcad 14 or Mathcad 15.  Historically, though, there have always been users who are reluctant to upgrade as their "older" version meets their needs and/or they had concerns over the teething problems that went with major releases.

Although Mathcad Prime Express is a good idea, I suspect the PTC pricing structure is going to be a significant barrier to Prime uptake ... A Mathworks-like pricing whereby I could, say, pay £25 to add programming and have an optional pro-rata maintenance, would be far more appealing.

In reference to other good speadsheet program, Excel;

"Other" good spreadsheet program?  I wouldn't classify Mathcad as a spreadsheet program ... far from it.

Excel; although they have been upgraded though several versions of file formats, they  still keep its compatibility and interchangeability with the  old legacy version.  For example, you still can save the latest Excel file format of XLSX to the old legacy of XLS.

That's not quite true.   I (that is my company) have just upgraded from Excel 2003 to Excel 2007 and I have already hit several backward compatibility issues.   Yes, I can still save a file as .xls, but I lose information and capability. The same problem can arise in other major applications, the differences between Python 2 and Python 3 being a good example. Nothing like the difference between Mathcad versions, though!   It wouldn't be quite so bad if PTC had retained a human-readable xml format rather than using a compressed form.

Stuart