Limit and advisability to delete an answer
I recently incur in this question ("Can EXE always be replaced with COM?") and in the deleted answer that I report below for the users that have no access to the deleted questions.
It is an upvoted answer (~70), with many version (5) made by the author, with more than 15 comments. It must have been popular in the summer vacation period
I have no problem to recognise some inspiration as proposed by other users, but I can see even some work in cutting the not essential parts (in relation to the question), a general paraphrase of the other page, some personal additions (
in Z-80 / 8088 code).
We usually deprecate to post one-link answer asking to report the main points: here it missed the link (now there is one), but I cannot be sure that the author takes really that page as inspiration, or another page on internet (in principle even older) as starting point.
Nonetheless there is some personal work that differentiates the original blog page with the answer, and it is possible that someone finds it more clear and readable than the accepted one.
Note that the accepted answer was posted some hours after the deletion of this one, with the explicit link to the blog page, a similar paraphrase that simplify even more the concepts expressed and with the addition of a link to a stackoverflow similar question.
So I'm asking myself and to you all:
- is it that enough to mark as plagiarised and delete this answer (and others like this) ?
is it not a damage for the normal user that the answer is deleted and not any more accessible (even more in consideration with the fact that it was really highly upvoted and so many people just thought it was useful)? In general the information inside the deleted answer should be get lost...
is it not the case to undelete it, maybe with a critical note that states the absence of the source link, and let the people read and decide?
Thanks for your time.
The deleted answer in its last form
[paraphrased from Raymond Chen, Microsoft - What’s the difference between the COM and EXE extensions?]
In the beginning of MS-DOS (and CP/M) the only programs that existed were COM files.
A COM file was just a memory image (in Z-80 / 8088 code). To load a COM file, the loader used to put the file into memory and started it at the first byte.
The COM file format had the problem that programs were limited to 64KB. To manage that limitation the EXE format was introduced. The EXE file has a header that begins with the letters "MZ" and includes information that the loader uses to load the program into memory. COM files were "raw memory images" and EXE files were more "structured".
Over time the original MS-DOS programs like FORMAT.COM, EDIT.COM and COMMAND.COM grew larger than 64KB and they had to be changed to EXE, but it meant a compatibility problem with a lot of software produced in the past. It was solved by giving the loader the flexibility to check if the file begins with "MZ", independently of the extension, so as to know if it is a "structured" or "raw" file.
So nowadays it doesn't matter what the extension is (COM or EXE) because the loader will recognize the header and will manage the file accordingly.
answered Aug 11 '16 at 13:26 jcbermu