DOS ain't dead - The Doszip Commander version 2.44 available

The Doszip Commander version 2.44 available (Announce)

posted by nidud , Norway, 03.01.2013, 13:25

> Hi, just a few comments, not sure how useful I am, but anyways ....

Your comments are always both insightful and useful Rugxulo ;-)

> There is a VXD/TSR package (w/ srcs) for WinXP available online.
> Lemme find it ... ntold096b.zip.
>
> I also have here an old (untested) DOSCLIP.ARJ (w/ srcs?) from Veit
> Kannegieser that lets the clipboard API work in pure DOS. (This may
> be hard to find as I don't think his site is online anymore. It may work
> well, which is why I kept it, but I dunno.) Okay, here it is: dosclip.arj

I am aware of the alternatives, and I keep a note in the DOSZIP.TXT file
with address to http://www.phatcode.net/downloads.php?id=188

> IIRC, GNU Emacs (DJGPP port) supported the clipboard, but it was
> limited to a portion of conventional memory due to design. So that may
> be the real limit.

The code of the clipboard interface is very small, but you then have direct access to the linear address of the file. You could then copy 500M directly from the file to the clipboard, and also paste to the file the same way. I started to implement this in the source code, and the interface is something like this:
;---------------------------------------------------------- emm_91: ; Clipboard Copy 91h ;---------------------------------------------------------- ; AL: handle ; DX: start line ; SI: start offset ; BX: end line ; DI: end offset ; CX: line size
To do this in pure DOS you either provide streaming, allowing appending to the clipboard in chunks, or include a clipboard interface in JEMM.

> > The maximum number of open files is currently set to 100.
> Depends on external factors too. But that's probably a reasonable guess.

The limit is the number of handles in the EM-Manager, which is 255-1.
The information block for each file is currently 90 byte, and this is allocated on the stack, which are around 23K. I think the maximum number that worked was around 160, but above this crashed. 100 are a safe number, and the Save/Open Session function is also limited to 100.

> > The maximum number of lines in a file is 65535, and the maximum
> > length of a line is 1024 byte.
> Again, that sounds reasonable, I've very rarely run into anything
> beyond those limits.

There are a few factors to these limits:
- the size of a line cannot be smaller than the screen columns.
- the line is allocated on the stack for manipulation.
- the lines must fit in a memory page (4000h).

Post reply

Complete thread:

The Doszip Commander version 2.44 available - nidud, 02.01.2013, 20:06 (Announce)
- The Doszip Commander version 2.44 available - Rugxulo, 03.01.2013, 10:46
  - The Doszip Commander version 2.44 available - nidud, 03.01.2013, 13:25
- The Doszip Commander version 2.47 available - nidud, 20.03.2013, 17:03
  - The Doszip Commander version 2.47 available - Rugxulo, 21.03.2013, 18:22