home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.os.msdos.misc
- Path: sparky!uunet!charon.amdahl.com!pacbell.com!att-out!cbfsb!cbnewsg.cb.att.com!rnichols
- From: rnichols@cbnewsg.cb.att.com (robert.k.nichols)
- Subject: COPYing binary files (was Re: Help: Software is here, printer is there)
- Message-ID: <1992Nov18.033431.12290@cbfsb.cb.att.com>
- Sender: news@cbfsb.cb.att.com
- Organization: AT&T
- References: <1992Nov15.010641.28325@leland.Stanford.EDU> <1992Nov16.232453.17042@spang.Camosun.BC.CA>
- Date: Wed, 18 Nov 1992 03:34:31 GMT
- Lines: 38
-
- In article <1992Nov16.232453.17042@spang.Camosun.BC.CA> dbarker@spang.Camosun.BC.CA (Deryk Barker) writes:
- ...
- >Try using the /b(inary) qualifier to the copy command. Trying to do
- >the same thing to a HP IIP I got a similar result. Using /b cured it
- >(and, I think, removed the necessity for a manual press of the
- >FormFeed button); strangely enough I have *never* have to use /b when
- >copying executable from disk to disk.
- ...
-
- The DOS "COPY" command has a built-in set of rules about whether to
- use ASCII or BINARY mode as a default. It uses BINARY mode whenever a
- simple image copy is known to be safe. Otherwise, it assumes ASCII
- mode. Thus:
-
- 1. Copying a single file to another single file is done in binary;
- whatever the old image represented, the copy wil be just the
- same.
-
- 2. A many-to-many copy (using wildcards) is also done in binary,
- since it is just multiple instances of case 1.
-
- 3. Concatenating multiple files onto a single target defaults to
- ASCII, since there may be terminating CTRL-Z characters that
- need to be stripped out in order to make a valid ASCII target.
-
- 4. Copying to a target device "known" to be ASCII is, of course,
- performed in ASCII mode. (... and we all know that printers,
- COM ports, and the like are ASCII devices, right? Well, "COPY"
- is pretty certain that they are, anyway.)
-
- Binary and ASCII modes are a relic of the CP/M filesystem, with which
- DOS still maintains a degree of compatibility (and you thought that
- 8088 compatibility was the only boat anchor that DOS was still dragging
- along!).
-
- Bob Nichols
- AT&T Bell Laboratories
- rnichols@ihlpm.ih.att.com
-