[comp.sys.amiga] Strangeness when copying to RAM:

wecker@cookie.dec.com (DAVE TANSTAAFL WECKER) (12/08/86)

I'm confused (so what else is new :-). When using Matt's shell to copy a file
to the RAM: device, the following happens:

	238k free	- at start of copy
	153k free	- near end of copy (file is 85k)
	 68k free	- at VERY end of copy (looks like during close)
	153k free	- after copy completes

It looks like before finishing the copy, AmigaDOS eats up TWICE the size of
the file (this is using the AZTEC-C runtime routines on V1.1 of the O/S).
So just for grins, I did the standard copy command in c: and got:

	238k free	- at start of copy
	150k free	- near end of copy (file is 85k)
	135k free	- at VERY end of copy (looks like during close)
	150k free	- after copy completes

Not as bad... but still 15k disappears (for an instant). What is going on?
Is this a known bug? Do I have any control over it? Is it fixed in 1.2?

The problem arises when I want to run EMACS, VT100 and a MAKE at
the same time. When I get to the point where I want to copy c.lib up to
ram: (and there should be enough room) I run out of space (since I need 170k
of ram (for an instant) to hold the c library instead of 85k).

Any input would be appreciated.
Thanks,
dave	{decwrl|decvax|decuac}!cookie.dec.com!wecker

page@ulowell.UUCP (Bob Page) (12/09/86)

wecker@cookie.dec.com (DAVE  TANSTAAFL  WECKER) wrote:
> [test]
>It looks like before finishing the copy, AmigaDOS eats up TWICE the size of
>the file
> [another test]
>Not as bad... but still 15k disappears (for an instant). What is going on?
>Is this a known bug? Do I have any control over it? Is it fixed in 1.2?

I run with PM (the Performance Monitor, graphics display of cpu/mem usage)
on all the time, and have noticd this also.  It does not seem to make a
difference what the size of the file is ... there is some overhead always.
Even back when I was playing with the RESIDENT command (stay away from it)
it would do it, so it's not as simple as the COPY program being there.

My guess is that either COPY is doing something funky or there is some
misc bizzarness occuring with the RAM: handler.  Knowing AmigaDOS,
would you be willing to bet that it (COPY or the RAM handler) allocates
large chunks of mem when copying?  Speed demon that it is?

..Bob	(constantly amazed at the `features' of AmigaDOS)
-- 
Bob Page,  U of Lowell CS Dept.      ulowell!page,  page@ulowell.CSNET