Re: Backup Objects HP 49G+
- From: PremiumBlend <mnhollinger@xxxxxxxxx>
- Date: Sat, 28 Mar 2009 16:16:05 -0700 (PDT)
On Mar 28, 1:48 pm, "John H Meyers" <jhmey...@xxxxxxxxxxxxxx> wrote:
On Fri, 27 Mar 2009 21:54:25 -0500, PremiumBlend wrote:
I was pondering the efficiency of creating a new backup
object everytime I update that object. No problem is
encountered when creating the object for the first time.
But, the second time of course you generate an error.
All HP48/49/50 have this safety measure,
to avoid clobbering (storing over) objects stored in ports.
Is purging the existing backup object a logical albeit
inefficient way to handle this?
In between purging an old object and storing a new one,
you are without any backup at all.
I use something like :3:B1234 ARCHIVE (with an SD card),
incrementing the number each time; an SD card can hold
a very large number of backups, so there is no concern
about available space. Numbering makes it easy
to determine which is the latest,
or to purge the oldest, etc.
Having too many objects in the root directory of an SD card
may slow down and clutter the Filer, so one may also
move older objects to any subfolder on the card,
using the Filer, if one wants to keep them forever.
It seems to me that
doing so would accumulate a lot of garbage because
you are recalling a large amount of objects to the
stack in order to back them up over and over again.
What large number of objects?
The ARCHIVE command writes the entire HOME directory,
as a single object (of calculator type 15 -- Directory),
which can be restored using :3:B1234 RESTORE
ARCHIVE over a cable sends a "Backup" object (named "HOMEDIR"),
which contains the same directory; this object can be restored
either directly from the stack, or by first storing to a port.
Backups of libraries may of course also be stored in an SD card, from which
it is easy to restore an entire 49G+/50G calculator in just moments;
it is also easy to convey backups (and all other files)
between a computer and the calculator, on the card.
So an SD card is a highly valuable accessory for an HP49G+/50G
"Don't leave HOME without it" :)
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[r->] [OFF]
Thanks for the response, John!
In between purging an old object and storing a new one,
you are without any backup at all.
Good point. If I was overly concerned about this I guess
I could backup the backup before purging.
I use something like :3:B1234 ARCHIVE (with an SD card)
Good idea. I guess I could set up a loop with a counter
and purge the old objects at a specific interval.
What large number of objects?
I should have written "large object." I guess the stack
uses one reference pointer per object, regardless of the
size of the object, so a 2 KB object is no more difficult
to clean up than a 20 byte object.
.
- References:
- Backup Objects HP 49G+
- From: PremiumBlend
- Re: Backup Objects HP 49G+
- From: John H Meyers
- Backup Objects HP 49G+
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