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Lawrence Woodman
May 7th, 2009, 01:11 AM
I've been thinking more about CP/M recently and have become really quite interested in doing more with it. I have never used a CP/M machine with a HDD, so am curious how people used to backup their HDDs under CP/M; were there tape drives readily available?

While we are on the subject, how did business users tend to backup their diskettes?

I know that backups were often rarely done, but I guess that some must have done them.

Chuck(G)
May 7th, 2009, 02:41 AM
A very few systems had QIC tapes; even fewer had 1/2" tape, but setups for both existed. Floppies were generally used for backup.

Interesting story here.

In 1979, I submitted a program to Lifeboat Associates for consideration. It was program to back up a hard disk to floppies (one could span a file over several floppies). I still have the rejection letter--Lifeboat didn't think that hard disks were ever going to be common enough that there would be a market for such a program...

At the time, I was using a 14" Shugart SA-4000 winchester with a staggering 40 MB of space. I still have the thing. The room lights dim when you turn it on...

patscc
May 7th, 2009, 07:39 AM
Backups are an on-going problem. It seems backup devices have always been lagging behind hard drives in terms of price and capacity, unless you end up using another HD as backup.


Lawrence Woodman said...backups were often rarely done
You're right about that, I've even ran across people that still didn't back up after a major HD crash, applying the logic of lightning never strikes in the same place twice.

patscc

Chuck(G)
May 7th, 2009, 09:02 AM
The odd thing about a lot of backup media is that it was less robust than the disks it was backing up.

I've got a ST506 (4MB) drive sitting on the shelf that still has the data I wrote to it when I took it out of service more than 20 years ago. On the other hand the DC-1000 (10MB) tapes of the backups are unreadable. Many users with old DC-600-sized carts have seen the cartridges degrade.

I think a distinction has to be drawn between "backing up" and "archiving". "Backing up" carries the implication that the need is short-term--a couple of years tops. The medium has to be cheap enough to make frequent backups practical.

Archiving, on the other hand, implies long-term storage of data and is a real problem. CD-Rs and DVDs are probably as good as it gets; 1/2" magtape after that, probably. Stone tablets are great, but have an information density problem.

Terry Yager
May 7th, 2009, 11:58 AM
Speaking from personal experience: All of the above, only more so...

--T

Lawrence Woodman
May 8th, 2009, 12:12 AM
Archiving, on the other hand, implies long-term storage of data and is a real problem. CD-Rs and DVDs are probably as good as it gets; 1/2" magtape after that, probably. Stone tablets are great, but have an information density problem.

You are right about archiving. I seem to be continually moving my backups from one medium to the next to ensure that I can still read the backups. At least these days we can do that relatively inexpensively.

Chuck(G)
May 8th, 2009, 02:53 PM
I've had a number of conversations with professional archivists who are struggling with preserving the detritus of the computer age. I recall asking about how one goes about selecting an appropriate medium to preserve the information that is recovered from all of those disintegrating tapes and floppies.

The answer shouldn't surprise anyone: "Paper, whenever possible. Paper can last centuries if it's made right and taken care of. And we know how to make paper and care for it."

leeb
May 9th, 2009, 01:25 PM
Interesting comment there....
While on that,

anyone still have a working paper-tape punch?

Or maybe a Hollerith card punch?

I hit computers only shortly after them, and fortunately managed to preserve my most-important-none-more-important files/prgs from 8" to 5 1/4" to 3 1/2" to CD/CD-R/DVD-R...
but, I STILL have a few examples of the punched-cards my older brother used when he took a computer class 'way-back-when'! :rolleyes:

I focused more on getting my pascal-based assembler working to be concerned with backup software... strange huh. But I did have about 25-30 copies lying around...

Hard to know which was newer, cause they didnt have labels on 'em.

Go figure. :mrgreen:

Dr_Acula
May 9th, 2009, 04:14 PM
Re Chuck(G) "The answer shouldn't surprise anyone: "Paper, whenever possible. Paper can last centuries if it's made right and taken care of. And we know how to make paper and care for it."

I agree. The domesday book is nearly 1000 years old.

I had a (free) program about 10 years ago that could print out a 1 megabyte floppy disk onto a single sheet of paper using dots. It worked best with a laser printer as sometimes inkjets would smudge. Then to read it back you could put the piece of paper through a scanner. It was similar to this http://www.paperdisk.com/id1.html

Or print out the text of a program. I've got disks I can't read any more but still have the paper printouts and if desperate, can always key them in one line at a time.

But perhaps for more permanent storage, how about clay tablets, or chisel the binary data into stone?