creator wrote:
On Oct 24, 11:26 am, schmidtd <schmi...@my-deja.com> wrote:On Oct 24, 1:34 pm, Patrick Schaefer <PSchae...@lycosxxl.de> wrote:> > However I have never heard of such backup software, which I assume would> need to store whole-disk images to the tape, in whatever format. Did it > actually exist back in the day?"Disk-O-Tape" by Dann McCreary. Distributed on cassette, around 1980. It works like ADT, reading raw sectors and writing them to tape.After reading what writeups are available via Google, it sounds like it would be fun and easy to write. If only it were useful today! Come to think of it, why would it have been useful in the day anyway? For archival purposes so that you could re-use diskettes, maybe. But you need a physical diskette to reconstitute the data anyway...?FYI, I originally wrote "Disk-O-Tape" for myself because at that time a simple blank 5-1/4" floppy diskette cost about $5 (in 1980 dollars!) and I could buy cassette tape 3-packs for as little as a buck! :) That's five bucks to save 128K bytes!!! "Disk-O-Tape" turned out to be a pretty popular seller (relative to my other simulation software) probably because of that cost disparity. I also was able to distribute the program (and others) on a cassette because it incorporated a "bootstrap loader" with a short one-liner typed into the Apple II monitor. Of course it took about 15 minutes to save a full diskette, and another 15 minutes to do a sector-by-sector compare/verify after rewinding the tape... but SHORT diskettes would save/verify lots quicker.
I'm guessing that (like a lot of programs) it was bought and then used just once after the buyer realized the "15 minutes" part. ;-) In early 1981, Verbatim 10-packs were available for $25 (US) at my computer club. $2.50 wasn't cheap, but it was a reasonable tradeoff, since ten diskettes would usually last me a couple of months or more. You have to type pretty fast to create over a megabyte of data in that time, even allowing for backups. ;-) -michael NadaPong: Network game demo for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."