Bad Disk Formatter

[+CharlieChaplin]

Well, in the early 80s (around 1981-1984) there was a program named "Bad Disk Formatter". It did NOT create bad sectors, instead it was used to format disks that had one ore more defective sectors. The program marks these sectors in the VTOC as "in use" and therefore unavailable to DOS 2. It is therefore limited to DOS 2.0 and single density (90k)...

 

My friends practice back then was to simply throw away (non-original/non-commercial) disks with bad or defective sectors. But other Atarians kept them, because they were so expensive back then. (Besides, the PC also formats 5,25" and 3,5" disks with bad or defective sectors and marks them as not available).

 

Nowadays 5,25" disks are getting more and more rare (and expensive again) - so my question is:

Would you still use bad/defective disks and format them with this Bad Disk Formatter or do you think this is too risky and it is better to throw away such A8 disks ? (As said before, non-original/non-commercial disks.)

 

 

[Keatah]

Problem with aging disks that have bad sectors, even if you map them out, more bad ones are gonna pop up. It's getting to be about that time.

[+Larry]

BURP! (Basically Unusable (Disk) Reclaimer Program, IIRC) From Analog magazine, Charles Bachand. It was republished in the Compendium of Issues 1-9. Don't remember the exact original issue -- maybe 8 or 9-ish.

 

Additionally, you would be surprised how many disks could be rejuvenated by using a bulk eraser (mainly for reel-to-reel type tapes). Later, the better Chrome (etc.) tapes required a higher-powered de-magnetizer.

 

However, if the disks are physically damaged, shedding oxide, etc. all bets are off. I routinely used the bulk eraser on good disks that I wanted to restore to "like new" status, prior to making a disk copy of something important.

 

-Larry

[AtariGeezer]

BURP is on Side A, others on Side B too...

BasicDiskUtils01B.ATR

BasicDiskUtils01A.ATR

[Mclaneinc]

I remember those back in the day but never touched them as I 1. worked for Maplin so had disks galore and 2. decided a bad disk would most likely get worse (cheaply made etc) so never trusted them to any data.

[vitoco]

I'd use old disks only to store some XEX with a boot loader and use that disk in a retro meeting for the experience.

 

I'd neither use those disks to store unique pieces nor if they could damage the disk drive.

[1050]

Too risky for me to run them on my drives, I like clean heads to

stay clean as long as possible. Good idea for a hard drive back

when they were expensive, just my opinion but say 15 sectors bad

on a floppy isn't going to make or break me. I don't use them

for bulk file storage anyway.

 

But seeing and talking about the software for it is pretty neat

just the same, thanks for that.

[Rybags]

I'd use them but only for stuff where it doesn't matter if the disk is lost like downloaded games.

 

What such a program needs is 3 paranoia settings -

1. mark returned bad sectors unusable.

2. mark entire track unusable.

3. mark adjacent tracks unusable as well.

 

Possibly an option for adjacent sectors too but that would be something that varies depending on interleave.

[Keatah]

4. mark entire disk unusable.

[Rybags]

5. HCF

 

 

 

 

Halt and Catch Fire

 

 

 

 

[Stormtrooper of Death]

In the 80s I wrote a simple fast Format program for the 1050 drive. It could reformat a floppy in only 2 seconds but just writing the directory information (of an empty formated floppy) to the floppy. Extra handy was that the Atari automatically noticed bad sectors and adapted this to the free available sector count.

[+Larry]

In the 80s I wrote a simple fast Format program for the 1050 drive. It could reformat a floppy in only 2 seconds but just writing the directory information (of an empty formated floppy) to the floppy. Extra handy was that the Atari automatically noticed bad sectors and adapted this to the free available sector count.

 

Got it handy somewhere? Basic or ML (and if ML do you still have the source code?)

 

-Larry

[Rybags]

You'd need a small ML component at least for the disk I/O calls.

 

All that's needed is to write the boot sector and VTOC sector/s, then zero out the directory sectors, optionally zero out sectors 2, 3 - so it could be done algorithmically and fairly compactly.

The real trick would be to do one that handles the different Dos formats as well as the different densities and sector sizes.

[Stormtrooper of Death]

 

Got it handy somewhere? Basic or ML (and if ML do you still have the source code?)

 

-Larry

Is was made in ML (Atmas II assembly language).. And no , I lost the source code. Might try to recreate the program. Shouldnt be that difficult.

[Kyle22]

That sounds like the SDX Build Directory function in the formatter.

 

There is no way you could do a full format and map out bad sectors in 2 seconds.

 

Edit: I had to correct the iPhone autocorrect

Edited March 26, 2017 by Kyle22

[Rybags]

Yep, you have to wait for the drive to return the info. And you only get a maximum of 64 (?) returned, although using a disk with more than several bad sectors would be a pretty bad idea.

 

Have to wonder though, why Atari's Dos didn't use it with it's format command. I suppose given that the default for years was to use write with verify plus they went with a piddly density to start with, there was a bit of paranoia about it. There would have been a bit of extra programming needed but I would think that most of what's needed would already be present in the FMS.

Edited March 26, 2017 by Rybags

[Kyle22]

I agree.

[Mclaneinc]

Do any of you guys totally rely on real floppies and not have a digital copy as well?

 

I only ask as some of you are pretty hardcore about 'keeping it real'.

[+Larry]

I think Paul raises a very good point. If all my stuff were on hard copies (including physical disks) my house would be overrun. Many years ago when I saw the advantages of ATR images, I started on a campaign of getting rid of physical disks. I've probably gotten rid of a thousand or more, mostly 5-1/4". So hard to imagine my early Atari days when my entire software collection could be contained in a single 10-pack of disks!

 

My interest in the "bad format" subject is just a continuing curiosity of how things in the Atari actually work. And also, it makes for a neat little utility. Which also means that I need to go back and study the original Analog article of BURP!

 

-Larry

[tep392]

Do any of you guys totally rely on real floppies and not have a digital copy as well?

 

I only ask as some of you are pretty hardcore about 'keeping it real'.

I've started a Ms. Pac-man Arcade that will be programmed entirely on my 800xl. Right now the files exist only on floppy. I'm keeping multiple floppy backups.

[Mclaneinc]

Apart from the best of luck with the game are you not even the slightest bit worried about disk failure even with the odds sort of stacked in your favour?

 

I admire your integrity though, making an Atari game on an Atari completely.....Much props for that.. :thumbsup: :thumbsup:

[Keatah]

Do any of you guys totally rely on real floppies and not have a digital copy as well?

 

I only ask as some of you are pretty hardcore about 'keeping it real'.

 

I used to. But not any more. While I have all my originals, I don't count on them. I've kept ATR images and DSK (for apple II) images from the 1990's and early 2000's, and while they are not as old as a floppy from 1979, I have high confidence the disk images will last another 50 years minimum.

 

That includes a little bit of freshening up and migrating over time. Something you HAVE TO DO with disk images. And of course there are backups!

[Keatah]

On the Apple II, I have a utility that does the same thing. Ran it on a lot of my disks back in the day and it reported only a few bad sectors here and there. But it could do nothing, absolutely nothing, to predict what would happen in the future. What sort of degradation would happen over the years.

 

And what it certifies today, counts only for today. Not tomorrow. Unlike modern Flash and Hard Drives. Classic hardware can't tell if a sector is weak or not. It's either enough to fire off the pre-amp and flip the logic gates, or it isn't. There is no in-between No "weak" sector that "should" be refreshed or reallocated. By the time that happens, the data is gone and would need forensic reconstruction if at all possible.

[tep392]

Apart from the best of luck with the game are you not even the slightest bit worried about disk failure even with the odds sort of stacked in your favour?

 

I admire your integrity though, making an Atari game on an Atari completely.....Much props for that.. :thumbsup: :thumbsup:

I'm a little worried, but I can reduce the risk by keeping multiple backups and using new disks as I make significant progress. If something happens and I loose a file, I'll have earlier revisions to fall back on. I'm also using new in box disks that I purchased from Athana and should be less than 15 years old. Drive's have all been adjusted to spec as well. Thanks for the wishes of good luck. I probably need it.

[Keatah]

Keep a head-cleaner disk around. As even new old-stock disks just 10 years out can shed oxide.